AC Vacuum Pump and Oil

[Dynomite]

Has anyone used an AC Vacuum pump (gauges) and oil in the case of a break in the AC connections? How do you do it?

[VetteVet]

Cliff,

I'm not understanding your question. Are you asking how to vacuum(evacuate) the freon system prior to charging?

If so, detailed instructions are available in the FSM. Pay careful attention to the type and quantities of oil. The FSM lists how much oil should be present in each of the components. There are variables depending on whether you are changing any components, but the FSM explains it pretty well.

Feel free to PM me if you have any questions. I do marine AC systems on the job and do all of my own AC work on my vehicles.

Jep

[Dynomite]

Cliff,

I'm not understanding your question. Are you asking how to vacuum(evacuate) the freon system prior to charging? Yes.....in the case where you lost it all in a break.

If so, detailed instructions are available in the FSM. Pay careful attention to the type and quantities of oil. The FSM lists how much oil should be present in each of the components. There are variables depending on whether you are changing any components, but the FSM explains it pretty well.

Feel free to PM me if you have any questions. I do marine AC systems on the job and do all of my own AC work on my vehicles.

Jep

Jep......You are definitely DAMAN....appreciate that. I am thinking I can buy a vacuum pump at Harbor Freight or Sears for a couple hundred and set it up on my system for 45 minutes and then re-install Freon 12. I know I lost some oil and need to replace some oil.

Also there is some desiccant of sorts that has to be changed?

That is what I want to do :p

Maybe I am smoking dope.....:D
But then again......I will try anything once.

Darn line broke at Evaporator when I pulled the engine......I got new evaporator (I guess it is the evaporator) and now need a charge.

Oh...almost forgot.... 91' ZR1 is up and running again after some "secret" changes....Extremely smooth idle and ....and...well...you know the rest of the story when it comes to a nicely tuned, ported, cammed, Open Exhaust LT5. I pulled the engine with Headers installed and put engine back in Z same way.....except for the AC issue ;)

[VetteVet]

Cliff,

Vacuum for an hour, then shut gauge manifold valves, turn off vacuum pump and monitor vacuum in system for evidence of any leaks. If none, you're set to charge with the amount of R-12 listed in the FSM. When you connect the can, make sure that you have the can upright and then loosen the fill hose at the manifold to purge the air, then retighten it. The can has to be upright to ensure that you get vapor, not liquid. Charge to the low(suction) side with can inverted until you cannot get any more Freon to flow into the system, then return can to upright position, start engine, leave doors open, switch climate control to auto and set to lowest temp setting. If you don't have enough pressure in the system for the A/c compressor to kick on, disconnect the pressure cycling switch and jump the two wires to energize the clutch. Add remaining Freon to the low side with can in upright position. You don't want any liquid Freon hitting the compressor, as that will damage it. Remember to shut the low side valve when changing cans and also re-purge the fill line. It doesn't take very much air/moisture in the system to seriously degrade performance.

The FSM lays it out very nicely. Shoot me a PM if you have any questions.

Jep

[Dynomite]

Cliff,

Vacuum for an hour, then shut gauge manifold valves, turn off vacuum pump and monitor vacuum in system for evidence of any leaks. If none, you're set to charge with the amount of R-12 listed in the FSM. When you connect the can, make sure that you have the can upright and then loosen the fill hose at the manifold to purge the air, then retighten it. The can has to be upright to ensure that you get vapor, not liquid. Charge to the low(suction) side with can inverted until you cannot get any more Freon to flow into the system, then return can to upright position, start engine, leave doors open, switch climate control to auto and set to lowest temp setting. If you don't have enough pressure in the system for the A/c compressor to kick on, disconnect the pressure cycling switch and jump the two wires to energize the clutch. Add remaining Freon to the low side with can in upright position. You don't want any liquid Freon hitting the compressor, as that will damage it. Remember to shut the low side valve when changing cans and also re-purge the fill line. It doesn't take very much air/moisture in the system to seriously degrade performance.

The FSM lays it out very nicely. Shoot me a PM if you have any questions.

Jep

Jep:
Thank you thank you :handshak:
I will think, study, and think some more and maybe PM you if I have questions......I am not sure about the oil yet but did not loose very much oil as my understanding most of the oil resides in the compressor. I will give it a try....and thanks again.

I am sure anyone who has pulled an LT5 moving the AC compressor out of the way over to the drivers side has prolly done what I did once or twice....pulled too much on the AC line attached to the evaporator :cry:

Cliff

[4-cam]

Also If the system has been opened for any length of time, replace the accumulator/Drier to make sure you have a clean dry system. Cheap insurance as these compressors are expensive.

http://www.rockauto.com/catalog/moreinfo.php?pk=82995&cc=1041297

[VetteVet]

Also If the system has been opened for any length of time, replace the accumulator/Drier to make sure you have a clean dry system. Cheap insurance as these compressors are expensive.

http://www.rockauto.com/catalog/moreinfo.php?pk=82995&cc=1041297

Thanks for the catch, 4-CAM. I had that in my original write-up but brain farted and lost it all. I omitted it when re-typing everything.

Jep

[Dynomite]

Also If the system has been opened for any length of time, replace the accumulator/Drier to make sure you have a clean dry system. Cheap insurance as these compressors are expensive.

http://www.rockauto.com/catalog/moreinfo.php?pk=82995&cc=1041297

Thank you.....appreciate that informaton and source :thumbsup:
Also at Oreilly Auto Parts Murray AC Accumulator/Drier (http://www.oreillyauto.com/site/c/search/Accumulator!s!Receiver+Drier/C1951/C0328.oap?year=1991&make=Chevrolet&model=Corvette&vi=1041297&keyword=ac+accumulators!s!driers) for $43 (for a 91 ZR1) :cheers:

Or Eckler's Corvette has the Air Conditioning Receiver Drier (http://www.ecklerscorvette.com/corvette-air-conditioning-receiver-drier-1988-1992.html) for $25 plus shipping.

And thanks again Jep for the technical information.....appreciate it :thumbsup:

[VetteVet]

And thanks again Jep for the technical information.....appreciate it :thumbsup:

Cliff,

Glad to be of assistance. It's kind of unusual seeing you asking for advice. You're usually the one generously dishing it out.

Jep

[HAWAIIZR-1]

Thanks guys for all the technical info related to A/C. Reading all of this made me decide to leave my A/C service to a professional. I have a new compressor waiting to be installed as well as the drier/accumulator, orifice tube, etc. and will wait until I get back to the US. There is a good shop in Hawaii that identified I had leak from my compressor with some dye in freon before shipping the car in early 2011 that I have not addressed since and will use them when I return. My understanding is I also need some special oil for the brand new compressor according to the supplier.

Craig

[Dynomite]

Reading all of this made me decide to leave my A/C service to a professional.
Craig

Craig.....After all you have done to your ZR1 yourself.....the A/C should be a cake walk ;)

I made the mistake and I would expect others have done the same (maybe) moving the A/C compressor once too many times. I lift it and swing it over on top of drivers side wheel well when removing engine. What I should have done is tie those A/C lines going to the Evaporator down so they do not move breaking the fitting to the A/C Evaporator (right in front of the passenger side).

I have an A/C Vacuum pump from Harbor Freight, A drier from Ecklers, HVAC A/C Refrigeration Kit AC Manifold Gauge Set from Ebay, and some refrigerant. Maybe get some oil also. I will let you know how it goes :D

I really like working on the ZR1s and am getting very efficient at removing the windshield wiper motor, removing the A/C cover on the Evaporator, removing the Transmission, and lifting the LT5 out of the ZR1 (yep...with Headers attached) :p

[HAWAIIZR-1]

Craig.....After all you have done to your ZR1 yourself.....the A/C should be a cake walk ;)

I made the mistake and I would expect others have done the same (maybe) moving the A/C compressor once too many times. I lift it and swing it over on top of drivers side wheel well when removing engine. What I should have done is tie those A/C lines going to the Evaporator down so they do not move breaking the fitting to the A/C Evaporator (right in front of the passenger side).

I have an A/C Vacuum pump from Harbor Freight, A drier from Ecklers, HVAC A/C Refrigeration Kit AC Manifold Gauge Set from Ebay, and some refrigerant. Maybe get some oil also. I will let you know how it goes :D

I really like working on the ZR1s and am getting very efficient at removing the windshield wiper motor, removing the A/C cover on the Evaporator, removing the Transmission, and lifting the LT5 out of the ZR1 (yep...with Headers attached) :p

You might be right and that is what I thought, but I admit I don't know diddly squat about air conditioning systems. I do have an article saved from one of the Corvette magazines that I thought would help. More research and I might be comfortable tackling the job. I just want it right and A/C is important to have in the summer months here and in Hawaii year round. Take care and best wishes with the repair. :cheers:

[vilant]

I was going to recharge my A/C myself. For $20 you can get yourself certified, to remove and recharge, it's an online course http://www.macsw.org/MACS/Section_609_Certification/MACS/Certification/Section_609_Certifcation.aspx?hkey=a4bf82fe-9db6-4507-8ddd-27fd9b9153f6.
Not sure what the rules are in Japan but here in the U.S. this is all you need to do it legally. There's other Youtube videos and online courses to learn more, along with your FSM. Why pay someone you don't know, when you could spend roughly the same amount and learn yourself? You can't trust anyone more than yourself. The most expensive part is the equipment, but you will own it and always have it.:cheers:

[Dynomite]

I was going to recharge my A/C myself. For $20 you can get yourself certified, to remove and recharge, it's an online course http://www.macsw.org/MACS/Section_609_Certification/MACS/Certification/Section_609_Certifcation.aspx?hkey=a4bf82fe-9db6-4507-8ddd-27fd9b9153f6.
Why pay someone you don't know, when you could spend roughly the same amount and learn yourself? You can't trust anyone more than yourself. The most expensive part is the equipment, but you will own it and always have it.:cheers:

Thank you Joe (vilant) :thumbsup:
That is some good stuff right there ;)

In my case I have several vehicles where the A/C is not working as well as it should and it is relatively expensive to have others do it. I guess that is why we do our own mechanic work on the LT5 :D

Also........ on the LT5 it is rare to find a mechanic familiar enough to know it will be done the right way.

You might be right and that is what I thought, but I admit I don't know diddly squat about air conditioning systems.

:D Me neither....but then again I did not know diddly squat about the LT5 a couple years ago (some say I still do not know diddly squat) :sign10:

[vilant]

Thank you vilant :thumbsup:
That is some good stuff right there ;)

In my case I have several vehicles where the A/C is not working as well as it should and it is relatively expensive to have others do it. I guess that is why we do our own mechanic work on the LT5 :D

Also........ on the LT5 it is rare to find a mechanic familiar enough to know it will be done the right way.



:D Me neither....but then again I did not know diddly squat about the LT5 a couple years ago (some say I still do not know diddly squat) :sign10:
Your welcome. And the good thing about it is I believe it's a lifetime cert.. And of course you will able to buy, recharge, and remove any refrigerant on any vehicle. And once you have the equipment you could always take an online course and have yourself certified in recharging and removing the refrigerant from your home condensing unit, too. With all the money you'll save maybe you could do a 600hp rebuild ;).

[Jagdpanzer]

(yep...with Headers attached) :p

Is there any special trick to doing that?
and what headers are you using?

[Dynomite]

Is there any special trick to doing that?
and what headers are you using?

Yep.....there is a trick or two ;)
The LT5 has to be tilted to the rear considerably and the LT5 has to be prevented from rolling from side to side.
Leave the Fuel Rails, Plenum, and Bell Housing OFF untill after the LT5 is installed in the ZR1.

SW Offroad Headers. As you know it is difficult to install headers with LT5 in the ZR1. With engine out I was able to install 14 of the 16 header bolts with locks (on each Header) in just a few minutes.

1. You definitely need a load leveler (to UNLEVEL or tilt the LT5 to the rear).
2. You CANNOT use the standard lift eyes for the LT5 because as you load UNLEVEL (Tilt engine to the rear) the engine rotates if you lift LT5 on diagonals.
3. You have to lift with nylon straps around Flywheel (rear) and around Harmonic Balancer (front). Actually around more stuff on front.
4. You have to remove the A/C Temperature sensor cover (passenger side firewall) and Wiper Motor (Drivers side firewall).
5. You DO NOT have to remove the hood and the ZR1 can sit on the level.

A/C Temp Sensor........................Wiper Motor.............Do NOT use standard Lift Eyes installing LT5 with Headers
http://i287.photobucket.com/albums/ll142/dynomite007/C%20Engine%20LT5/3854d085-53d6-4404-a022-19b831693bc3.jpghttp://i287.photobucket.com/albums/ll142/dynomite007/ZR1%20Maintenance/8ddc405c-0943-450c-9cec-07fb79829124.jpg
http://i287.photobucket.com/albums/ll142/dynomite007/C%20Engine%20LT5/bb9babbf-fe78-48d4-9719-8a19a11feab3.jpg

Installing Headers (http://forums.corvetteforum.com/c4-zr-1-discussion/3005470-tech-info-lt5-modifications-rebuild-tricks-500-hp-5.html#post1581825195)
Installing Engine In ZR1 (http://forums.corvetteforum.com/c4-zr-1-discussion/3005470-tech-info-lt5-modifications-rebuild-tricks-500-hp-5.html#post1581825199)
Lifting The LT5 (http://forums.corvetteforum.com/c4-zr-1-discussion/3005470-tech-info-lt5-modifications-rebuild-tricks-500-hp.html#post1580070571)

[HAWAIIZR-1]

I was going to recharge my A/C myself. For $20 you can get yourself certified, to remove and recharge, it's an online course http://www.macsw.org/MACS/Section_609_Certification/MACS/Certification/Section_609_Certifcation.aspx?hkey=a4bf82fe-9db6-4507-8ddd-27fd9b9153f6.
Not sure what the rules are in Japan but here in the U.S. this is all you need to do it legally. There's other Youtube videos and online courses to learn more, along with your FSM. Why pay someone you don't know, when you could spend roughly the same amount and learn yourself? You can't trust anyone more than yourself. The most expensive part is the equipment, but you will own it and always have it.:cheers:

Thanks for the info and something to consider. Some things are best left to experts too, but only if you can find the right shop/person to trust. :cheers:

[Dynomite]

Cliff,
Vacuum for an hour, then shut gauge manifold valves, turn off vacuum pump and monitor vacuum in system for evidence of any leaks. If none, you're set to charge with the amount of R-12 listed in the FSM. When you connect the can, make sure that you have the can upright and then loosen the fill hose at the manifold to purge the air, then retighten it. The can has to be upright to ensure that you get vapor, not liquid. Charge to the low(suction) side with can inverted until you cannot get any more Freon to flow into the system, then return can to upright position, start engine, leave doors open, switch climate control to auto and set to lowest temp setting. If you don't have enough pressure in the system for the A/c compressor to kick on, disconnect the pressure cycling switch and jump the two wires to energize the clutch. Add remaining Freon to the low side with can in upright position. You don't want any liquid Freon hitting the compressor, as that will damage it. Remember to shut the low side valve when changing cans and also re-purge the fill line. It doesn't take very much air/moisture in the system to seriously degrade performance.

The FSM lays it out very nicely. Shoot me a PM if you have any questions.

Jep

Ok.....hang on VetteVet ;)

I edited this post in accordance with the information provided by VetteVet in next post VetteVet How To Evacuate and Re-Charge A/C System on C4 ZR1 (http://zr1.net/forum/showthread.php?p=166412) just to make sure I understand.

I have a vacuum pump with an R12 fittings (actually two fittings) and a set of gauges (red and blue) with R12 adapters. I also have a new Accumulator/Drier (not installed yet as I assume I do not want to expose that to air). Have a few cans of R12 and a couple cans of R12 plus oil.

Vacuum the A/C System
1. The A/C connector on the passenger side with black cap (just inside of shock) is High Side.
2. The A/C connector on the Accumulator/Drier is the Low Side.
3. Connect gauges to the Vacuum Pump (yellow line center of Manifold).
4. Connect Low Side (Blue Line) to Accumulator/Drier connection.
5. Connect High Side (Red Line) to High Side connection just inside passenger wheel well (lower line on Evaporator Housing).
6. Open both High Side and Low Side Manifold Valves and turn on Vacuum Pump for 60 minutes.
7. Shut Manifold Valves (then shut OFF Vacuum Pump) and make sure Vacuum does not leak down indicating a System Leak.
8. If NO LEAKS, Install New Accumulator/Drier and repeat this process.

Charge the A/C System
1. With both Manifold Valves closed, hook up a can of R12 to the yellow middle hose (see Note #1 below).
2. Turn the can valve fully counterclockwise to open the valve.
3. With the can upright, crack the fitting on the yellow hose where it attaches to the gauge manifold to purge the air out of the hose, then retighten it.
4. You can now invert the can and crack the blue Low Side valve and charge until the pressure equalizes between the can and system (no more flow is felt or heard). Never open the Red High Side valve during the Freon Charging process.
5. Now start your car and set the climate control for Max cooling with blower on high. Ensure that the compressor clutch is engaged at this point (see Note #2 below). You can now charge the remainder of the first can with can in an upright position. Always charge with can upright when compressor is running.
6. Once the first can is in, (you'll know it's all in when you can shake the can and not feel any liquid sloshing in it) you can shut the low side valve and swap to the second can.
7. Remember to purge the yellow line again prior to charging.
8. Continue this until you have added the correct amount of Freon, per the FSM. Once the sytem is fully charged, shut off the compressor and allow High Side and Low Side pressures to equalize before disconnecting the gauge manifold from the system.
9. Once the manifold is disconnected, cap the high and low side fittings, reconnect the pressure cycling switch and you're done.

2 Stage Vacuum Pump.............................................. ....Manifold and Gauges
http://i287.photobucket.com/albums/ll142/dynomite007/C%20Engine%20LT5/415e1a74-bc06-42c6-828f-df14e479171e.jpghttp://i287.photobucket.com/albums/ll142/dynomite007/C%20Engine%20LT5/ced4b9a7-0a97-40b6-be76-c65a54548bac.jpg

Adapter Connections R134a to R12.................................R12 Can Connector and Gauge
http://i287.photobucket.com/albums/ll142/dynomite007/C%20Engine%20LT5/990f6935-bb25-4ccd-b7e1-7dd520595a90.jpghttp://i287.photobucket.com/albums/ll142/dynomite007/C%20Engine%20LT5/7eeee05d-566d-4d19-b316-facd32b4f3ce.jpg

Notes:
1. Prior to connecting the valve to the freon can, unscrew the valve stem fully(you will see the needle in the valve retract up into the body). Then screw the valve onto the can. Now turn the valve fully clockwise to puncture the can.
2. If the compressor clutch is not engaged, you will have to pull the connector on the pressure cycling valve in the low side line and jumper it. The compressor clutch should now engage.
3. The better you vacuum the system, the better it will perform. You won't hurt the vacuum pump if you want to let it run for 5 hours.
4. Always purge the air from the charging(yellow) line when you connect a can of Freon.
5. When the compressor is running, always charge to the low(blue) side with can upright.
6. NEVER, EVER open the high side valve when the compressor is running. That flimsy Freon can will not contain the pressure(can you say SHRAPNEL!!!). I've never done it and don't want to try.
7. If you follow these Notes, no harm will be done.
Thank you VetteVet (Jep) for the "How To" technical information including the Notes and thank you 4-cam for Accumulator/Drier replacement suggestion.

Cliff,

Remove caps on drier and install it just prior to vacuuming the system. The hose on the left side(blue) is low side. The hose on the right side(red) is high side. If you look at the evaporator housing, the line going into the bottom is the high pressure line. Follow that one back and you will find the high side fitting. The one on the accumulator/drier is the low side fitting. Vacuum the system with both valves open. Charge the system by opening the low side valve only. This is especially important as the pressure developed when the compressor is running will rupture the can of freon. NEVER, EVER open the high side valve with the compressor running.

If you don't have one, you'll need to pick up a freon can valve from your local auto parts store.

Hook up the yellow hose to the middle connection on the gauge manifold and to the vacuum pump. Vacuum the system and then shut manifold valves first, then shut off pump. Let the sytem sit long enough to ensure that vacuum is not dropping. If it is, you have to find and fix the leak(s). If not, then diconnect the hose from the pump and hook up the can valve to the yellow hose. Prior to connecting the valve to the freon can, unscrew the valve stem fully(you will see the needle in the valve retract up into the body). Then screw the valve onto the can. Now turn the valve fully clockwise to puncture the can, then turn fully counterclockwise to open the valve. With the can upright, crack the fitting on the yellow hose where it attaches to the gauge manifold to purge the air out of the hose, then retighten it. You can now invert the can and crack the blue low side valve and charge until the pressure equalizes between the can and system(no more flow is felt or heard). Now start your car and set the climate control for Max cooling with blower on high. Ensure that the compressor clutch is engaged at this point. If not, you will have to pull the connector on the pressure cycling valve in the low side line and jumper it. The compressor clutch should now engage and you can charge the remainder of the first can with it in an upright position. Always charge with can upright when compressor is running. Once the first can is in, (you'll know it's all in when you can shake the can and not feel any liquid sloshing in it) you can shut the low side valve and swap to the second can. Remember to purge the yellow line again prior to charging. Continue this until you have added the correct amount of Freon, per the FSM. Once the sytem is fully charged, shut off the compressor and allow high and low side pressures to equalize before disconnecting the gauge manifold from the system. Once the manifold is disconnected, cap the high and low side fittings, reconnect the pressure cycling switch and you're done.

Jep

No problem, Cliff. Glad to be of assistance.

Golden Rules:

1) The better you vacuum the system, the better it will perform. You won't hurt the vacuum pump if you want to let it run for 5 hours.
2) Always purge the air from the charging(yellow) line when you connect a can of Freon.
3) When the compressor is running, always charge to the low(blue) side with can upright.
4) NEVER, EVER open the high side valve when the compressor is running. That flimsy Freon can will not contain the pressure(can you say SHRAPNEL!!!). I've never done it and don't want to try.

If you follow these rules, no harm will be done.

Jep

[VetteVet]

Ok.....hang on VetteVet ;)

I have a vacuum pump with an R12 fittings (actually two fittings one looks a bit larger) and a set of gauges (red and blue) with R12 adapters. I also have a new Drier (not installed yet as I assume I do not want to expose that to air).
1. Have a few cans of R12 and a couple cans of R12 plus oil. The A/C connector on the passenger side with black cap (just inside of shock) must be low side?
2. Where is the High Side A/C connector (is it on the Drier?) and do I have to connect gauges to both? I connect Vacuum Pump to low side connector or to center connector on gauge while gauge is connected to Low Side as well as High Side?
3. Do I Vacuum the Low Side as well as the High Side?
4. When do I install the New Drier?

More questions to follow if you do not mind.

http://i287.photobucket.com/albums/ll142/dynomite007/C%20Engine%20LT5/415e1a74-bc06-42c6-828f-df14e479171e.jpghttp://i287.photobucket.com/albums/ll142/dynomite007/C%20Engine%20LT5/28ba6e70-56ea-497e-9a94-7c2e6be619c3.jpg
http://i.ebayimg.com/t/R12-to-R134a-Flex-Hose-Adapter-Set-Use-w-R134a-Gauges-/03/!B,kqGm!!mk~$(KGrHqQH-CYEqvCGYuhlBKsDCVSJRQ~~_12.JPG

Cliff,

Remove caps on drier and install it just prior to vacuuming the system. The hose on the left side(blue) is low side. The hose on the right side(red) is high side. If you look at the evaporator housing, the line going into the bottom is the high pressure line. Follow that one back and you will find the high side fitting. The one on the accumulator/drier is the low side fitting. Vacuum the system with both valves open. Charge the system by opening the low side valve only. This is especially important as the pressure developed when the compressor is running will rupture the can of freon. NEVER, EVER open the high side valve with the compressor running.

If you don't have one, you'll need to pick up a freon can valve from your local auto parts store.

Hook up the yellow hose to the middle connection on the gauge manifold and to the vacuum pump. Vacuum the system and then shut manifold valves first, then shut off pump. Let the sytem sit long enough to ensure that vacuum is not dropping. If it is, you have to find and fix the leak(s). If not, then diconnect the hose from the pump and hook up the can valve to the yellow hose. Prior to connecting the valve to the freon can, unscrew the valve stem fully(you will see the needle in the valve retract up into the body). Then screw the valve onto the can. Now turn the valve fully clockwise to puncture the can, then turn fully counterclockwise to open the valve. With the can upright, crack the fitting on the yellow hose where it attaches to the gauge manifold to purge the air out of the hose, then retighten it. You can now invert the can and crack the blue low side valve and charge until the pressure equalizes between the can and system(no more flow is felt or heard). Now start your car and set the climate control for Max cooling with blower on high. Ensure that the compressor clutch is engaged at this point. If not, you will have to pull the connector on the pressure cycling valve in the low side line and jumper it. The compressor clutch should now engage and you can charge the remainder of the first can with it in an upright position. Always charge with can upright when compressor is running. Once the first can is in, (you'll know it's all in when you can shake the can and not feel any liquid sloshing in it) you can shut the low side valve and swap to the second can. Remember to purge the yellow line again prior to charging. Continue this until you have added the correct amount of Freon, per the FSM. Once the sytem is fully charged, shut off the compressor and allow high and low side pressures to equalize before disconnecting the gauge manifold from the system. Once the manifold is disconnected, cap the high and low side fittings, reconnect the pressure cycling switch and you're done.


Jep

[Dynomite]

Cliff,

Remove caps on drier and install it just prior to vacuuming the system. The hose on the left side(blue) is low side. The hose on the right side(red) is high side. If you look at the evaporator housing, the line going into the bottom is the high pressure line. Follow that one back and you will find the high side fitting. The one on the accumulator/drier is the low side fitting. Vacuum the system with both valves open. Charge the system by opening the low side valve only. This is especially important as the pressure developed when the compressor is running will rupture the can of freon. NEVER, EVER open the high side valve with the compressor running.

If you don't have one, you'll need to pick up a freon can valve from your local auto parts store.

Hook up the yellow hose to the middle connection on the gauge manifold and to the vacuum pump. Vacuum the system and then shut manifold valves first, then shut off pump. Let the sytem sit long enough to ensure that vacuum is not dropping. If it is, you have to find and fix the leak(s). If not, then diconnect the hose from the pump and hook up the can valve to the yellow hose. Prior to connecting the valve to the freon can, unscrew the valve stem fully(you will see the needle in the valve retract up into the body). Then screw the valve onto the can. Now turn the valve fully clockwise to puncture the can, then turn fully counterclockwise to open the valve. With the can upright, crack the fitting on the yellow hose where it attaches to the gauge manifold to purge the air out of the hose, then retighten it. You can now invert the can and crack the blue low side valve and charge until the pressure equalizes between the can and system(no more flow is felt or heard). Now start your car and set the climate control for Max cooling with blower on high. Ensure that the compressor clutch is engaged at this point. If not, you will have to pull the connector on the pressure cycling valve in the low side line and jumper it. The compressor clutch should now engage and you can charge the remainder of the first can with it in an upright position. Always charge with can upright when compressor is running. Once the first can is in, (you'll know it's all in when you can shake the can and not feel any liquid sloshing in it) you can shut the low side valve and swap to the second can. Remember to purge the yellow line again prior to charging. Continue this until you have added the correct amount of Freon, per the FSM. Once the sytem is fully charged, shut off the compressor and allow high and low side pressures to equalize before disconnecting the gauge manifold from the system. Once the manifold is disconnected, cap the high and low side fittings, reconnect the pressure cycling switch and you're done.

Jep

Jep....I can do this :cheers:

Nice write up....appreciate it :thumbsup:
I put all your information together in a single post if that is OK with you and if I understand the technical information correctly.......Evacuation and Re-Charging C4 ZR1 A/C System (http://zr1.net/forum/showthread.php?p=166403)
Jep......... really appreciate you taking your time to explain this for us :handshak:

I will go slow and practice vacuuming A/C and checking for leaks first. I think before I install new drier. Then vacuum the A/C system a second time after I know there are no leaks.

The 91' ZR-1 is running sooooo good it is unbelievable :cheers:
With ALL the eliminated systems and with TB coolant removed LT5 Eliminated Systems (http://forums.corvetteforum.com/c4-zr-1-discussion/2942569-tech-info-lt5-eliminated-systems.html).

The new technique of Eliminating Air from the coolant system worked perfectly for this refill of coolant Filling With Coolant and the Air Locked Water Pump (http://forums.corvetteforum.com/c4-zr-1-discussion/3005470-tech-info-lt5-modifications-rebuild-tricks-500-hp-5.html#post1581827089).

Cliff

[Kevin]

I need to get my ac replaced in the spring when the car comes out of storage, wish I had someone local to help me but since I don't, off to the dealer it goes

[VetteVet]

Jep....I can do this :cheers:

Nice write up....appreciate it :thumbsup:
I put all your information together in a single post if that is OK with you and if I understand the technical information correctly.......Evacuation and Re-Charging C4 ZR1 A/C System (http://zr1.net/forum/showthread.php?p=166403)
Jep......... really appreciate you taking your time to explain this for us :handshak:

I will go slow and practice vacuuming A/C and checking for leaks first. I think before I install new drier. Then vacuum the A/C system a second time after I know there are no leaks.

The 91' ZR-1 is running sooooo good it is unbelievable :cheers:
With ALL the eliminated systems and with TB coolant removed LT5 Eliminated Systems (http://forums.corvetteforum.com/c4-zr-1-discussion/2942569-tech-info-lt5-eliminated-systems.html).

The new technique of Eliminating Air from the coolant system worked perfectly for this refill of coolant Filling With Coolant and the Air Locked Water Pump (http://forums.corvetteforum.com/c4-zr-1-discussion/3005470-tech-info-lt5-modifications-rebuild-tricks-500-hp-5.html#post1581827089).

Cliff

No problem, Cliff. Glad to be of assistance.

Golden Rules:
1) The better you vacuum the system, the better it will perform. You won't hurt the vacuum pump if you want to let it run for 5 hours.
2) Always purge the air from the charging(yellow) line when you connect a can of Freon.
3) When the compressor is running, always charge to the low(blue) side with can upright.
4) NEVER, EVER open the high side valve when the compressor is running. That flimsy Freon can will not contain the pressure(can you say SHRAPNEL!!!). I've never done it and don't want to try.

If you follow these rules, no harm will be done.

Jep

[scottfab]

This is great stuff.
To all who have contributed to this list THANKS!
I've been doing almost right for several decades.
The part I wasn't doing is in blue.
I made a few corrections to the text.
Printing this and putting it with the equipment.

Vacuum the A/C System
1. The A/C connector on the passenger side with black cap (just inside of shock) is High Side.
2. The A/C connector on the Accumulator/Drier is the Low Side.
3. Connect gauges to the Vacuum Pump (yellow line center of Manifold).
4. Connect Low Side (Blue Line) to Accumulator/Drier connection.
5. Connect High Side (Red Line) to High Side connection just inside passenger wheel well (lower line on Evaporator Housing).
6. Open both High Side and Low Side Manifold Valves and turn on Vacuum Pump for 60 minutes.
7. Shut Manifold Valves (then shut OFF Vacuum Pump) and make sure Vacuum does not leak down indicating a System Leak.
8. If NO LEAKS, Install New Accumulator/Drier and repeat this process.

Charge the A/C System
1. With both Manifold Valves closed, hook up a can of R12 to the yellow middle hose (see Note #1 below).
2. Turn the can valve fully counterclockwise to open the valve.
3. With the can upright, crack the fitting on the yellow hose where it attaches to the gauge manifold to purge the air out of the hose, then re-tighten it.
4. You can now invert the can and crack the blue Low Side valve and charge until the pressure equalizes between the can and system (no more flow is felt or heard). Never open the Red High Side valve during the Freon Charging process.
5. Now start your car and set the climate control for Max cooling with blower on high. Ensure that the compressor clutch is engaged at this point (see Note #2 below). You can now charge the remainder of the first can with can in an upright position. Always charge with can upright when compressor is running.
6. Once the first can is in, (you'll know it's all in when you can shake the can and not feel any liquid sloshing in it) you can shut the low side valve and swap to the second can.
7. Remember to purge the yellow line again prior to charging.
8. Continue this until you have added the correct amount of Freon, per the FSM. Once the system is fully charged, shut off the compressor and allow High Side and Low Side pressures to equalize before disconnecting the gauge manifold from the system.
9. Once the manifold is disconnected, cap the high and low side fittings, reconnect the pressure cycling switch and you're done.

2 Stage Vacuum Pump
Manifold and Gauges
http://i287.photobucket.com/albums/ll142/dynomite007/C%20Engine%20LT5/415e1a74-bc06-42c6-828f-df14e479171e.jpghttp://i287.photobucket.com/albums/ll142/dynomite007/C%20Engine%20LT5/ced4b9a7-0a97-40b6-be76-c65a54548bac.jpg

Adapter Connections R134a to R12
.R12 Can Connector and Gauge
http://i287.photobucket.com/albums/ll142/dynomite007/C%20Engine%20LT5/990f6935-bb25-4ccd-b7e1-7dd520595a90.jpghttp://i287.photobucket.com/albums/ll142/dynomite007/C%20Engine%20LT5/7eeee05d-566d-4d19-b316-facd32b4f3ce.jpg

Notes:
1. Prior to connecting the valve to the freon can, unscrew the valve stem fully(you will see the needle in the valve retract up into the body). Then screw the valve onto the can. Now turn the valve fully clockwise to puncture the can.
2. If the compressor clutch is not engaged, you will have to pull the connector on the pressure cycling valve in the low side line and jumper it. The compressor clutch should now engage.

[scottfab]

VetteVet is the contributor of All the Technical information. 4-cam recommended Accumulator/Drier replacement.

Yes, got that from reading the thread.

I have no idea what "corrections" you made to the text?

I didn't think the corrections important enough to point out. It would seem unnecessarily rude. One correction could be instructive. The use of red in text defeats it purpose when printed in black and white. It shows up as light gray. I removed all unnecessary text embellishments in order to make it more readable. Some embellishments are good. Too many cause distraction and readability issues. This comes from over 20 years of exposure to and working with professional technical writers. But each to their own if it is their own.

The description you printed out is not yet complete as there are more photos and details coming and VetteVet may add more technical input.

Complete enough to be useful as is.

All those Details will be/are now in -Solutions- Evacuation and Re-Charging C4 ZR1 A/C System (http://zr1.net/forum/showthread.php?p=166403) with thanks, appreciation and credit to VetteVet (Jep) and 4-cam noted :thumbsup:

Yes, got that from reading the thread too.

There are two related "How Tos" as these caused the loss of an evaporator which started this thread (Always tie back/secure the hoses to the A/C Evaporator when setting aside but not disconnecting the A/C compressor) :D

Think that was in the thread also.

1. Eliminated Systems.
Eliminated systems with TB coolant removed LT5 Eliminated Systems (http://forums.corvetteforum.com/c4-zr-1-discussion/2942569-tech-info-lt5-eliminated-systems.html).

Was in the thread as well.

[QUOTE=Dynomite;166506]2. Coolant Refill.
The new technique of Eliminating Air from the coolant system worked perfectly for this refill of coolant Filling With Coolant and the Air Locked Water Pump (http://forums.corvetteforum.com/c4-zr-1-discussion/3005470-tech-info-lt5-modifications-rebuild-tricks-500-hp-5.html#post1581827089).

That's nice. I simply disconnect the driver side hose on the TB and point it up. The air all leaves from there as you fill the fluid. refilling the reservoir after one engine use, after it cools down, requires very little coolant.

I talked with Marc Haibeck and he uses a similar technique of getting the air out (air locked Water Pump) using compressed air at certain times during the Coolant Refill. Ask Marc for Details Haibeck Automotive Technology (http://www.zr1specialist.com/).

Cliff

Thanks but I don't think I'll be bothering him with such things. It would be an unnecessary distraction for him.

[Dynomite]

No problem, Cliff. Glad to be of assistance.

Golden Rules:
1) The better you vacuum the system, the better it will perform. You won't hurt the vacuum pump if you want to let it run for 5 hours.
2) Always purge the air from the charging(yellow) line when you connect a can of Freon.
3) When the compressor is running, always charge to the low(blue) side with can upright.
4) NEVER, EVER open the high side valve when the compressor is running. That flimsy Freon can will not contain the pressure(can you say SHRAPNEL!!!). I've never done it and don't want to try.

If you follow these rules, no harm will be done.

Jep

Hi Jep........I added your "Golden Rules" as Notes .......Evacuation and Re-Charging C4 ZR1 A/C System (http://zr1.net/forum/showthread.php?p=166403) ;)

I will let you know how it goes and post up after the first Evacuation. The first A/C System Evacuation to check for A/C System leaks. Then I will add the New Accumulator/Drier and Evacuate the A/C System a second time leaving the vacuum on for over an hour as you suggest....

This is getting exciting.....it is soooo much more fun knowing one can do these maintenance items themselves. And just have to mention........you Jep are a great teacher :handshak:

Contributions like yours are what makes this Forum Exciting for guys like myself who enjoy the Mechanics and Technical aspects of the ZR-1 (LT5) and Corvette (L98) as much as driving them. Makes driving them all that much more fun :thumbsup:

Note:
1. When you remove the LT5 from the ZR-1 by first removing the Plenum and A/C Compressor, before setting the A/C compressor aside on Drivers side wheel well.......secure the A/C lines going to the Passenger Side Evaporator so they do not move and break at the Evaporator.

Cliff

[Mystic ZR-1]

This would be a good time to ask how to switch over to 134a.
R12 is hard to get and $$$
Thanks!

[VetteVet]

This would be a good time to ask how to switch over to 134a.
R12 is hard to get and $$$
Thanks!

This can be a tricky subject with lots of conflicting info available. Here is a "Cliff's Notes" type of guide:

http://autoacrepairs.com/134aConversion.htm

If you want to convert, I would recommend taking your car to a reputable shop that specializes in automotive AC repairs and pay them to do it. Once the conversion is done, then you can do your own maintenance and repairs from that point forward. Just bear in mind that there is a right way and a "quick and dirty" way. Make sure that the shop you are dealing with knows what they are doing. Expect your AC performance to take a hit, as R134a won't cool as well as R12.

Jep

[scottfab]

This would be a good time to ask how to switch over to 134a.
R12 is hard to get and $$$
Thanks!

I did the conversion in 01.
It cost me about $250 for everything. Most of that ($180)
was for the rebuilt compressor and clutch assembly.
The dryer was surprisingly cheap.
I didn't put a label on the car stating R134a.
I did not inspect the orifice I just replaced it. (cheap)
I did not leak test it, just filled it and it worked.

After all was done, I loaded up on R134a cans at $4.99 ea.
They're up to about $10 now I see.

[Dynomite]

I am looking for a complete electrical schematic of the A/C system on a 90' and 91' (I assume they are the same) ZR-1.

[vilant]

I am looking for a complete electrical schematic of the A/C system on a 90' and 91' (I assume they are the same) ZR-1.
I assume you have electronic control (there is manual). If this helps let me know, if not, I'll delete the post.:cheers:
http://www.zr1.net/forum/picture.php?albumid=241&pictureid=2087
http://www.zr1.net/forum/picture.php?albumid=241&pictureid=2088
http://www.zr1.net/forum/picture.php?albumid=241&pictureid=2092
http://www.zr1.net/forum/picture.php?albumid=241&pictureid=2093

[vilant]

Whoops, pages out of order. sorry.
http://www.zr1.net/forum/picture.php?albumid=241&pictureid=2089
http://www.zr1.net/forum/picture.php?albumid=241&pictureid=2090
http://www.zr1.net/forum/picture.php?albumid=241&pictureid=2091

[-=Jeff=-]

I was going to recharge my A/C myself. For $20 you can get yourself certified, to remove and recharge, it's an online course http://www.macsw.org/MACS/Section_609_Certification/MACS/Certification/Section_609_Certifcation.aspx?hkey=a4bf82fe-9db6-4507-8ddd-27fd9b9153f6.
Not sure what the rules are in Japan but here in the U.S. this is all you need to do it legally. There's other Youtube videos and online courses to learn more, along with your FSM. Why pay someone you don't know, when you could spend roughly the same amount and learn yourself? You can't trust anyone more than yourself. The most expensive part is the equipment, but you will own it and always have it.:cheers:


I took my 609 Cert 2 years ago.. It is also open book at least when I took it.. fairly easy test to take

[Dynomite]

Whoops, pages out of order. sorry.



Joe.....you are DAMAN.....thanks....I shall study this. Appreciate the photo copies :thumbsup: :thumbsup:
I am looking for that 25 amp A/C fuse on main fuse block? I have no voltage at the pressure cycling switch so I hot wired the compressor clutch which engaged fine.

Cliff

[vilant]

YW. If you need the fuse block details, let me know.

[Dynomite]

YW. If you need the fuse block details, let me know.
Ya...where is that A/C 25 amp fuse?
Or maybe I should ask were is that Main Fuse Block ;)

:handshak:

[scottfab]

Ya...where is that A/C 25 amp fuse?
Or maybe I should ask were is that Main Fuse Block ;)

:handshak:

Main Fuse Block 8A-11-0
Sad I know that without looking :mad:

[Dynomite]

Main Fuse Block 8A-11-0
Sad I know that without looking :mad:

Hi: That is NOT sad......That is Happy ;)
So where is that fuse block on the car and is there a 25 amp A/C Fuse in that block?

I am presently looking at the A/C Clutch Relay (VetteVet on the phone explaining it is second relay to right of steering Column) :thumbsup:
I am checking to make sure I have HOT at the relay with engine running. And then Hot after the relay. I have no voltage at the 10 amp A/C fuse on right passenger fuse panel. No voltage at A/C High Pressure Cut out switch or A/C Pressure Cycling switch.

This all happened when I was poking around with a hot wire and you know how that goes :sign10:
I am soooooo close......:D

Cliff

[scottfab]

I am not where I can look at the 8A manual or the car.
but if memory serves the fuses are labeled.

Hi: That is NOT sad......That is Happy ;)
So where is that fuse block on the car and is there a 25 amp A/C Fuse in that block?

I am presently looking at the A/C Clutch Relay (VetteVet on the phone explaining it is second relay to right of steering Column) :thumbsup:
I am checking to make sure I have HOT at the relay with engine running. And then Hot after the relay. I have no voltage at the 10 amp A/C fuse on right passenger fuse panel. No voltage at A/C High Pressure Cut out switch or A/C Pressure Cycling switch.

This all happened when I was poking around with a hot wire and you know how that goes :sign10:
I am soooooo close......:D

Cliff

[vilant]

Here's the fuse block on the passenger side. The 2 fuses are 15A CTSY fuse and 25A A/C fuse. The clutch relay should be fed from 25A. Not sure why you have a 10A for CTSY (if that's what you're talking about).
http://www.zr1.net/forum/picture.php?albumid=241&pictureid=2094

[Dynomite]

Here's the fuse block on the passenger side. The 2 fuses are 15A CTSY fuse and 25A A/C fuse. The clutch relay should be fed from 25A. Not sure why you have a 10A for CTSY (if that's what you're talking about).


The fans (heater/air) do not work either as they stopped at the same time I lost power to the Pressure Cycling Switch.

I think everything else is working as far as I know. The Heater Controller on the dash I prolly messed up by jumping the Pressure Cycling Switch too many times in succession ;)

I have an extra Heater Controller from a 90' Corvette that looks identical...which I may just switch as an experiment.
That switch should take an hour and then I can eliminate the Heater Controller as the issue. I will take a picture tomorrow of that experiment.

The lesson learned will be.....do NOT Jumber the Pressure Cycling Switch to get the compressor working but rather hot wire the compressor at the Pressure Cycling Switch connector (12 volts directly from battery to A/C Compressor) after determining which lead at the switch goes to the A/C Compressor.

I was going to check the A/C Clutch relay but thinking on it....that would not effect the Heater/Air Fans.
Is your schematic a 90'?

This is a 91' passenger side fuse block...I have a 15 amp for CTSY and a 10 amp fuse there for AC
http://i287.photobucket.com/albums/ll142/dynomite007/C%20Engine%20LT5/Fuses.jpg

[vilant]

All information and pics are from the 1990 Section 8A Electrical Diagnosis Supplement. I can't say what is needed for anything after 1990 ( but I assume 91 should be the same), but on a 1990 there should be a 25A fuse, not 10A on the A/C fuse space.
P.S. If you look on pg 8A-66-1 of the pics I gave you, you'll see there's a 5A A/C underhood fuse on the line that gives input to the heater/ AC programmer from the output of the blower power module. There is also a fusible link that feeds the blower control module. If the link is completely blown, the blower will not work (I'm assuming the heater programmer will not work properly without input(voltage) from the blower power module output, which is protected by the 5A fuse).

[Dynomite]

All information and pics are from the 1990 Section 8A Electrical Diagnosis Supplement. I can't say what is needed for anything after 1990 ( but I assume 91 should be the same), but on a 1990 there should be a 25A fuse, not 10A on the A/C fuse space.

P.S. If you look on pg 8A-66-1 of the pics I gave you, you'll see there's a 5A A/C underhood fuse on the line that gives input to the heater/ AC programmer from the output of the blower power module. There is also a fusible link that feeds the blower control module. If the link is completely blown, the blower will not work (I'm assuming the heater programmer will not work properly without input (voltage) from the blower power module output, which is protected by the 5A fuse).

5 amp A/C fuse is in fine shape.....Heater Controller was switched with no effect.
I now have power to the A/C Pressure Cycling Switch.
No fan response on Heat or A/C. I have not located the fusible link.

I took a peak at the Fan Wire Harness and in the process am re-routing the HVAC Wire Harness to a better location.

Guess what.....:D
When I installed the engine there was ONE SINGLE ground wire not connected up from Wire Harness at rear of engine.....Guess which one :sign10:

I connected that ground wire through my ohm meter to the black wire on fan connection ....and.....zero ohms :D
http://i287.photobucket.com/albums/ll142/dynomite007/Maintenance%20ZR1/827efb31-8861-4a13-abf2-d7e3f482cefa.jpg

[vilant]

Glad you got it figured out. I didn't notice the number 10, written below the A/C fuse, the first time I looked at the pic. I looked at my A/C fuse space and it has 25 below it. Guess that's something else that's different on 90's then the later year models. Which probably means the drawings are only relevant to a 90, nothing later (probably no fusible link either, on later models). Would you like me delete those drawings?:cheers:

[Dynomite]

Glad you got it figured out. I didn't notice the number 10, written below the A/C fuse, the first time I looked at the pic. I looked at my A/C fuse space and it has 25 below it. Guess that's something else that's different on 90's then the later year models. Which probably means the drawings are only relevant to a 90, nothing later (probably no fusible link either, on later models). Would you like me delete those drawings?:cheers:

Absolutely not (do not delete the drawings).....that is a great reference and if not exact...very close. Even the color wires. Thanks......and yes....there are differences here and there between the 90' and 91'. Since I have both, your drawings are very relevant :handshak:

Fans are now working but had to attach that fan ground wire to rear Plenum bolt where I can get at it :D

Cliff