Help please with clutch master cylinder

[salvatore1]

I replaced the clutch master cylinder today. Took my whole damn day - total PITA. Now here's the wonderful part - it looks to be leaking from where the plastic reservoir (where it meets the metal housing). This thing looks flimsy to begin with and there seems to be a certain amount of play in that area. I notice the old unit had some type of zip tie wrapped around it - this one does not. The unit I bought was a Rhino Pac from rockautoparts.

Bottom line - please do not tell me I need to replace this thing again because I may end up hurting someone or something.

[Kb7tif]

If your old one wasnt leaking why not swap out the rubber seals from the old master?

[tomtom72]

Oh jez, I feel your pain...as some famous person once said. Check out this link from our mother-ship.
http://www.zr1netregistry.com/ZR1_mastercylinder.htm

Call RockAuto & tell them you have a defective part. The clutch M/C's had issues with the seal for the reservior, and the formed lip on the reservior where the seal is mounted. The leak could be from either issue, or both. I had one like that. The picts may still be up on Bill's site. You may want to check over there also. zfdoc.com.

I felt that the clutch M/C's r&r wasn't that bad. You did take off the gill panel and remove the battery right? You need a 13mm swivel socket and a coupla different extension lenghts and a 14mm line wrench for the line. I think it takes longer to put the car up on stands than it does to r&r the hydraulic stuff. The pedal rod clip was tough the first time, but after a few I could stay outside the car and just reach up and r&r the clip. The hose mount is a pia, almost can't even see it thru all the "stuff".

:cheers:
Tom

[salvatore1]

Oh jez, I feel your pain...as some famous person once said. Check out this link from our mother-ship.
http://www.zr1netregistry.com/ZR1_mastercylinder.htm

Call RockAuto & tell them you have a defective part. The clutch M/C's had issues with the seal for the reservior, and the formed lip on the reservior where the seal is mounted. The leak could be from either issue, or both. I had one like that. The picts may still be up on Bill's site. You may want to check over there also. zfdoc.com.

I felt that the clutch M/C's r&r wasn't that bad. You did take off the gill panel and remove the battery right? You need a 13mm swivel socket and a coupla different extension lenghts and a 14mm line wrench for the line. I think it takes longer to put the car up on stands than it does to r&r the hydraulic stuff. The pedal rod clip was tough the first time, but after a few I could stay outside the car and just reach up and r&r the clip. The hose mount is a pia, almost can't even see it thru all the "stuff".

:cheers:
Tom


Hey Tom,

In my opinion, the MC was 10 times harder to install than the SC - took me 4 hours for the master and about 1 for the slave. I did remove the side panel and battery, but it was a tight fit getting past the wiring harness and cables (but I was very careful).


Now what's weird is now I'm not seeing any fluid around that base as before - could I have spiled some fluid without realizing it? But why does that base seem so flimsy - are they all like that?

It does still feel like there's still a bit of air in the hydraulics - should I just leave it alone and drive it as is until the air works itself out?


Thanks again,
Sal

[tomtom72]

Sal, If you feel that there is still some air in the system I would try to get it out before driving the car. What makes you suspect air in the system?

Oh, I wasn't throwing rocks at you on this job. It's just that my system dumped during the height of the quality control issues on the replacements awhile back....I did four of each and after the second one I could do both in about an hour & a half including putting the car up on stands.

I eventually bought a phoenix injector tool to do the reverse bleed from the slave up to the M/C. I can lend you my phoenix tool if you feel you need it?

Check out Bill site for the skinny on what went on and as it seems to me what is still going on with the quality issues. Plus I believe he has a "how to" on the r&r and bleeding. http://www.zfdoc.com/

Did you try to use the factory method in the FSM to do the bleed? Usually that works best if you pre bleed the s/s & m/c before the install. They don't say that in the FSM, but after my oddessy I found bench bleeding is a must. JMHO:redface:

:cheers:
Tom

[salvatore1]

Sal, If you feel that there is still some air in the system I would try to get it out before driving the car. What makes you suspect air in the system?

Oh, I wasn't throwing rocks at you on this job. It's just that my system dumped during the height of the quality control issues on the replacements awhile back....I did four of each and after the second one I could do both in about an hour & a half including putting the car up on stands.

I eventually bought a phoenix injector tool to do the reverse bleed from the slave up to the M/C. I can lend you my phoenix tool if you feel you need it?

Check out Bill site for the skinny on what went on and as it seems to me what is still going on with the quality issues. Plus I believe he has a "how to" on the r&r and bleeding. http://www.zfdoc.com/

Did you try to use the factory method in the FSM to do the bleed? Usually that works best if you pre bleed the s/s & m/c before the install. They don't say that in the FSM, but after my oddessy I found bench bleeding is a must. JMHO:redface:

:cheers:
Tom

Tom,

I think it needs to be bled more because the pedal feels a little spongy and going into 1st at a dead stop (with clutch to the floor) I still feel the car move just a tad (barely, but I can feel it). Also now it looks like it is still leaking a tiny bit of fluid around the base of the reservoir (especially if you push down on it)...would this leak cause air in the lines?

Dont worry about critiquing my repair job. This is no place for egos (mine or anyone elses) and I'm ever so appreciative for the tips. I'm the last one to call myself an expert at anything, but I do have a very good knack for mucking my way though the unknown.

About this phoenix injector - is this one of those "one man bleeders" I've seen at the auto parts stores (with a pump/squeeze handle and gauge)? I was bleeding it the old fashion way with my son in the drivers seat pushing the clutch in and holding it while I crack the bleeder screw on the slave...PITA!!!!! If you have a tool that would make this work for me I would love to borrow it if possible.

Thanks again
Sal

[QB93Z]

Sal,

You should be able to get all the air out of the clutch hydraulics system by pumping the pedal. I have done it recently on three different ZR-1's.

Things to look for:

As best you can, check that the hydraulic line from the slave cylinder to the master cylinder runs up hill without any kinks or sharp bends, and is not pinched.

When your assistant is pumping the clutch pedal to bleed the system, remove the fluid reservoir cap, and the black bellows shaped seal that is under the cap.

Watch the reservoir with a flash light. If you see small bubbles rising up in the liquid, have your assistant keep pumping. When the bubbles stop, the air is gone.

Good luck

Jim

[tomtom72]

Sal,

Usually I don't like to say this but somethings is wrong. If you're going into 1st from a dead stop....it shouldn't feel like you just dropped an auto trans into gear. Air is most likely the issue, Or the slave is also deffective...I hope not. I don't like that fluid at the reservior base either, it shouldn't be there and yes the thing is flimsey as all heck...mine sways in the breeze but doesn't have any fluid peeking out at the base. I'm using a cast M/C also.

One other possibility is that IF you put the parts in dry and didn't pre-bleed (bench-bleeding ) them, then the slave piston ran out of finished bore & got hurt....OR, as was the case with the original Q/Control issues there is still junk after machining left inside the parts. Okay enough of that speculating.

Bleeding: normally I'd say the FSM procedure is okay. After all the BS I went thru I figured it was me and not the parts. Soooo, I bought a pheonix gun. It's a reverse bleeder. Hook is at the slave bleeder and it pumps up to the M/C, chaseing the air as the system fills. I always bench bleed my stuff, along about the third set, prior to install.

Did you check out Bill's site? You could shoot him an e-mail and he will answer. I hate to say this. At the point you're at, all new parts installed & no usefull pedal? I would maybe give bleeding as per Jim's description another go. If it doen't pan out, it's time for new parts as there is an air leak in what you have now. Sorry to be the bearer of bad news. It sure looks like to me that GM et al didn't do much about the "spillage" issues, or at least not all of them. Oh, forgot this tid bit. No offense intended here, but you are NOT bleeding the system using the bleeder valve on the slave are you? You know you can't use that valve if the slave is installed, right? The slave has to dangle by the line if you want to do the bleed that way. Which to me is a royal PIA. That's another reason I spent $125 on the pheonix gun.

:cheers:
Tom

[salvatore1]

Sal,

Usually I don't like to say this but somethings is wrong. If you're going into 1st from a dead stop....it shouldn't feel like you just dropped an auto trans into gear. Air is most likely the issue, Or the slave is also deffective...I hope not. I don't like that fluid at the reservior base either, it shouldn't be there and yes the thing is flimsey as all heck...mine sways in the breeze but doesn't have any fluid peeking out at the base. I'm using a cast M/C also.

One other possibility is that IF you put the parts in dry and didn't pre-bleed (bench-bleeding ) them, then the slave piston ran out of finished bore & got hurt....OR, as was the case with the original Q/Control issues there is still junk after machining left inside the parts. Okay enough of that speculating.

Bleeding: normally I'd say the FSM procedure is okay. After all the BS I went thru I figured it was me and not the parts. Soooo, I bought a pheonix gun. It's a reverse bleeder. Hook is at the slave bleeder and it pumps up to the M/C, chaseing the air as the system fills. I always bench bleed my stuff, along about the third set, prior to install.

Did you check out Bill's site? You could shoot him an e-mail and he will answer. I hate to say this. At the point you're at, all new parts installed & no usefull pedal? I would maybe give bleeding as per Jim's description another go. If it doen't pan out, it's time for new parts as there is an air leak in what you have now. Sorry to be the bearer of bad news. It sure looks like to me that GM et al didn't do much about the "spillage" issues, or at least not all of them. Oh, forgot this tid bit. No offense intended here, but you are NOT bleeding the system using the bleeder valve on the slave are you? You know you can't use that valve if the slave is installed, right? The slave has to dangle by the line if you want to do the bleed that way. Which to me is a royal PIA. That's another reason I spent $125 on the pheonix gun.

:cheers:
Tom


Tom,

I'm going to try reverse bleeding the system with something like this http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=92474

Also, there is a very very small amount of fluid at the base of the reservoir that only shows up when you push down on it - is this still bad enough to replace. Although I am anal about spending good money for a part that still is not 100% perfect, I just cannot stand the thought of replacing the thing again.

I had one other question though. I notice there's a SPACER between the firewall and the master cylinder mount (about 1/4 thick). Should this stay even though my new cast iron MC mount is a little thicker (currently I have the spacer in place).


Sal

[Kb7tif]

Heres how I did it and worked 100%.
Open up the master so you can see the fluid,Roll the drivers window down use a baseball bat or something to press the clutch peddle very sightly about 1 or 2 inches, keep it there Small bubbles with surface in the master, release and do this several times. Until no more bubble come up. You should be 90%. peddle the clutch down with the foot several Times slowly. You should have a rock hard peddle. If you need to reverse bleed this there is trouble.
These systems are quite good, and should self bleed most air out in normal use. Good luck

[QB93Z]

Sal,

The problem that I see with pressure bleeders like the one you linked to is that you have to make sure that the line you connect to the bleeder port on the slave cylinder is free of air when you start or you are introducing more air into the system.

Also, when you pressure bleed from the bottom (slave cylinder), you will overflow the reservoir and spill fluid down the sides of the reservoir to the area you are concerned about. If you wrap a rag around the reservoir you may be able to catch the overflow.

Jim

[tomtom72]

Tom,

I'm going to try reverse bleeding the system with something like this http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=92474

Also, there is a very very small amount of fluid at the base of the reservoir that only shows up when you push down on it - is this still bad enough to replace. Although I am anal about spending good money for a part that still is not 100% perfect, I just cannot stand the thought of replacing the thing again.

I had one other question though. I notice there's a SPACER between the firewall and the master cylinder mount (about 1/4 thick). Should this stay even though my new cast iron MC mount is a little thicker (currently I have the spacer in place).


Sal

Sal I've never used that for the clutch system. Use the FSM method along with what Kb has added. Small pedal movement till you know you have fluid in everything. Then you can go to longer pedal movements to finish the air off.

On the M/C. I'm not an authority on this, but I'd toss it and try another part...easy for me to spend otherpeople's $. JMHO, try using a tissue to soak up what you can see. Re-bleed the system. Check it again & see what's up, then make a call. If I saw fluisd the next time around? In the trash with that one.

Yes, leave the spacer. It maintains the right geomerty so the M/C's piston stays in a flat plane when it travels the bore as it is pushed by the push rod.

:cheers:
Tom

[salvatore1]

Heres how I did it and worked 100%.
Open up the master so you can see the fluid,Roll the drivers window down use a baseball bat or something to press the clutch peddle very sightly about 1 or 2 inches, keep it there Small bubbles with surface in the master, release and do this several times. Until no more bubble come up. You should be 90%. peddle the clutch down with the foot several Times slowly. You should have a rock hard peddle. If you need to reverse bleed this there is trouble.
These systems are quite good, and should self bleed most air out in normal use. Good luck

I tried the "self bleeding" method. I had my son push the pedal in 2 or three inches and hold it. I did see a very very very small spray of bubbles (like pin tips) for the first try. After that absolutely no more bubbles no matter how many times he pumps it.

Unfortunately I still am not getting 100% disingagement from the clutch (especially in 1st and reverse). Mind you its not bad, but I can still feel the car barely want to move when I put it in first with the pedal all the way to the floor. If I pump the pedal a couple of times I almost never have a problem getting it into 1st or reverse.

All I can think is that threre is some major air pocket in there somewhere which cannot surface - should I be reverse bleeding this thing now?

[rhipsher]

Yes reverse bleed it salvator. Just have your son stand over the brake fluid reservour and tell you when there are no more air bubbles coming up and then just fill it up the rest of the way. You should notice instant preasure in the clutch peddle. And your done. All we did was fill a big serenge with clutch fluid. Loosen the bleed screw and connect a clear rubber hose from the serenge to the bleed screw and slowley sqweeze the serenge. Your reservour will start to fill up with fluid and air bubbles. Once there are no more air bubbles just top off the reservour and thats it. Usually takes 5 minutes.

[salvatore1]

Yes reverse bleed it salvator. Just have your son stand over the brake fluid reservour and tell you when there are no more air bubbles coming up and then just fill it up the rest of the way. You should notice instant preasure in the clutch peddle. And your done. All we did was fill a big serenge with clutch fluid. Loosen the bleed screw and connect a clear rubber hose from the serenge to the bleed screw and slowley sqweeze the serenge. Your reservour will start to fill up with fluid and air bubbles. Once there are no more air bubbles just top off the reservour and thats it. Usually takes 5 minutes.

Funny you mention the serenge method because I happen to have a 10 ounce one I was previously using to draw old fluid from the reservoir (to flush my clutch fluid). This particular serenge was designed to inject liquid seasoning into turkeys - will this work (why does this sound funny?)...lol

[LGAFF]

Are you sure the rod is on the clutch fork?


I think the bleeding issue is alittle overplayed, mine worked from the 2nd or third pump....I had issues at first but the rod was not in the fork....once I put the rod in the fork provision, no issues

[salvatore1]

Are you sure the rod is on the clutch fork?


I think the bleeding issue is alittle overplayed, mine worked from the 2nd or third pump....I had issues at first but the rod was not in the fork....once I put the rod in the fork provision, no issues

The rod is definitely at the fork I made that my main priority when installing the slave (I heard horror stories about what happened when people installed it off the center of the fork). Like I said, the clutch is working (pedal pressure is there, and I can shift), its just not 100%

[tomtom72]

JMHO, assuming that the install went correctly, and that you give the bleeding a shot with the turkey baster, and you still are not at 100% dis-engagement then you have deffective parts.

Sal, that is the only conclusion left.

This is like I'm watching a replay of what I went thru back in 05. However, I would e-mail Bill as he may see something that we're all missing on this case. Remember, according to GM a 20% deffective rate is at the top of their acceptable range. They said back in early 2000's that the spillage rate was 15% and that's why they were not doing much about it till Bill and Superrior brought it to their attention. It looks like they never really did much about the quality control issue to me anyway. JMHO:redface:

[salvatore1]

Are you sure the rod is on the clutch fork?


I think the bleeding issue is alittle overplayed, mine worked from the 2nd or third pump....I had issues at first but the rod was not in the fork....once I put the rod in the fork provision, no issues

Tell me - what are symptoms of not having the rod seated correctly on the fork? I mean, its obvious you will not get any clutch action (engage/disengage), but would it still possibly work, just not perfectly?

[salvatore1]

Yes reverse bleed it salvator. Just have your son stand over the brake fluid reservour and tell you when there are no more air bubbles coming up and then just fill it up the rest of the way. You should notice instant preasure in the clutch peddle. And your done. All we did was fill a big serenge with clutch fluid. Loosen the bleed screw and connect a clear rubber hose from the serenge to the bleed screw and slowley sqweeze the serenge. Your reservour will start to fill up with fluid and air bubbles. Once there are no more air bubbles just top off the reservour and thats it. Usually takes 5 minutes.

As unbelievable as this may seem to be, I think it's fixed. I reverse bled it and you were right - a whole bunch of bubbles came to the top (aka rosanne barr in a bathtub). Who would have thought a $2 kitchen untensil would work like that.

I felt comfortable enough to drive it to work (40 miles each way), and after I drove it awhile the pedal seemed even firmer. I can shift it now with my pinkie - and I think this is what we are after here.

I do still think, however, there might still be air in the system because I absolutely must have the pedal all the way to the floor board, otherwise the car will complain.

Thanks guys