LT5 Water Pump - ZR-1 Net Registry Forums

Jagdpanzer · 03-18-2018

Anyone ever fully disassembled a LT5 water Pump?
I'm looking at tearing down a used one I have. So far I have pressed off the belt pulley flange. Not apparent to me which direction the shaft should be pressed out from, impeller side or drive pulley side? Afraid of destroying the pump body if I should get it wrong.

-=Jeff=- · 03-19-2018

I believe Marc Haibeck has, at least he did offer a rebuild service on them

Marc Haibeck · 03-21-2018

Hi Phil,

Push the bearing assembly out through the back of the housing. The housing needs really good support so that you don't crack it. Heat the housing to 175 degrees F to reduce the grip on the bearing.

Don't break the impeller. I cut the shaft off close to the impeller and then press out the stub with plenty of support. The bearing is 5/8" on the front and 12 mm on the rear. It looks like the British engineers got their way.

XfireZ51 · 03-21-2018

Quote:

Originally Posted by Marc Haibeck

Hi Phil,

Push the bearing assembly out through the back of the housing. The housing needs really good support so that you don't crack it. Heat the housing to 175 degrees F to reduce the grip on the bearing.

Don't break the impeller. I cut the shaft off close to the impeller and then press out the stub with plenty of support. The bearing is 5/8" on the front and 12 mm on the rear. It looks like the British engineers got their way.

😂☺️😁

Jagdpanzer · 03-21-2018

Thank you Marc, I’ll give it a try

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phrogs · 03-21-2018

I have a couple that would be good guinea pigs.

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Dynomite · 03-21-2018

I had a new water pump spin an impeller. That was a bit difficult to diagnose (Did not see any cracks in impeller)

I gave that water pump to Marc for his Data Base as that had to be a first

Phil......take some photos if you can of the process of removing Water Pump Bearing

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Jagdpanzer · 03-21-2018

Marc,
If I chuck up the pulley end of the shaft in my lathe and carefully bore out the shaft from the impeller is possible to press the bearing and shaft out from the impeller side toward the pulley side? Looks to me that side of the housing can be better supported for handling the press forces.

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Marc Haibeck · 03-22-2018

Hollowing out the shaft is a good idea. You are more of a machinist than me so you will need to judge the process.

It's very important to save the impeller as well as the housing. A pump expert, Dean Nelson ZR-1 owner, told me that the impeller is the heart of a pump's efficiency.

Jagdpanzer · 03-22-2018

Thank you Marc.
I tried it this evening and it worked fine. Was surprised at how hard the shaft material was. It just laugh at HSS drill bits. Had to get after it with a carbide tipped boring bar.
IMG_1275.JPG

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03-18-2018	#1
Jagdpanzer Join Date: Apr 2007 Location: Northern VA Posts: 2,644	LT5 Water Pump Anyone ever fully disassembled a LT5 water Pump? I'm looking at tearing down a used one I have. So far I have pressed off the belt pulley flange. Not apparent to me which direction the shaft should be pressed out from, impeller side or drive pulley side? Afraid of destroying the pump body if I should get it wrong. __________________ Phil Wasinger 1994 Torch Red ZR-1 WAZOO Member George Braml Intake

03-19-2018	#2
-=Jeff=- Join Date: Jul 2007 Location: Bartlett, IL Posts: 7,132	Re: LT5 Water Pump I believe Marc Haibeck has, at least he did offer a rebuild service on them __________________ 1990 Corvette ZR-1 #1051 Watson Headers (2" Primary) - 3" Magnaflow Bullet cats - LT4 Catback Late Model IH - Plenum Coilovers - 4.10s Custom Interior NCM Lifetime Member #978

03-21-2018	#3
Marc Haibeck Join Date: May 2007 Location: Addison IL Posts: 239	Re: LT5 Water Pump Hi Phil, Push the bearing assembly out through the back of the housing. The housing needs really good support so that you don't crack it. Heat the housing to 175 degrees F to reduce the grip on the bearing. Don't break the impeller. I cut the shaft off close to the impeller and then press out the stub with plenty of support. The bearing is 5/8" on the front and 12 mm on the rear. It looks like the British engineers got their way.

03-21-2018	#5
Jagdpanzer Join Date: Apr 2007 Location: Northern VA Posts: 2,644	Re: LT5 Water Pump Thank you Marc, I’ll give it a try Sent from my iPhone using ZR-1 Net Registry __________________ Phil Wasinger 1994 Torch Red ZR-1 WAZOO Member George Braml Intake

03-21-2018	#6
phrogs Join Date: Jul 2004 Location: Kalamazoo MI Posts: 1,738	Re: LT5 Water Pump I have a couple that would be good guinea pigs. Sent from my SAMSUNG-SM-G890A using Tapatalk __________________ JOHNNY P Currently own 90 ZR-1 #845 DRM 500 engine package 90 #226 Might be a parts car not sure yet

03-21-2018	#7
Dynomite Join Date: Aug 2009 Location: South Dakota/California Posts: 3,788	LT5 Water Pump I had a new water pump spin an impeller. That was a bit difficult to diagnose (Did not see any cracks in impeller) I gave that water pump to Marc for his Data Base as that had to be a first Phil......take some photos if you can of the process of removing Water Pump Bearing Sent from my iPhone using ZR-1 Net Registry __________________ Left Clickable links -Solutions- LT5 Modifications/Rebuild Tricks Low Mileage ZR-1 Restoration 1990 Corvette (L98) Modifications LT5 Eliminated Systems LT5 Added Systems LT5/ZR-1 Fluids 1995 LT5 SPECIFIC TOP END REBUILD TRICKS Last edited by Dynomite; 03-21-2018 at 05:59 PM.

03-21-2018	#8
Jagdpanzer Join Date: Apr 2007 Location: Northern VA Posts: 2,644	Re: LT5 Water Pump Marc, If I chuck up the pulley end of the shaft in my lathe and carefully bore out the shaft from the impeller is possible to press the bearing and shaft out from the impeller side toward the pulley side? Looks to me that side of the housing can be better supported for handling the press forces. Sent from my iPhone using ZR-1 Net Registry __________________ Phil Wasinger 1994 Torch Red ZR-1 WAZOO Member George Braml Intake

03-22-2018	#9
Marc Haibeck Join Date: May 2007 Location: Addison IL Posts: 239	Re: LT5 Water Pump Hollowing out the shaft is a good idea. You are more of a machinist than me so you will need to judge the process. It's very important to save the impeller as well as the housing. A pump expert, Dean Nelson ZR-1 owner, told me that the impeller is the heart of a pump's efficiency.

03-22-2018	#10
Jagdpanzer Join Date: Apr 2007 Location: Northern VA Posts: 2,644	Re: LT5 Water Pump Thank you Marc. I tried it this evening and it worked fine. Was surprised at how hard the shaft material was. It just laugh at HSS drill bits. Had to get after it with a carbide tipped boring bar. IMG_1275.JPG Sent from my iPhone using ZR-1 Net Registry __________________ Phil Wasinger 1994 Torch Red ZR-1 WAZOO Member George Braml Intake