GM Water pump gasket failure !

84rzv500r

Knows just enough to be dangerous!
Joined
Mar 23, 2008
Messages
390
Location
Big Pine Key, FL
Just to let you know I was doing some exploration of the rev limiter in the first 4 gears (still 2 more gears to go) on Friday and ran a good bit at 5500-5800 RPM (4th is about 120-126 MPH). When I had accomplished my mission I shifted into 6th and backed off the throttle. I went about 1/4 mile and the water pump impeller cover gasket let go in an impressive display of steam.

Long story short, disassembly shows two problems with the aluminum water pump GM pn 14058915 on my 502 Ramjet.

1) The gasket was improperly installed from the factory and blew out (I'll post a pic. later) @ 2300 miles since new. I had always had a TINY bit of coolant leakage that I could never find. (It leaked only when running :) The failure was at 5 o'clock facing the front of the motor. I could feel it with my fingers. You can check by feeling, you would feel the gasket sticking out a fair bit when none should be.


2) Comparing the OEM gasket to the Fel-Pro pn 11725 the OEM gasket was three times thicker, soft and swollen. I assembled dry and checked the impeller clearance. I used the Fel-Pro and a thin coat of aviation form-o-gasket to hold the gasket in place. All is better now.

The gasket was $1.60 plus tax

:twitch:
 
CHINA:crap::crap::crap:

Most, if not all AC/Delco stuff is now made in China, including water pumps and clutch kits. DAMMIT Chevy. Wake up. You are shooting yourself in the foot. C-3 outer door handles now are above $130....M:censored: F:censored:
 
If you come on it slow it cuts in at 5850 or so if you bang on it hard you can get 6000 or so before it cuts out...

:cool:
 
CHINA:crap::crap::crap:

Most, if not all AC/Delco stuff is now made in China, including water pumps and clutch kits. DAMMIT Chevy. Wake up. You are shooting yourself in the foot. C-3 outer door handles now are above $130....M:censored: F:censored:

I know. My last water pump, master cylinder, wiper pump, all CHINESE. :crap:
 
If you come on it slow it cuts in at 5850 or so if you bang on it hard you can get 6000 or so before it cuts out...

:cool:

My MEFI 3 redline was programed for 5800. With the Tremec TKO 500 and my 3:08's I kept hitting redline before I knew it especially in first gear. :eek: When that happened it was like hitting a wall, lost all momentum. Seemed like the engine still had some pull left in it. Jim, (aka 427Hotrod)told me that with "our wimpy cam" we were done well before 6 grand anyway. Well, after converting to Accel Gen VII, I was able to easily set the ignition cut out to 6000, and fuel cutoff to 6200. My butt dyno and calibrated hearing says that is a much better setting. Some day I will have to get it to a real dyno and see what is truly going on. Mark, I bet your cutting out ignition at 5800 and engine and/or tach momentum is fooling you at 6000. Sorry didn't mean to hijack the thread.

Bullshark
 
I agree... Now that the motor has some miles it seems to pull much harder above 4500. It just blows the tires away in 1st. When I get some time I'm gonna go with a bit bigger cam, some new valve springs and some ECU adjustments. I'd like to stop the fun in the 6500 range.

I'm also gonna powder coat the intake black :devil:
 
2) Comparing the OEM gasket to the Fel-Pro pn 11725 the OEM gasket was three times thicker, soft and swollen. I assembled dry and checked the impeller clearance. I used the Fel-Pro and a thin coat of aviation form-o-gasket to hold the gasket in place. All is better now.

The gasket was $1.60 plus tax

:twitch:

Glad I read this. I changed the gasket on the water pump I installed today.
 
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