Leaky Waterpump - need opinion
Thread Starter
Cruising
Joined: Apr 2010
Posts: 10
Likes: 0
From: WI
Leaky Waterpump - need opinion
A couple of weeks ago, I took my C5 out of storage. I noticed a small puddle of coolant under the car, toward the rear of the engine. The car needed to sit at least 6 hours or overnight to see any leakage. Since I didn't see it coming from the obvious places, I took it to a dealer for diagnosis. They said the water pump needed replacement. I decided to replace the water pump myself and after RnR 2 times on the vehicle I was upset to see it leaking (after only 15 minutes of sitting) So, I put the original water pump (62K miles on it) with new gaskets back on. And was surprised to see no leaks at all. I looked closer at the replacement part and found a burr on the mounting flange, which I believe was the cause of the leakage with my new part. I contacted the seller of the part and they offered to replace or refund. MY QUESTIONS ARE: What would cause my original pump to leak where it took overnight to see. AND since I replaced the original water pump with new gaskets, how likely is it that this was the only problem. I realize that you can't say for certain either way - I am looking for input - should I get my money back or should I exchange and replace the water pump?
Le Mans Master
Joined: Dec 2005
Posts: 8,581
Likes: 965
From: Communist Colorado
Sometimes, especially when a vehicle sits, as you said yours was in storage, coolant leaks will develop at the weakest points. Like for instance a hose clamp, or a loose water pump bolt etc. If a water pump is really bad, then 99%of the time coolant will leak from the "weep" hole.
Some coolant leaks are only evident when cold, some only when hot. If your pump was loose, then maybe thats why its not leaking now... perhaps the retightening of the bolts fixed the problem.
I would go ahead and install a new pump since its an easy job and the mileage on the old one. Start fresh with a new pump and use a 50/50 mix of Dexcool and distilled water.
Some coolant leaks are only evident when cold, some only when hot. If your pump was loose, then maybe thats why its not leaking now... perhaps the retightening of the bolts fixed the problem.
I would go ahead and install a new pump since its an easy job and the mileage on the old one. Start fresh with a new pump and use a 50/50 mix of Dexcool and distilled water.
Pro
Joined: May 2007
Posts: 609
Likes: 8
From: Round Rock TX
I had to replace my water pump this weekend as well. The replacement I got was an AC delco water pump and upon inspection I noticed a bur on outside edge of one of the water inlets. I took a file and cleaned it up. Very curious quality controls.
