Been having this problem for quite a while. Installed a new waterpump about 1.5 years ago, put thread sealant on the bolts and bolted her right back up. After a few days it started leaking from the the waterpump bolts (mainly on the right side of the engine (drivers side) By leaking I mean I can see seepage afterwords in the valley where the top bolt is and where it trickles down the pump. So I got my torque wrench out and torqued them to spec, which I belive is 30ftlbs. That stopped it almost but it still leaked everyonce in a while, mainly when there was a lot of pressure such as stop/go traffic and the car heats up good.

So I decided to take all the bolts out when I had the coolant drained this past week. Took them all out, cleaned them up w/ a wire brush and put new permatex hi temp thread sealant on all of them pretty good. I went more liberal this time then last, and I also put some rtv hi temp sealant around the heads of the bolts. Figured this sucker won't leak now...

Turn it on, go for a ride and the next day I look, its leaking again, worse then before I took the bolts out again.....WTF am I doing wrong. Did the rtv mess it up, should I torque them more?

 

I never even use a gasket on the pump.........JUST RTV. When I install the bolts they touch the RTV and seal themselves. I have never put anything on the bolts at all.

 

Sorry to hear about the trouble,
You're saying that the coolant is seeping out around the bolts?
That's very odd.

I've always installed my bolts dry as well.
I do use gaskets though, no RTV.
(I've done the RTV-as-gasket deal on other cars and it worked that way too)
The trick is to make sure the mating surfaces are perfecly clean.
Gasket scraper, cleaner and a terrycloth are usually the toold you need.
Check both surfaces for scratches or pits that may be allowing coolant to leak.

 

You MUST use thread sealant on the bolt threads. Use some Permatex 2 and problem will be solved. IMHP you should use the paper gaskets as GM intended.

 

I dont know if you guys understand my problem. The actualy gasket which holds the pump to the block is fine, doesnt leak. For that gasket I used a felpro gasket + rtv. It only leaks around the bolts and I am about out of answers. Whats the difference between permatex 2 and permatex hi temp thread sealant?

 

Dunno, I use number two and have NEVER had a leak.

 

Thread chaser for the bolt holes (maybe some brake cleaner, too), clean the bolts and properly apply thread sealant to them. RTV should never be used as a thread sealant for anything in the cooling system. RTV chunks can end up causing clogs. I have never had any trouble with the water pump bolt, even installing them with no thread sealant.

 

No RTV was not put on the thread....Let me get this straight.

I put permatex hi temp THREAD sealant on the threads, and then I put a dab of regular RTV around just the neck/head of the bolt since that is where it leaks from.

 

Is that stuff make for thread sealant or is it just an all purpose RTV? The only thing I can think of is that perhaps the outside of the pump is too course and doesn't allow the bolt head to sit flush? Damnit I really dont want to drain all the coolant again I just fille the entire system yesterday and bleed it.

 

No sealant or anything on the bolt head. The threads do the sealing. If it gets past the threads, nothing on the bolt head is going to help. Thread sealant is not RTV.

 

I've never used anything on the water pump bolt's threads and have never
had an issue (pump housing has been off/on 3 times).

 

I mentioned in post #7 that I have done them with no sealant, too.

 

I was acknowledging the fact, Rob ... a "me too" (not a dispute)

 

 

Something is wrong, not just the use of sealant. I would chase all of the threads and clean them very well like shoebox suggested. There may be a hairline crack or something that is letting the coolant get by.