Ok, so I'd say within the last 1-1/2 years I've replaced my gasket 3 times. Well make that 4 cuz it's leaking again. The gasket it self is about blown out again.


My question to you guys is, what can I do to get the damn thing to stop blowing out.


I use a regular soft gasket with RTV sealant. I let the car sit for 24hrs before driving it to let the RTV sealant cure. It's a 355 with moderate horsepower. The whole cooling system is stock. The temp of the car doesn't overheat, stays at it's normal range without a problem. So why can't I keep a gasket on the car to save my life?


Thanks to all who reply

I thouroughly cleaned the block and waterpump with brake cleaner first. Then applied a thin layer of rtv on both sides of the gakets, let it tack up then install and torque bolts down evenly and to spec. I think it was 30lbs? Has'nt leaked in almost 3 years now. Theres no secret to it.

Maybe the surfaces on that wp are'nt true?

try a paper gasket with sealer? Ive done a dozen or so water pumps on different cars and yet to have one leak.

Are you using the bolts that were there when you purchased the engine or car? The reason I'm asking is that the bolts may be too long, they may be bottoming out on something making you whink that they are tight when they are almost tight. You may want to remove the pump and make sure the mating surfaces are absolutely clean and true. I would then take a thread chasing tap down the threads a couple times. While you have the water pump off lay it down on something that is perfectly flat and see if the casting isn't warped where it meets the block. When you put it back together use either mega black or ultra black, in conjuction with a new gasket. Have you been using the blue junk silicone by chance?

ooo slow, not to agrue with ya, but IIRC, gray RTV is made for waterpumps

I use a paper gasket with the blue sealant. But I have a can of the black stuff in front of me. I would use a razor blade to clean both surfaces.


Ok, so I will clean both surfaces good enough to eat off of. Use paper gaskets and the black RTV Silicone. And wait 24hrs before driving the car, I just start it to see if it leaks then shut it off. If this doesn't last I'll weld it on...


Anyone use just the RTV Silicone without a gasket?

As Slow80sc said, make sure the bolt holes and bolts are clean. They like to rust up and can have hardened sealer on the threads. Makes it hard to judge how tight your getting them.

I don't like using rtv on water pump and t-stat gaskets. I either use weatherstip adhesive glueing them to the pump just to hold them in place. Or my personal favorite is GM thread sealer with teflon.

My take on rtv is it's a gasket replacer, not a gasket sealer.

The Right Suff works well when rtv is needed.

What kind of fan are you running. I had an out a badly out of balance fan on my vette that caused enough flex on the pump bolt to blow gaskets.

I use nothing but #2 Permatex on the water pump gaskets and bolts and HAVE NEVER had a water pump gasket blow or the bolts leak. You can keep your RTV as far as I'm concerned.

When you start messing with motor plates that sandwich between the block and the waterpump, you gain a whole new respect for a GOOD GASKET. With two of the gaskets hidden behind the plate it's pretty nerve racking as you bolt everything up. I go to CSK and pick up- 2 sets of FelPro blue pump gaskets, give the block a light smear of "the right stuff' ,,, a gasket, another light smear of 'the right stuff',,, set the motor plate in place,,, a smear of 'ther right stuff' on th emotor plate,,,, another gasket, a final light smear of 'the right stuff' on the backside of the waterpump and bolt it all up. With good stainless steel bolts snug the pump bolts down to a good 35-40lbs.

Bet you can guess what my preferred gasket sealer is........ :)