Water Pump Gasket: Sealant or no?

[2k1Impala]

For the past 25 or so years I have been using a thin layer of Permatex Part #2(A or B) "Form A Gasket" sealant on both sides of water pump gaskets and haven't had problems with leaking gaskets. But when I disassemble factory installations, it appears they never use any kind of sealant on the gaskets.

Have I been wasting money all these years? Do you guys install dry or with sealants? Should I keep doing what I've been doing or should I give dry a try?

[3400-95-Modified]

I always use a thin layer of sealant around coolant ports, its not a waste of money, yeah it may work with the extra sealant or the same dry but its that piece of mind that you will have a better seal from your part to the gasket.

[IanSzgatti]

no no no... it is a waste of money and my god man you should be ashamed of yourself!! how dare you use common sence!! instead of designing your work to fail you go ahead and ensure a reliable seal... im sickened, i just feel ill.

[2k1Impala]

instead of designing your work to fail you go ahead and ensure a reliable seal... im sickened, i just feel ill.

I knew I had been doing something wrong all these years!

[Z26-T]

*shrugs* at the dealership we leave it dry. If it leaks, replace the gasket... I just like removing paper-like material instead of rubber. If you're using a gasket-maker sealer, why use a gasket, unless you do it 3400-modifieds method. Use sealer where the gasket isn't there. When it comes to spreading sealer on both sides of a gasket, look at the part of your finger that you spread it on. Is it flat? No. So are you going to spread a nice level amount of sealant? Bead it if anything...

Sorry, I just have seen more come backs from people putting sealers on gaskets, instead of just leaving the gasket dry and put it on how it was designed.

[SuzukiGhostRider]

I agree with Z26-T. I never use silicone on gaskets. And I've very rarely had one leak, and those were defective or worn. And if you do it around your coolant areas (ie, water pump, thermostat housing,etc.) you're asking for it. If some of that silicone pops loose, where do you suppose the odds are good of it going? That's right, into the coolant system. 5 years in a GM dealership as a wrench and we never used it to install seals either. So yea, I think you've been wasting your money. The guy who assembled the recently rebuilt engine in the car I bought a few months back had a love affair with silicone. EVERY gasket that I've had opportunity to see thus far (I've replaced the water pump and t-stat and been able to see the silicone on some others) has had silicone smeared ALL over boths sides of the gasket! What's the point in having the gasket then? And like Z said, you're finger is not even.... But it's a debatable issue I guess.

[Z26-T]

When I worked at a general repair shop that's all that we did, smear both sides of the gasket and put it together as fast as we could before it dried, but I saw soo many come backs from not putting the gaskets on fast enough so the silcoln sealed to half of it, but not the other half. Go to the dealership and never see people put anything on gaskets... which makes sense to me. The gasket is made to seal it, if the gasket can't seal it, why bother with the gasket? Gasket technology has been greatly enhanced in the past 25 years. Trust the gasket. Half of the things nowadays that you service regularly have re-usable gaskets ie transmission, differentials (on some vehicles, not all), if you put gasket-maker on these, it ruins them.

[pocket-rocket]

The only thing I put anything on is when I need to hold a gasket to a part. Otherwise I put them on dry.

[IanSzgatti]

well, i'm not gonna lie, when doing things like water pumps I do use some sillycone. thing is though I dont really bead it on... for me it serves two purposes. one is that it will keep the gasket in place, and two is that although there shouldnt be any really poor surfaces, it sometimes ensures that those tiny little imperfections will be sealed.
I dont bead it, I smear it, and although my finger is not flat, it always works out just fine. If I worked in a dealership I wouldnt bother because I'd only have so much time to fuck around... I work in an independant repair shop and time is on my side

[jesterof84]

hmm depends were and what I say paper gaskets i like tacky or permatex had a friend back in the day who loved wellwood contact cement we never had a leak but boy try getting it apart rubber i leave dry
i also spent some time working in a gm dealer and like everyone said we left it dry
it was a surprise to me when i did a head on a 04 duramax and the 3 or 4 pieces of intake were all GM-S (gray RTV) i thought just rtv with 18-30 psi of boost but its what they used

[tractorman]

For me, it depends on the situation. If we're talking about a nice, thick, well-made OEM gasket... then I see no reason for extra sealant. But with a cheap-ass paper-thin gasket like the ones that come with aftermarket water pumps for these engines, I put a little sealant on the gasket.

Same goes for the timing cover gasket on these engines. I replaced mine a while back with a FelPro gasket, and wasn't real impressed with the quality. So I smeared a light coat of sealant around the water ports. Working fine so far.

This is a lesson I learned years ago at a John Deere dealership, rebuilding water pumps. Even with the gasket surfaces perfectly clean, those cheap, thin paper gaskets would often seep coolant. A thin smear of #2 Permatex (or anaerobic sealant like locktite 515, or even RTV, depending on what mood I was in) took care of the problem.

[tractorman]

But you've got to be careful with this sort of thing. I agree with others here in that I've seen the excessive and unnecessary use of RTV cause problems lots of times.

RTV is bad medicine for a thick, squishy gasket like the cork or rubber valve cover gaskets used on lots of old-school engines. In those applications, I use 3M weatherstripping glue to bond the gasket to the valve cover- it does nothing to seal the gasket, but holds it in place and prevents slipping out. Then I make damn sure that the gasket and surface are clean and dry, and install it without any other sealant. The last thing you want in that situation is a sealant that will lubricate the gasket and help it slide out of position.

And in any situation where you've put sealant on a gasket, be very careful to avoid over-torquing. The sealant can help the gasket slide out of place- or even split. In cases where this is a concern, I usually snug up the bolts a bit less than final torque, and give the sealant some time to set up/squeeze out. Then I finish tightening (within reason) the bolts later.