Water pump installation Q

[fiatslug87]

Replacing water pump on an ‘88 4.0L. FSM says “the gasket is installed dry”. I’ve always used RTV with the gasket, haven’t checked the FSM before. What do you all do?

[eaglescout526]

I’ve installed mine dry. There’s a gasket I have from Chrysler that has some RTV stuff on it. 

[89 MJ]

I’d do a skim coat of rtv. No way am I trusting a gasket alone to take up 30 years worth of possible corrosion or warping on the block, nor am I trusting today’s manufacturing processes to give me a decent finish. 

[AZJeff]

3 hours ago, 89 MJ said:

I’d do a skim coat of rtv. No way am I trusting a gasket alone to take up 30 years worth of possible corrosion or warping on the block, nor am I trusting today’s manufacturing processes to give me a decent finish. 

Agreed.  I ALWAYS use RTV on water pump, thermostat, and timing chain cover gaskets.  The thin film helps seal any irregularities in the surfaces, and makes gasket removal MUCH easier if the job needs to done again for any reason.

[GonzoTheGreat]

I always do a thin layer of RTV as well. Not so much that it squishes out inside and pieces break off, but just enough so that the gasket is not dry.

 

It might work just fine dry, to be fair, I’ve never tried. I would make sure it’s a good brand name gasket though, and pay close attention to torque specs.
 

Hell, now I’m curious. Maybe I’ll try it dry next time I do one, just to see. 

[75sv1]

I use Hylomar on the gaskets. I like the blue better than the red.  I feel they peel off better, if I need to replace stuff down the road. Not on head gaskets though, nor the intake gasket. 

[87MJTIM]

I used Felpro gaskets all around on a 93 4.0 in my CJ.  Felpro states in the instructions that RTV is not needed.  I did not use any RTV (unless instructed) and so far no leaks.

 

Your results may vary.

[Gjeep]

skim coat of rtv both sides with Mopar gasket.

[AZJeff]

1 hour ago, 87MJTIM said:

I used Felpro gaskets all around on a 93 4.0 in my CJ.  Felpro states in the instructions that RTV is not needed.  I did not use any RTV (unless instructed) and so far no leaks.

 

Your results may vary.

“Not needed” does not mean “not beneficial”.  Even if all it does is make the next gasket removal job easier, it’s worth the small effort to add a film of RTV before installation.
 

[87MJTIM]

18 minutes ago, AZJeff said:

“Not needed” does not mean “not beneficial”.  Even if all it does is make the next gasket removal job easier, it’s worth the small effort to add a film of RTV before installation.
 

Good eye.

 

I chose my words carefully.

[Eagle_SX4]

If ease of removal is you top concern and you are using a paper/fiber gasket use some grease. Just coat the gasket in a light coat of grease an this will do 2 things 1 help the gasket to swell to create a better seal and 2 it won't stick to anything making it really easy to remove. I have had good luck using this method.

 

If you do use silicone make sure it is rated for the type of fluid the gasket will be sealing. The glycol content in most coolants can eat through some silicones. I have also had good luck with this method.