Does the thermostat housing have a paper gasket?

[VikingTrad3r]

2006 yukon xl denali. 264000 miles.

the truck wasn't warming up very well so i pulled the tstat. a chunk of the pistons rubber seal had come loose and lodged itself in a way that didn't allow it to close. there was also a paper gasket on the housing.

have the new tstat and it didn't come with a paper gasket for the tstat housing.

i have looked online and it really does not look like it is supposed to have one. yes this tstat has the rubber oring seal on it.

heres the thing. its weeping. aaaannnnddd when i pulled it off, there WAS a paper gasket.

I am thinking perhaps a previous owner ran into the same thing and installed a paper gasket. i really don't want to do this but im going to have to do something.

comments?

 

[zraffz]

No gasket. Thermostat has an o-ring. If it leaks and that o-ring isn't damaged, it isn't properly torqued or its warped.

 

[SnowDrifter]

There's not supposed to be a paper one

 

[Fless]

It depends on the thermostat housing and the water pump. My '04 took both the rubber and paper gaskets. The new AC Delco Pro water pump came with both, and the instructions said to use both. Believe me, we tried it without the paper gasket but it leaked a little (properly torqued), so we added the paper gasket and all is good.

EDIT: now that I think about it the AC Delco thermostat (12T121D) -- not the water pump -- was what came with both gaskets and instructions to use both.

 

[VikingTrad3r]

I checked this morning after the install and it was actually dry. perhaps it was just moist from the install.

i'll check later today again after running it.

the heat issue is definately fixed. that rubber had lodged in there and kept it flowing all the time.

 

[VikingTrad3r]

It depends on the thermostat housing and the water pump. My '04 took both the rubber and paper gaskets. The new AC Delco Pro water pump came with both, and the instructions said to use both. Believe me, we tried it without the paper gasket but it leaked a little (properly torqued), so we added the paper gasket and all is good.

EDIT: now that I think about it the AC Delco thermostat (12T121D) -- not the water pump -- was what came with both gaskets and instructions to use both.

thanks for this. i am a huge fan of this stuff called hylomar. used correctly you can have a metal to metal gasket that will last forever. its a non setting compound. if this starts to leak again, i will pull it apart, save as much coolant as i can, and use the hylomar on it and it will be solved.

VT.

 

[Fless]

A few heat/cool cycles should tell you if it's going to leak.

 

[SnowDrifter]

That hylomar stuff is pretty neat


As to how the paper got into the t-stat, I'm thinking it was from a previous gasket replacement and some sloppy scraping/clean up.

FWIW on my rig, I have only the rubber o-ring used and it sealed up just cherry. That should be pretty typical unless a part is gouged/warped/corroded/etc, which is the only time I entertain paper gaskets. Beyond that, they're such a pain in the ass to clean up I try to stick with rubber stuff only.

 

[VikingTrad3r]

That hylomar stuff is pretty neat


As to how the paper got into the t-stat, I'm thinking it was from a previous gasket replacement and some sloppy scraping/clean up.

FWIW on my rig, I have only the rubber o-ring used and it sealed up just cherry. That should be pretty typical unless a part is gouged/warped/corroded/etc, which is the only time I entertain paper gaskets. Beyond that, they're such a pain in the ass to clean up I try to stick with rubber stuff only.

I re-did it with hylomar. all good. it is by far the best sealant out there. aerograde and for a reason.

anyway, it wasn't paper in the valve. it was rubber from the tstat itself that had somewhow come loose and lodged itself.

i agree 100% about paper gaskets. few years back i refurbed an L98 tpi corvette engine right down to the head gaskets. scraping all the oem gaskets was by FAR the worst possible job of the hole enchilada...and that says alot because i decked my own heads in my garage and used the drill and rubber line method to grind my valves. i searched high and low for the best possible gasket maker and it was hylomar. it never sets. and i can now pull my engine apart and put it back together without destroying any of the gaskets. its amazing stuff. expensive unless bought on amazon.