My thermostat housing insists on leaking!!!! I've replaced the gasket 3 times now and each time i've put different types of sealants on it. This last time i put gasket sealant #2, what the guy down at my local autoparts store recommended for this kind of stuff. Yet it STILL leaks!! I've checked the housing and the spot were it bolts up to for imperfections and there are none.. what is up!??????

 

Have you tried just a dry gasket?Are you torquing it to the right values?

 

Are you sure its coming from the gasket seam. i have seen them have a hair line crack and leak from that. Or the t-stat is slipping out of its step down area a little and not letting it seal all the way.

 

Also have you checked to be sure the hose is good and clamped down good? could be a leak there, best thing i can think of is let the SOB get hot and look to see where it is coming from. if its the thermostat housing, go to your local pick-n-pull and swipe one. be sure to take off any old gaskets and you should be fine. food for thought. Oh also make sure its not one of the chrome housings, i've heard that the chrome housing units are notorious for leaking on any make or model, not just cherokees. but thats just my experience with them. good luck!

 

If warpage is suspected you can try using some 800 grit wet/dry sand paper.Lay the paper on a good flat surface and run the mating surface of the housing across it a few times.Doing this will quickly reveal any warpage and I dont see why you couldnt just keep going until the surface is flat again.

 

Lay a smooth layer of silicone on the housing, use your finger to make sure its even.
Now do one side of the gasket the same way.
Lay it on the housing and let it get a skin on it.
Almost firm even.
Then reinstall the housing, just snug the bolts finger tight and let the silicone finish setting up.
Now tight it down evenly, I hate the housing on the 4.0 its fragile, I've broke a few of them.
It should not leak now.

 

Yes I have tried it dry, but it eventually started leaking. I tightened it until I couldn't anymore since inside my haynes manual it tells you how to remove everything, but it doesn't state any torque values or how to replace the part.

This could be a possibility but I inspected the housing and it didn't seem to have any imperfections, neither did where it bolted too. And i'm almost positive that the t-stat didn't move. But it could be a possibility cause it is sort of hard to move it around to get in there.

Thanks for all the help though. I tightened it up a little more and I'm going to see if its continuing to leak tomorrow.

 

That might be your problem, if you put all you had into tightening it. Could of easily cracked the housing.

 

I do it as tight as I can with one hand...

 

How much sealant did you put? Whenever i did mine i just put a real thin layer on the gasket and allowed the appropriate time to dry but it leaked. So i took it back apart and this time pretty much coated the gasket front and back (not like dripping or anything), no more leaking.

 

I thought you were supposed to get it sung to super *** tight..becasue itd push out off the RTV???

 

Too tight is too tight. You can strip threads, snap bolts, crack housings and other not so awesome things. Haynes manuals can be useless sometimes, this time is no exception. Not having torque specs sucks. Does anyone know the torque???

 

I hang tightened mine using rtv sealant form harbor..no problems, just get it tight, no need to go ape **** tight..

 

i believe the torque for the themo housing is 13 ft. lbs. If you look at the front of the chapters they usually have torq. values and if not it is allways in chpt.1 and if not there, a standard torq. section in the first couple pages.

 

I'm now thinking the casting of the housing has warped over time, since when i first replaced it I used no sealant, just a gasket and it ran fine for a month and a half without drips. Then slowly I'd see green puddles under it after school. Took it off, added a new gasket, smothered it in rtv stuff, rebolted it on, after two days it started leaking again. Redid this time with a different gasket that was a peel and stick type, covered it in sealant #2, but not a ton this time and it started leaking a day after.
I'm thinking of cleaning up the stock housing since it did not leak at all, I just replaced it since the po left it sitting for 8 years. And what i have learned from this jeep is usually the original is better than an aftermarket copy.