Relatively new to DIY auto repair and learning as I go. I've had my truck for about 4 years and am slowly going through everything. I am replacing the thermostat in the cooling system but am having an issue with leakage from the housing. I am using the upper and lower OEM gaskets that I bought from cool cruisers of Texas. Not sure what I am doing wrong. Happy to give more info if needed but looking for some guidance. Thanks
Thermostat housing leakage
- Thread starter Behfra
- Start date
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We have no idea what you're doing wrong either (if anything) without someway of seeing it.
We have no idea what you're doing wrong either (if anything) without someway of seeing it.
Not sure where the leak is coming from, but on my housing I had a leak coming from where the top half mates to the bottom. I used a large thick metal plate with sand paper to LIGHTLY sand the housing until true.
- Thread starter
- #4
Thabks for the feedback. The old gasket was stuck pretty good on the lower part of the housing so I used a razor blade and sandpaper to get it off as best I could. Then I put thermostat -> lower gasket -> upper gasket -> upper housing. The area is circled is where it is leaking from when I fill with coolant.
The horizontal surface of the bottom housing looks fine.
You don't show the upper, so... Could either be that or the housing is warped, cracked or gasket has failed where the bottom of the housing bolts to the cylinder head. Be careful snugging up those two bolts, you break one and you're F'd.
If it's not leaking from the rear gasket, you could use a little Blue Permatex on the four-hole gasket -that will help seal any warpage in the housing.
You don't show the upper, so... Could either be that or the housing is warped, cracked or gasket has failed where the bottom of the housing bolts to the cylinder head. Be careful snugging up those two bolts, you break one and you're F'd.
If it's not leaking from the rear gasket, you could use a little Blue Permatex on the four-hole gasket -that will help seal any warpage in the housing.
There's some good details below:
Yep, lower housing surface looks good. If the upper surface of the housing is trashed, I've used JB weld to skim coat any pitting then sand with 400 grit on a flat plane (like a piece of granite countertop or thick glass). I also add a VERY thin smear coolant-safe sealant to upper and lower housings before sandwiching the gasket and tightening down. You don't want the sealant oozing into the internal coolant area or into the bolt holes. Mine usually still leaks slowly for about a month when I do that job, but then it kind of "self-seals". I use the Toyota red full strength coolant diluted with distilled water to taste fwiw.