Replacing Thermostat gasket

redxr7

Registered User
Ok, I have changed my Thermostat gasket twice now and it still leaks. This has become a pain now. The last time I changed the gasket cleaned the area completely and let the area dry. I then put some gasket seal on the Thermostat. I also put some on the new gasket and the put it on. I let the gasket and Thermostat seal set for 24 hours. The next day I put gasket seal on the other side of the gasket and then attached the gasket. I tightened the bolts pretty tight. I’m wondering how much I need to tighten the bolts. I’m wondering if I am tightening the bolts to much. Any help with this would be great. This will be my third gasket and I want to make sure it works this time.
 
Take a level and place it across the housing and seeif it is straight or not. It is easy to warp the housing and then it will leak no matter how clean you got it or the engine side.
 
I believe the torque specs for the Thermostat outlet are 15-22 ft lbs, it doesnt need to be too tight.
I use High temp RTV on both sides of the gasket, and assembled it quickly, the RTV doesnt take long to setup. You should do it all at once, not on seperate days.

- Dan
 
I found that it helps alot if your thermostat housing is flat, and the copper rtv is a little past tacky when u bolt her on.
 
Check your rad cap. this happened to me a year ago. (kept blowing themo. gaskets) turns out the 16lb rad cap was opening at 19-20lbs had to buy two new rad caps (16lbs) before I found one that accually opened at 16lbs, haven't had a problem since:)
 
What I've done is take the thermostat housing and rub it across some fine emory paper on a flat board. thus leveling the mating surface on the housing before re-installing it. Then use copper RTV and don't torque it down too much. Let it sit long enough for the RTV to cure and then give it a shot. usually works.
 
I also have a couple of suggestions, having had leaks myself in the past:
1). Don't buy the regular Felpro gasket that has an open slot for the vent pipe hole. Try a Ford dealer (ouch !!) or buy the regular Bird one and cut your own hole in the upper right corner.
2). Take the T/stat housing off, clean it really well and put each ear of the housing (where the bolt holes are) into a vice (with padded jaws) and bent the ears back about 1/16". This will help pull the body of the housing up tight when you bolt it.
3). I've successfully used black RTV on just one side of the gasket only.
4). Take the 2 housing bolts to a part store (probably M8x1.25) and get some matching lengths of threaded stud, nuts and lock washers. Put the studs in the engine block with a little loctite. This way you can put your gasket in place, lock your t/stat into the housing (if you are using the stock 197 deg one, that is) and slide the housing onto the studs. And everything stays in place while you tighten it up.
 
redxr7 said:
Ok, I have changed my Thermostat gasket twice now and it still leaks. This has become a pain now. The last time I changed the gasket cleaned the area completely and let the area dry. I then put some gasket seal on the Thermostat. I also put some on the new gasket and the put it on. I let the gasket and Thermostat seal set for 24 hours. The next day I put gasket seal on the other side of the gasket and then attached the gasket. I tightened the bolts pretty tight. I’m wondering how much I need to tighten the bolts. I’m wondering if I am tightening the bolts to much. Any help with this would be great. This will be my third gasket and I want to make sure it works this time.


Bill what are you doing!? You know I'm just down the road! Give me a buzz and I'll come stop by, I've got two or more of these thermostats housing lying around, we'll find the best one and bolt it on. I've been over this nightmare before, no worries. :)

-B
 
Slab-o-gasket

I fixed mine by just cutting out my own - there was no delicate parts, so I just stuck it on to a clean/scraped thermostat and then cut it out with an exacto knife.
 
Has anyone else had the problem of stripped bolt holes in the intake manifold? I decided to try some studs next time :) The studs found in the inlet plenum happen to be the same thread, and a decent length, might jsut need a washer or two. As far as the thermostat housing - I beat the crap out of it with a hammer until it's straight...then either use a gasket and rtv(both sides), or just rtv.
 
This is what I found on a SC I bought a few years ago. If you notice the thermastat is not in place and the gasket is from a LX.
 

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Now, see, I inadvertently installed a gasket from the NA v6 on my SC ... it leaked like a faucet!!! I got a mile or so down the road and the cloud of steam clued me in to the fact that I had done something wrong. I went to Advance and got the proper SC one (from Felpro) and it worked great. Dealer one is fine too.
 
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