Thermostat Replacement

Topic: Thermostat Replacement (Read 2857 times) previous topic - next topic

Thermostat Replacement

June 23, 2014, 09:08:43 PM

So I decided to go with the 180* T-Stat. It was a pain since hoses and clamps were original and that right bolt is so annoying but after a couple of hours I had the thermostat in with a new upper radiator and bypass hose. Drove at least 5-10 miles yesterday , all good. Drive it for 10 minutes tonight and there's a leak in the thermostat area.

I didn't put a clamp on the T-Stat side of the bypass hose so I hope that's it. But it's probably the T-Stat with my luck, how can it be fine one day and then leak the next? I sed both the housing and manifold side clean and had an adhesive backed gasket holding it in place. Are there any tricks I'm missing here? I wouldn't mind if I didn't have to drain the coolant again. Any ideas on what I'm missing would be great. Lol

Thermostat Replacement

Reply #1 – June 23, 2014, 09:31:48 PM

With no hose clamp I bet it's leaking.

If not it could be the housing gasket. I've had good luck coating both sides of the gasket with ultra black and then assembling. Over time the aluminum gets pits and the ultra black fills the voids.

Thermostat Replacement

Reply #2 – June 23, 2014, 09:39:35 PM

I'm going to put a clamp on that side and hope that is it. If not, I give up my belief in no RTV on T-Stats and I'm going to make sure this thing doesn't leak if I have to do it again. I'll give the Ultra Black a try if I unfortunately have to.

Thermostat Replacement

Reply #3 – June 24, 2014, 06:54:15 AM

Stat gaskets are garbage these days. They slot the bolt holes and they can leak if not glued to the housing or manifold. That is why i make my own from VELEMOID. Also you need to use super weather strip adhesive to glue the stat in the recess in the manifold . Sometimes the stat moves and gets caught between the neck and manifold causing a leak. If you are dealing with a 302 you need to look up my post on how to deal with those bolts to make a stat change a 10 Minute job. Personally i never use RTV on a stat housing. It will leak and you will be back to square one in no time. Take you time and get the proper gasket. Ford makes them without the slots or make them like i do. Have a good Tuesday guys.

Note all hoses must have some type of clamps. Otherwise when the pressure builds it will definitely leak as some point in time. Personally i have never seen a hose in a cooling system that does not have some sort of clamping arrangement.

Thermostat Replacement

Reply #4 – June 24, 2014, 09:17:17 AM

I searched on here before I did it and didn't find much info, I guess I should have searched harder. Lol

Well I put a clamp on the T-Stat side of the bypass, cleaned up the coolant under the housing and stuffed a paper towel underneath. Warmed it up to full temp to get coolant flowing through the housing, drove it aggressively for 10-15 minutes and no leak. Sat for almost an hour, still no leak. I drove it to work(less than 7 miles) and temp never got over half with the A/C blasting. When it did leak yesterday, it went right over half within a few minutes of driving.

It's going to sit for almost 9 hours. I hope it's not leaking when I get out. If it's not, I will tell everyone I know how awesome the Stant adhesive backed gaskets are. Lol

Thermostat Replacement

Reply #5 – June 25, 2014, 09:19:51 AM

Well, the car sat overnight and I took it to work with no signs of a leak. So I guess it was the lack of a clamp on the bypass hose. I guess I learned my lesson and I don't have to do the T-Stat again(for now).

Thermostat Replacement

Reply #6 – June 25, 2014, 11:44:35 AM

Do they make a rubber/silicone thermostat gasket for that application? For my 3.8, you can get this. Which turns a t-stat swap from a c to a breeze. No more sing the old paper gasket/RTV out!

Thermostat Replacement

Reply #7 – June 25, 2014, 11:58:41 AM

Quote from: JeremyB;435165

Do they make a rubber/silicone thermostat gasket for that application? For my 3.8, you can get this. Which turns a t-stat swap from a c to a breeze. No more sing the old paper gasket/RTV out!

That's pretty cool, but I haven't seen anything like that for the 5.0.

Thermostat Replacement

Reply #8 – June 25, 2014, 01:56:34 PM

I want to try getting an oring thermostat, but i don't know anyone who's used one.

thermostats really aren't all that bad once you've done one a couple times. i can do one start to finish in less then 20 minutes. 10 of those is looking for the ed bolt somewhere under the waterpump when i always drop it.

Thermostat Replacement

Reply #9 – June 26, 2014, 07:03:17 AM

STUDS will set you free on this one. No dropped bolts i guarantee that??? Have a good week guys.