I have a 1995 F-250 7.3, it started leaking coolent from what looked like the thermostat housing. So I replaced the o-ring and the neck that the top radiator hose connects to, yet it still leakes but not from that part. It seems to act like a gasket or o-ring problem because as soon as I drive it it warms up and stops leaking but as soon I shut off the engine its starts leaking again. Any help on locating this would be greatly appreciated.

F-250 7.3 Powerstroke

Mods: S and B Cold Air intake, Wicked wheel, 3 inch straight pipe

 

Most buy the riffraff billet housing, me I just used a crap load of silicone with the O ring in place

 

Another option is the thermostat housing flange ring - https://www.strictlydiesel.com/p-267...sing-ring.aspx . Comes with a new o-ring and MUCH higher quality bolts. Requires no messy Pizza Hut cheese (aka RTV).

 

There's also a fix that has new bolts, a true O-Ring, and a piece that fits over the top to keep housing from bending while tightening.

 

^^^^^^ Um, see link in post #3.....

 

always replace the t-stat housing bolts with socket headed cap screws.

The other ones break to easy.

 

Doh!! Guess I should read closer...great minds!

 

Not to mention you can round the heads of the factory bolts just by looking at them.

 

Man, so true. I hated the nightmare I went through with this poorly designed engineering on such a simple part.

 

I wonder if they gave the engineering job to a new grad/trainee. Such a simple part they figured no way to screw it up. Interesting how complicated stuff gets a lot of attention and sometimes the simple parts cause more trouble because no one really focuses on them.

Or, more likely, the accountants said that the original properly designed part was too expensive.

 

Whatever the reason, I thank the starts, the man upstairs and the patron saint of tools for Irwin Bolt-Grip extractor sockets. Saved my bacon on this job.

 

Found out what it was. It was a bearing in the waterpump wear the fan mounts, it leaks when the pressure leaves. So I replaced the water(since it never has been) and no more leak

 

the aluminum waterpumps have a strong tendancy to leak on these trucks.
The bearing seal rusts and lets water into the bearings.