I know everyone who has a 7.3/t-444e motor has had a leak at the thermostat housing. For the longest time IHC was sending a thermostat with a rubber oring gasket. You would have to silicone the snot out of it so it would not leak. Then here in the last year IHC started sending thermostats that had the o-ring molded onto the sides of the thermostat. This was definitely easiser to install but its still sometimes leaks if not siliconed. Here in town they have an IHC research and development facility. At our UPS facility we have around 60 t-444e and 15 -7.3 idi trucks. Our ihc rep is ususally around the shop 3-4 times a year. Usually with experimental parts that he wants checked out. He just came in on Friday with a new T-stat gasket its about 2-3 mm thicker on the stand pipe side to eliminate all leaks. I will keep you posted on what i find on the trucks.


There was also talk about a junk motor in the works. I think its allready on the road. VT-265 i think is what he said the name of it was. He made mention of something about the egr coolers and oil coolers developing leaks maybe mixing oil and water. There was some other stuff also, but i will have to see if the other guys in the shop heard what he said.

 

I just replaced my T-stat (203*) last week. No silicone, no leaks. I did purchase a new housing with the thermostat. I learned that here. I cleaned/scraped the old remnants off. I learned that here. I put the gasket/o-ring on top of the new t-stat. I learned that here. It was also mentioned trying an o-ring above and below the new t-stat. I learned that here. Didn't need to. Hope this helps.
- Ish

 

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You cannot beat it.

Bill