i have been digging around, trying to figure out why my t-stat housing has been leaking.
was leaking before i put new t-stat and seal in:
3283589 thermostat
3923331 seal

it continues to leak

in a few places i have seen this part number for a t-stat seal/gasket...
3920336 gasket/seal
is this gasket/seal the one i got circled in the exploded diagram here?
picture is from alldata...

TIA

 

I've never seen 2 seals in there. Only the 1 thick one.

Check out this sticky thread.
https://www.dieseltruckresource.com/...d.php?t=146039

 

Here is the one I used #3923331



Here are some more pictures of the thermostat and housing.

https://www.dieseltruckresource.com/...6&postcount=10

Jim

 

I had a parts store try and sell me that 2 peice seal once. I didnt buy it because it looked nothink like what I had or had seen. Try going to a different parts store and get the one peice seal.

 

The one pictured by the op is of a 94-98 12 valve 2nd gen truck.

 

interesting...
well its all coming apart again anyway.
jim, i have the seal you have in the picture. i picked the t-stat kit up from valley freightliner using my engine number...
the picture i posted is from alldata. selected 1993 dodge w250 diesel. and to double check i looked at the info for a 1992, same picture.

if it comes off again after that... im putting some of my magic locktite flange sealant on the housings and calling it good. it wont leak after that.

 

Fail on alldata.

 

interesting.
oh well. i paid a visit to the local freightliner and cummins northwest and poked around asking questions. picked up a few things i need and away we go. this **** thing aint gunna leak when im done with it.