I am changing the hose that is between the water pump and the thermostat housing.
there is a washer with a hole in the middle.
what is its purpose.
does it supposed to be there
thank you
Yes, you need to put that washer back. It's purpose is to restrict water flow in the system. I think it helps to bring the water temp up faster.
ok but then how do you cool it down.?
on my last long trip it took longer to bring the temp down
That washer is there for the retarder cooler to operate properly put it back where you found it.
Mike
Here is a link to an old thread that has some info out of the Cummins book.
Still running hot (https://www.foreforums.com/index.php?topic=34240.msg314542#msg314542)
Mike