Lehman "Radiator" cap

[ARoss]

Routine inspection, unscrewed the cap on the coolant tank, and the thermostat spring was separated from the housing. Took a little fiddling to get it all back in place. Is this a unique part? Looks like an auto radiator cap; can anyone give me specs on the thing?

 

[Marin]

The thermostat on an FL120 is in the chamber below the expansion tank. It's not in the expansion tank "radiator" cap. You can get replacement caps from American Diesel or I've been told a Detroit Diesel cap will fit. Make sure you get a cap with the correct pressure release rating.

 

[rjwilliams11741]

Expansion Tank Cap

As Marin said that is not the thermostat as the thermostat is located on the bottom of the tank. It is simply a radiator cap and you can use any
7 psi automotive cap and it will work fine. Just go to you local NAPA store.

 

[BruceK]

It is simply a radiator cap and you can use any
7 psi automotive cap and it will work fine.

I understand the original cap was 4psi. After the filler neck was redesigned the cap was 7 psi. That`s still fairly moderate,but a big % rise on the original.
Anyone see a problem using a 7psi cap on the original design? BruceK

 

[rjwilliams11741]

Filler Caps

I did not know that the older design filler neck used a 4 psi cap. My filler necks were upgraded by the PO. The newer design necks can be identified by the fact that some kind of epoxy compound was used to seat them into the expansion tank.

 

[BruceK]

I did not know that the older design filler neck used a 4 psi cap. My filler necks were upgraded by the PO. The newer design necks can be identified by the fact that some kind of epoxy compound was used to seat them into the expansion tank.

I only learnt of the 4 psi cap emailing American Dsl about new ones. My necks look unmodified, caps need replacing. May chase 4psi ones here(lowest so far is 7),if unavailable, need to choose between 7 psi or ordering from Amerdsl in USA. BruceK