8930 Magnum radiator cap

[SEMN]

I got a new radiator cap for our 8930 Magnum from our Case IH dealer. It is the cap for the actual radiator not the deaeration tank. I looked up the part number (253858A1) from the Case IH website and ordered it from the dealer.  The new cap that I got from the dealer is the part number I ordered but it is just a sealed cap with no springs. The old radiator cap has springs on it and says 15 psi. The old cap is what was on the radiator when I bought the tractor 10 years ago.  I believe the purpose of the deaeration tank is to keep air out of the radiator by keeping it full and I thought the springs in the radiator cap regulated that. Can anyone tell me if the new cap without the springs will work correctly?

[SDman]

That is the correct cap for that application. When the Magnums went to the deaereation tank setup on the 8900s, the cap on the radiator itself is just there for filling the radiator/cooling system. There is no provision for a radiator cap to relieve pressure to go somewhere else in that location.....no nipple so that when the cap opens it can go to either an overflow tank or drain it down the side of the machine. The pressure cap for the system is on the deaereation tank itself.

I'm guessing someone put a regular radiator cap there in the past for some reason. Looks like the proper one on the deaereation tank only calls for 10 psi. If that's the case, the one on the radiator that's rated for 15 psi should never open anyway.

[SEMN]

Thank you very much for that information. I will use the cap I got from the dealer.