Radiator cap for coolant recovery tank

[Jerry Ward]

We have a 2008 Beaver Montessa with the C9 Cat engine and it has lost the radiator cap on the coolant recovery tank.  Looking for information for the correct replacement.

TIA!

[Steve Huber]

Jerry,
I replaced mine with a 13 PSi Radiator Cap  (Duralast 7013 or Stant 10229) at Autozone. I think the original was a higher PSI unit but there is no reason for a higher PSI, especially if you have a plastic surge tank.
Steve

[Carl Boger]

Jerry,

I replaced my plastic tank with one of the steel ones from Beaver Coach Sales.  The replacement came with a 16 psi cap.  I believe that my old cap was 11 psi, but that tank had already busted and had been repaired with epoxy.  I replaced it hoping to avoid a breakdown if  or when it busted again. 

[Jerry Ward]

Jerry,

I replaced my plastic tank with one of the steel ones from Beaver Coach Sales.  The replacement came with a 16 psi cap.  I believe that my old cap was 11 psi, but that tank had already busted and had been repaired with epoxy.  I replaced it hoping to avoid a breakdown if  or when it busted again.

Thank you so much!

[Jerry Ward]

So, I replaced the radiator cap and added antifreeze, it seems to discharge or leak out of the overflow tube of the recovery tank, even when it's cold.

[Eric Maclean Co-Admin]

Jerry
 check the mating service where the cap seats in the radiator for anything that would keep it from seating properly like dirt debris or even a crack .
Also make sure the cap seats with some spring pressure into the radiator and that the rubber seal is intact.

[Steve Huber]

Jerry,
Based on My 07 C9, if you fill the surge tank full when cold it will discharge over a quart when warmed up. Since the C9 is designed to run fairly hot (204+_) I added coolant recovery tanks. The tanks one gets at auto parts stores are not large enough to capture the overflow from the surge tank when the engine is at normal operating temperature so I put 2 tanks in parallel. They work fine. Just be sure they are level and at the same height so they fill and empty equally to prevent drawing air from one while the other still contains coolant. Connect a tee fitting to the surge overflow line and run connect a line each from the tee to each of the added tanks.
Steve

[Jerry Ward]

Thank you so much, Eric and Steve!