Over the past 2 years I have put 2 radiators in my truck (85 f250 6.9L). The second one I am on now just sprung a leak. Weird problem though... I run the truck to operating temp, pull over, there is coolant leaking from the far left on the top tank. So I open the safety lever on the cap release the pressure and drive home. During the drive home NO coolant leaks out! Any help or advice? My dad seems to think it is a crack in the head gasket causing too much pressure in the cooling system.

 

sounds like your cap is over pressuring the system I believe there only supposed to be 8 psi cap.... safty caps start around 12... so too much...

do u have an aftermarket guage or are u relying on the factory guage....mine never goes above the N in normal ..... pull a pass it might get to the beginning of the r..... so I'm also gonna have to install a guage that I can trust as well.....

Get a cooling system tester the ones that check for exhaust in the cooling system... they work the best in this type of diagnostics I have found..... we have to use them in the dealership to warrenty an engine comming out.... to get paid for it anyways....

 

My cap now is 13 psi. I guess I will try a lower psi cap. I do have an aftermarket gauge as well.

 

IH used 7lbs, Ford used 13.

 

anyone know the part # for the 7 psi cap? And is it possible that a lower psi cap will stop the leak?

 

doubtful. sounds like shitty radiators.

 

that too...... are u using full metal ones ??? or are they plastic tank ???

 

I believe they are made of brass and copper. I think the are just garbage radiators. 3 in 2 years is kinda ridiculous. Spectra Premium radiators they are called.