Pressure in radiator & into overflow tank??

[MarkofCobra]

Please help !!
My 90 7.3 IDI is building a lot of pressure in the radiator, past the cap and into the overflow tank? I can hear it blowing into the overflow tank. This happens within a couple of minutes of cold start. I'm afraid if I drive it, it will blow all my anti freeze out of the radiator. I noticed that for the last couple of weeks I have been adding about a gallon of coolant about every three days? Would it do any good to retorque the heads? Any help would be appreciated. Thanks.

[chuckster57]

It might be head gasket failure, and if your getting that much pressure that fast, then a re torque isn't gonna help. I would do a pressure test of the cooling system first. If it passed that test then there is a test kit that detects exhaust gas in the coolant.


Sent from my Autoguide iPhone app

[trampsdieseltruck]

Markofcobra i am having the same problem and i replaced the rad cap with a ford 16 lbs rad cap($9).it fixed the antifreeze to overflow problem but now my rad hoses looks like they are ready to blow! Chuckster could a bad t-stat cause this?

[chuckster57]

I suppose anything is possible, but I kind of doubt it. How old are the hoses? Have you removed the cap and then started the truck and watch for bubbles?

[trampsdieseltruck]

no i never checked for "bubbles".are they from exaust getting into the antifreeze? im waiting to see what "MARKOFCOBRA" has found out about his truck since this is his thread.

[chuckster57]

Yes, if combustion gases are getting into the coolant it will add pressure to the system. There is a test kit that you can get, but you have to use a different fluid with diesel engines. IIRC you can get it at Napa.


Sent from my Autoguide iPhone app