So, Ive been replacing lines and hoses each week and other parts on this old truck. Now Ive a pressure problem with my cooling system...
The guy I bought it from had stop leak in it but Ive replaced the heater core that was leaking and flushed the system twice..
My return radiator and sending hose gets super big and the cap ( new ) doesn't let off..
My auto book says might be wrong thermostat for engine..How do I tell if it failed water pump?

 

Well if the cap doesn't let off what are you worried about? They relieve it like 15 -16 psi.
It's got nothing to do with your thermostat.

More likely that thr previous owner had stop leak in there because of a head gasket leak

 

You probably shouldn't try to fix it anymore. Have someone help you with it.

 

Thanks Karen for your input! Good trolling!!!

 

My pleasure Felecia

 

Check the coolant for exhaust gases.

 

^this. Most auto parts stores have rental programs, you could rent one of those

 

No that's good too, no exhaust gases.. I'm hooking up to computer later today. And he's a Ford guy ... I do have a mis problem starting so it's just in time... Thanks