Hi folks--hope someone here can help. I tried a search and came up empty.
A few days ago, I noticed some coolant on the grpund, coming from my 95 f150--300CI/4.9. I went to squeeze the upper hose to see if it would "spit" from where it was leaking, and found the hose to be hard as a rock (well, not THAT hard). I swapped out the radiator cap, but I still seem to have too much pressure in there. Someone also told me a head gasket could do this, but coolant and oil are clean (I know, fluids don't always seep).
I changed the rear main about 2 weeks ago, and pulled the engine to do all the gaskets (valve cover, oil pan intake/exhaust--NOT water pump or thermostat). Would accidently crossing heater hoses when putting the thing back together do this? Coolant was changed during the work and the thermostat was replaced last spring.
I was also told that air in the system might do this. If so, how would I "Bleed" it? Finally, why isn't the cap, rated at 13 lbs., releiving this pressure?
Any help would be appreciated, before I shell out an hour's worth of a mechanic's labor to pressure test/troubleshoot the thing. Thanks in advance. Oh yeah...hoses are new.

--jim

 

If it's your upper radiator hose that's hard, it's normally a sign of a stuck thermostat. 13lbs are usually only reached at or near boiling and the cap usually won't relieve the pressure once the truck is shut off unless it's really overheating. Not sure on the crossing of heater hoses, but where did the coolant come from? The cap overflow or the weep hole on the water pump?

I would pull that thermostat and boil it in a pan and watch for it to open. You should invest in a "failsafe" thermostat. You can buy those at Autozone.

 

thanks throttle,