cooling system problems

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Aug 13, 2005 | 07:44 PM

baxy

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cooling system problems

1996 f150 4.9 5speed A/C

after a short while of driving the cooling system develops alot of pressure
the pressure actually caused my old rad to burst at the plastic tank seam and now it is pushing its way out the t-stat gasket

the upper hose is hard as a rock all the time, poor circulation throught the heater core
and the temp gauge always shows low like barelt to the fist notch maybe 1/8 inch up on the gauge
it has
new coolant
new rad 4 core
new t-stat
new belt installed correctly for A/C

I'm thinking it will probably soon blow up the heater core (ugly)

anyone come across this before

Aug 13, 2005 | 08:14 PM

Beechkid

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From: Southern California

Check to see if the new thermostat is defective...I would change it anyway even if it's new & secondly check the lower radiator hose to see if it is collapsing....in the old days they use to have wire inserts running inside the lower rad hoses to prevent collapse but those are almost gone.....sound slike a definite possibility to cause a large psi build up

Aug 14, 2005 | 08:52 AM

baxy

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done that I'm on the third t-stat with same problem
origional,1st replacement and 2nd repalacement

I'm not getting bubles in system but there does seem to be air in the system even after extensive effort to bleed it

Aug 14, 2005 | 09:21 AM

Beechkid

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From: Southern California

Probably time then to get some dye for the radiator and check for leaks (including possible head gasket) but I would rule out the lower radiator hose collapsing first.

Aug 14, 2005 | 09:30 AM

Spaznaut

Fleet Mechanic

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From: NE Tennessee

Those hoses would collapse at high rpm. If it has all this pressure at idle than its hard to tell. Anytime a system is hot its going to be under pressure. It depends on how high you rad. cap is rated as to how high it'll go before it'll release. You never did say what psi your cap was. If your heater core is rotted or weak it'll bust no matter what. Just ask all those that have had to replace em

. Sounds like you have a possible head gasket problem. However your cap shouldn't let your system over pressurize. Like a pop-off valve on a water heater. I think there are some posts around here on how to pressure test the system. I'm not familiar with em...yet.

Aug 14, 2005 | 09:42 AM

baxy

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cap is new ford stock replacement I think 14 psi
I'm going to get at the head gasket I think
just wanted to know if anyone else has come across this problem