1994 Ranger - Cooling System Question

Three extra PSI in the cooling system shouldn't cause a gasket to leak - if the seals and hoses were that sensitive they would pop left and right on people.

The bolt that is weeping might be a "wet" bolt, where the threads have coolant on the other side - check the manual. If so, you should only need to remove and reinstall that one bolt with some sealant on the threads, or (if all else fails) a copper washer under the head.

Mitchell says 13 PSI and Autozone says 16 PSI - One of them is probably right, but which one...? Tie breaker: Go ask Ford. ;-)

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"Joe" wrote: (1994 Ranger 4.0L )

AutoZone computer says 16 Lb. radiator cap is specified for my car, but Mitchell book says 13 Lb. Which is right? Will my 16 lb. cap have too much pressure and cause leaks that might not occur with a 13 lb. system?

I recently changed out the water pump. I used a torque wrench and tightened the bolts down evenly but I now see a leak at one of the attachment bolts. Could my

The water pump leak problem has nothing to do with the cap. Assuming that the pump gasket was not damaged at installation, the leak is probably water working its way past the bolt threads. Remove the bolt, coat the threads with sealant and reinstall it.

A pressure radiator cap is used to raise the boiling point of the engine coolant so that it remains liquid instead of turning to steam when heated. If the liquid flowing in the engine block turns to steam, its ability to carry away heat almost vanishes.

The coolant's boiling point is raised about 3 degrees per Lb, so a 13 Lb cap will raise the B.P. of (50/50) coolant from

The 16 Lb cap provides somewhat better protection from hot spots being developed in the head/block casting. The engine and the hoses can easily withstand the pressure.

I can't think of any reason to use the 13 Lb cap, but I don't own any cars with the modern plastic radiators, so I don't know how fragile they may be.

Good luck.

Rodan.