Elusive Coolant Leak

[Radar12158]

Can't seem to pinpoint a coolant leak on my 97 Ranger,2.3 5spd. The water pump is dry. Same thing for the thermostat hsg and upper hose. In the morning I have a few drips of coolant under the front of the motor and a drop hanging off the bottom of the crank pulley. I can pump the cooling system up to 15psi. and not get a drip out of it... Is anyone aware of any freeze plugs on the front of the motor or any issues with head gaskets leaking at the front. Ive got about 240K on the truck.

 

[Mark_88]

Water pump seal? There is a weep hole at the bottom of the water pump (on the older ones, anyway) and if the seal inside the pump is wonky it will drip out of that weep hole...you probably won't notice it because the hole is small, but it drips right on the crank pulley...

If you wrap a rag around the nose of the water pump at night, check it in the morning...if it is damp, then the seal inside the water pump is leaking and you need to actually replace the water pump to correct this...or tear it down and replace the seal yourself...never did it, but I've had that seal leak on my Zuki and my first Ranger...

 

[RonD]

That would be my guess as well.
Water pump seal, it often won't leak as much with engine off.

Try doing the pressure test on cold engine while it is idling.

And FYI if pressure goes up you do have a head gasket issue.