I have a slow seeping leak and can't seem to pinpoint where it is coming from. I suspect it could be the thermostat housing or one of the hoses, but it does it when the truck is just sitting, colder than a well diggers butt. Could I have a cracked block or a bad freeze plug?

 

I had a slow leak on my '89 F150. Was the little vent hole under the water pump, usually when a water pump leaks from there, it's time to replace 'em.


I kepted driving it, dripped slowly like that for almost a year, untill one night coming back home, as I turn into my street, I hear the belt start squeaking, and in the driveway, the water pumped just puked everything out.

 

My '89 had a seep, but it was the timing cover, bottom passenger side under the waterpump passage. Seems the gasket went south, the alumimun cover got corroded and leaked/seeped real slow.

I had to pull it all down, new gasket(put a new chain in too), water pump and all the other little pieces that needed replaced along the way.

 

If youve changed the water pump lately. There are a couple of bolts that go into water jackets. If youll pull them out and put sealant on the blot threads and reinstall them it should stop.

 

Put a pressure tester on it and have a good look....

 

No new water pump. I think the water pump is fine, I am going to reseal the thermostat housing and put in a new thermostat.