coolant loss

[grantj]

Before I started tearing things apart needlessly (I like to do things the hard way), here's what's happening with my 52 M38.
After driving my jeep, I always have to add coolant into the rad. As much as 1-2 quarts/litres or 3 when it was really low..
I don't see a puddle of coolant on the floor/ground after driving, but it must escape somehow. Maybe when driving til the level is too low?
Compression ,dry test shows 100psi. wet 110. No signs of coolant in/on the oil dipstick or around the head gasket.. I tried a leakdown test, it didn't show bubbles in the rad neck. (I may have not it all cyl right at TDC, which is hard to do). It looks like I may need to check the valves..
My temp gauge does not work, though it and the sending unit are new. For that I ran separate grd wire for the gauge and instrument panel.
My engine was rebuilt 9 years ago (by me), the head gasket has been replaced at least once since then , for other work. As well as the thermostat.
Any ideas? water pump, clogged rad? pressure test the system?
I have a big road trip in one month and don't want overheating problems..

[wesk]

The loss of coolant can be several things. Start with a check of the pressure cap. This requires the use of a coolant system pressure test set.. Then if the cap is good we pressurize the radiator to 4.5 pounds and see how long it takes to leak down. If this is less than 1 pound per minute she's probably ok.

[grantj]

Well, fix one thing and then another bad thing happens.. A week ago I replaced the rad cap, one from NAPA 31-307, a 4#. It has been fine til today. I have coolant coming out of the bottom of my water pump and through a head bolt (the rear lifting ring). Being the correct cap psi, there couldn't be a overpressurizing of the system? Merely pointing out the other weaknesses.?
I'm guessing a new water pump gasket and head gasket are to be done?...#@$%@...

[wesk]

The water pump leak may be coming from the seal weep hole on the bottom side of the nose part of the pump. This is hidden from view and you should use an inspection mirror to ascertain the leaks source is either this weep hole or the pump to engine gasket. If it is the weep hole you'll need a new pump or a kit to rebuild yours.

In your first post it was obvious that you had been running your cooling system unpressurized for years. Had you had that 4 Lbs of pressure 5 or 6 years ago you would most likely have had these leaks 5 or 6 years ago.

The head bolt or stud can be removed, clean both the male and female threads. Apply a good sealant like Permatex #1 to the threads and reinstall. Re-torque the entire head in the correct sequence.

[grantj]

thanks for your suggestions, Wes... I hope that the bolt sealant will do the trick instead of taking off the whole head..And I'll look for that weep hole..grant