Coolant coming out reservoir and WP leak

[Skman]

(05-05-2018 )Brock Wrote:  The bubble test will only show the compressor to be the issue if the compressor is building air. Make sure your cap is on and run your hose from your overflow tube. Problem is the PACCAR pressure relief caps are 13 psi caps so you need to let the system build over 13 psi before the bubble test would even start.

Let the truck run a while and get nice and hot, then if it starts bubbling pull the air output line off the compressor (line to air drier) and see if it still bubbles. Your compressor will constantly run with that line off but that's fine.

If when you warm up the motor and do the bubble test, it doesn't bubble.... Press the brakes a bunch to lower your air and get your compressor kicking in and then look to see if the bubbles are present.

I took an extra coolant tank cap and tapped a pressure gauge into it. Ran the engine til it was warmed up and run it through different RPM ranges up to 1400 and couldn't get more than 12lbs of pressure on the gauge and never moved over into the overflow part of the tank.
I also pumped down the brakes and checked the pressure gauge with compressor running and no change...12lbs.
Next morning...my driver starts the truck and warms up a few mins then drives about half a block to the cardlock to fuel up...and it's pissing out the pressure cap already.
I'm grabbing a water pump tomorrow in Lloydminster and will change that at least once it is leaking. It started leaking at the same time that this coolant tank issue started.