Never could really tell if my Pac Brake worked.
A neighbor in a campground last week with the same system showed me what to test and suspect was most likely wrong. I ordered a new Humphrey valve seal and o-ring.
Cleaner's Supply, on the net had the seal and o-ring for $ 7.95.
When it arrived I headed to the coach and removed the plug nut on the Humphrey valve and found the seal destroyed. Installed a new O-ring on the plug nut, and the seal from the kit. Was a good guess, but could have been tested before ordering parts, but he told me I would want a spare if my seal was good anyway.
With Bill Chaplin overseeing I plugged in a wall converter that makes 12 volt. Powered the wires of the solenoid that activates the Humphrey valve, allowing air, that in turn pressures the air cylinder that closes the exhaust flap. With air in the tanks, everything worked as it should.
I should have ordered a second as a spare. The info I got from the other Pac Brake owner was, his worked one day, not the next. Seeing how small and thin the seal part is, easy to see how that could happen.
We also found my valve works anytime the switch on the dash is "ON". Nothing more required, like off throttle, or on brake, or certain rpms. It works at idle, and causes a change in engine speed and exhaust sounds noticeable with the bed raised. Learned not to drive with it "ON".
Of course all you owners with either Jake Brakes or retarders can ignore this repair.
Next is to replace the 2 broken or non working compartment lights, 3 just arrived at the door, along with a dog biscuit for Clare.
The extrader brake should release as soon as you press on the accelerator. If it does not you stand the chance of blowing a head gasket and messing up the turbo pressing on the accelerator with the switch on. There is supposed to be a switch on the fuel pump that releases the pack brake when you press on the accelerator. Mine was missing so I added a foot switch. My post under this topic of 9/9/2012 explains what I did. It is easy enough to check if it working correctly. Just have someone watch the actuator as you give it some fuel. If the switch is not working you will get Aton of black smoke coming out of the exhaust.
Roland
Roland,
Thanks for the warning, I need to lift the bed, and get someone to advance the throttle and see what happens. I understand that the valve should open when something happens up front.
I went back and read your switch install, and will add that to my list.