How long does it take for the pressure to drop in your system? I would think that if it takes 10+ minutes to get the pressure up to 60 psi with the engine compressor you must have leaked out most of the air in your system. My engine mounted compressor comes on at about 90 psi and will pump up to 125 psi before it shuts off. My 120 volt kicks in and out at lower pressures than my engine mounted compressor.
It takes a minimum of 60 psi for the air slide on the generator to operate. The complication of the air system on the Newell does offer multiple sources for leaks. The more air operated equipment you have the more complex the plumbing. Many Newells have air bags, air slide for the generator, air slide for the entertainment center/freezer in the bay, air slide for the stairwell cover, air operated dump valve on the passengers side, and on the recent models air operated doors giving many chances for leaks.
I don't think I have ever let my system drop below about 70 psi since I live in my Newell and keep the 120 volt compressor switched on all the time. However, when I start the engine, it does take a couple of minutes to bring the pressure from 80 psi or so up to 125 psi even if the air bags are properly inflated. When the air bags start inflating it takes a long time it the engine isn't on fast idle and several minutes even if it is.
With air brakes, neither of the compressors should be cutting off at 60 psi since 60 psi (or 1/2 of the compressor governor cutoff pressure on older vehicles) is the pressure that the low air pressure warning system should come on. Air brakes use a lot of air and if you are truly starting at 60 psi you have little safety factor for the air brakes. Start the engine and as the pressure starts to increase, see if you hear air escaping, particularly from the front of the coach. You may have a dump valve or a solenoid sticking in the open position. That will really slow down the tank pressure buildup.
|