Pass or Fail?

If I am correct. The way to test is to chock wheels, or make sure truck won't roll. Make sure brakes are released. Disconnect red (emergency supply line). A rush of air should come out. Watch psi and see what psi the button(s) pop out. Thats the way NY Dot checked mine. Other ones wanted me to pump my foot valve to death to lose air, to pop them out. I told officer about that and he said thats the incorrect way. Of course thats his opinion . Made sense as it is more of a sudden loss of air. I cringe wearing my foot valve out for this check anyway. Other lives and mine depend on that valve. At least not all Dot checks don't ask for this nonsense test. I have low air warning lights and buzzer, I can pop them myself if needed.

 

Pump down test is perfectly valid.

 

pump test is only right way as soon as red valve pops red hose doesn't have air so cant check the yellow valve that way but seems like when they check they wait for the bell and the trailer valve to pop and then have you start it to see how fast air comes back then on to something else ...... as long as the secondary or primary tank has 25psi the brake shouldn't pop on tractor but anywhere between 20 and 30 will pass a dot. and you would have to pump the brake about 5 million times to wear that valve out and it is designed to fail and engage brakes .... still have hand valve and emergency

 

There is one more test I recall.

Release all brakes and then apply service brake and hold a minute.

There should be a small drop from primary and secondary but that should stop in a few PSI and remain steady.

 

I understand that. Red shuts off air loss. I know that foot valves get pumped millions of times, but it still chaps me. It is a wear item. I just told about how that one Dot officer checked it. Done quite a few of the other way. Heck I pulled trailers when they didn't even have maxi brakes. Funny I survived. Mayby you know more about the foot valve than I do. The hand valve will be as worthless as the foot one if you have no air pressure. Some trucks don't have a hand valve.

 

The low pressure warning has to activate at 55psi and below or 1/2 the gov cut out pressure whichever is less by regulation 393.51, not 60 psi as in the CDL manual. The CDL manual is not consistent with the regulations.

 

No not really. But he didn't waste any time. Stepped up on truck and poked his head to take a look. Gave it his blessing.