If you own a motorhome with air brakes you should test the system to ensure that everything is working properly. Do you know how? There is a standard test used to check an air brake system for proper operation. Note: Before you start the test you should chock the wheels.
You first start the engine until you hear the compressor cut out, that sound you hear when the relief valve lifts. This should about 125 psi.
You then shut the engine off and watch the pressure gage(s) to check for leaks. The pressure should not drop more than 2 psi. in one minute.
The next step is to turn the ignition switch on, but do not start. You then release the parking brake and depress the brake peddle. After the initial drop it should not drop more than 3 psi. in one minute.
You would then pump the brakes until the warning buzzer and light come on. This should occur at half the compressor cut of pressure, which should be 60 to 70 psi.
The next step is to continue pumping until the emergency brake “pops” up. That should be between 20 and 45 psi.
After all this you start the engine and watch the pressure build up. It should take no more than 45 seconds to build from 85 psi to 100 psi.
Remove the chocks and then put the coach in gear with the parking brake on. Apply just enough throttle to see if the coach torques, but not move.
The last step is to release the parking brake and accelerate to 2 to 5 mph, then firmlyA apply the brakes. The coach should come to an immediate stop with out pulling to one side or the other.
I would suggest performing a test at the start of every trip, or at least annually.