I agree with MPIRCE, most air brake rv drivers do not know how the system works, and are an accident waiting to happen. The only saving grace is that the air brake system is very reliable.
JWMII, the original post stated that he had 10 PSI and could not set the spring (park) brake, and had to chock the wheel. He did not know that the spring (park) brake automatically starts to apply at 40 PSI. The park brake valve is designed to release air and apply the spring brake at or below 40 PSI. I am concerned that while he now has air pressure the park brake system is very weak or nonfunctional. JT
