Henry J Fate
Well-known member
- Joined
- Jun 14, 2018
- Posts
- 2,292
Hello everyone. Hope all is well
2001 Winnebago brave 32 ft class A workhorse chassis with the auto park brake.
Yesterday I pulled up to a camping parking spot and engaged the parking brake while I reviewed the area to safely back the coach in. After a minute or so I released the brake, pulled slightly forward then put the transmission in reverse and began to back the coach into the space. I was half into the space and half out when I heard a motor running so I put the coach into neutral to get a better idea of what I was hearing. It turned out to be the auto brake pump motor. Still in neutral I set the park brake then released it. After fully releasing the motor came back on about 2 or 3 seconds after initially shutting off. The brake appeared to be fully released so I continued backing in. The motor popped on and off a couple of times during the 5 minute parking sequence but eventually stayed off. This was the first time any abnormality of the parking brake was realized. I checked the reservoir it was fine and I found no evidence of a leak however today I will crawl underneath to examine the hydraulic line that services the park brake. Last night I reviewed the park brake system and found that the pump assembly appears to be turning the pump on/off based on it being energized turning on at about 1200psi and off about 1400psi. When pressure is in this range the park brake is released. To engage the park brake designers use a solenoid valve that is energized by either placing the transmission into park or pulling the actuator switch on the dash. Once the solenoid is actuated it releases the 1200-1400psi in the line and returns the hydraulic fluid back to the reservoir.
I guess it could be several failures but I am curios to know if any members have had a similar occurrence and what remedy was used. Also I reviewed a modification to the parking brake system which basically requires a 12 volt activating source to energize the brake in addition to releasing it. The factory design energizes the solenoid to release the brake and applies the brake when the 12volts is switched off.
Thanks everyone
My new plumbing layout has worked as I designed it to. The adavents have become inactive now that the tank vent is always available to take in air when dumping and release air when waste water is filling the tank
Henry
2001 Winnebago brave 32 ft class A workhorse chassis with the auto park brake.
Yesterday I pulled up to a camping parking spot and engaged the parking brake while I reviewed the area to safely back the coach in. After a minute or so I released the brake, pulled slightly forward then put the transmission in reverse and began to back the coach into the space. I was half into the space and half out when I heard a motor running so I put the coach into neutral to get a better idea of what I was hearing. It turned out to be the auto brake pump motor. Still in neutral I set the park brake then released it. After fully releasing the motor came back on about 2 or 3 seconds after initially shutting off. The brake appeared to be fully released so I continued backing in. The motor popped on and off a couple of times during the 5 minute parking sequence but eventually stayed off. This was the first time any abnormality of the parking brake was realized. I checked the reservoir it was fine and I found no evidence of a leak however today I will crawl underneath to examine the hydraulic line that services the park brake. Last night I reviewed the park brake system and found that the pump assembly appears to be turning the pump on/off based on it being energized turning on at about 1200psi and off about 1400psi. When pressure is in this range the park brake is released. To engage the park brake designers use a solenoid valve that is energized by either placing the transmission into park or pulling the actuator switch on the dash. Once the solenoid is actuated it releases the 1200-1400psi in the line and returns the hydraulic fluid back to the reservoir.
I guess it could be several failures but I am curios to know if any members have had a similar occurrence and what remedy was used. Also I reviewed a modification to the parking brake system which basically requires a 12 volt activating source to energize the brake in addition to releasing it. The factory design energizes the solenoid to release the brake and applies the brake when the 12volts is switched off.
Thanks everyone
My new plumbing layout has worked as I designed it to. The adavents have become inactive now that the tank vent is always available to take in air when dumping and release air when waste water is filling the tank
Henry