power brake problem

[rhuggett]

I have just experienced a total loss of power brakes as well as power steering on my 1992 Class A motorhome. It has a P30 chev chassis with an automatic brake application when it is placed in the "PARK" mode. I have recently had the master brake cylinder replaced (apparently the brake fluid was contaminated) and a minor leak was repaired at the power pump. The power pump was cavitating and not powering things properly. My mechanic has tried replacing the pump with no improvement and now thinks that the automatic brake may be the problem, and is going to try and disconnect it from the system. Has anyone had this type of problem, and how did you solve it?
I am a new member to the club, and I hope someone can help. Thanks.

[CLIFFTALL]

Welcome to irv2. I've moved your thread here to our Workhorse and Chevrolet section to try and get you an answer.
Cliff

[edgray]

Originally Posted by rhuggett

I have just experienced a total loss of power brakes as well as power steering on my 1992 Class A motorhome. It has a P30 chev chassis with an automatic brake application when it is placed in the "PARK" mode. I have recently had the master brake cylinder replaced (apparently the brake fluid was contaminated) and a minor leak was repaired at the power pump. The power pump was cavitating and not powering things properly. My mechanic has tried replacing the pump with no improvement and now thinks that the automatic brake may be the problem, and is going to try and disconnect it from the system. Has anyone had this type of problem, and how did you solve it?
I am a new member to the club, and I hope someone can help. Thanks.

Welcome to iRV2 and the Workhorse forum.

For ALL issues related to the J71 AAPB system that GM used on your P32 chassis you can get free and expert help via email to Roger at : oldusedbear11@charter.net. He maintains an extensive library of info and can help you and your mechanic figure out what is wrong. Good luck.

[DieselTech39]

Glad you're aboard. There are a number of threads about the J71 AAPB here too. Type it in the google window on the tool bar above and leave it set to IRV2. Sure you'll have plenty of reading. Best of luck on a solution. Enjoy your adventures and be safe.