I realize that this is a 6 month old topic, however, I was asked about my auto park brake conversion design on another site and a search on the Chevy/Workhorse P30 auto park brake failure problems brought me back here.
This is the fix I did in a redesign of the auto park brake actuator:
I solved the Chevy P30 Auto Park Brake failure problem. (I think I also posted this here 2 years ago when I did the redesign conversion.)
Others have done my conversion redesign on their auto park brake units and resolved their failure problems:
Others who have used my solution and solved their Chevy Auto Park Brake failure problems. (start at post number 1)
My redesigned auto park brake unit has been installed and working for 2 years now, it works just as the factory design works ... except it works better - no failures! (the failure mode has been removed) and it holds better on grades! (holds on the steepest grades I have tried so far ... a 10% grade).
