Reply To: The 1935 845 Pierce Arrow

[Jim Chase]

I can’t speak to the operation since I am only to the point of being able to run mine in and out of the garage – although I am pleased with a system that stops as well going in reverse as it does forward!

In terms of longevity, my 845 apparently had 55000 miles when it was retired and left to sit after WWII. When I dissassembled the power brake unit the soft woven clutch material appeared to have no wear, was in good shape and I just put it back in. There was a spot of very minor surface rust in one area of one of the pressure plates that I easily removed with very fine sandpaper to match the original surface finish. I think the key to longevity was maintaining transmission oil in the system that keeps the liner wet and lubricated. I imagine the most likely problem is leakage of the seals around the brake output shaft that would drain the transmission. The many PASB messages over the years seem to indicate the friction characteristics of the clutch material are very important to how the unit performs including whether it wants to creep at a stop. For this reason I was relieved that mine seemed to be in excellent shape and didn’t need replacement with some other material which inevitably will behave differently to some degree. If the liner is shot of course, one has no choice.

If the pressure plate faces are damaged, I would expect that turning them accurately flat and replicating the original surface finish would be very important. Theoretically speaking, too course a finish would tear up the liner quickly and too smooth might reduce the braking power.

Jim