Technical Tips #28
By Bob Lowe BOA #696
While some of you have a Chevrolet/Workhorse Chassis, the following information may be of use not only to you, but also to many which have a Bounder on a Ford Chassis. Early Ford OEM (Original Equipment) Brake pads were good but not the best quality and they did tend to deteriorate from 'use' and then 'extended sitting' (typical Motorhome use). With moisture in the air or inclement weather, the pads stick (rust) to the rotor. In extreme cases they form a firm bond with the rotor and when the wheel moves again, the pad stays attached to the rotor and breaks lose from the backing material. In less serious cases, part of the pad fractures and begins to disintegrate. Since brake tolerances are tight, the pad material cannot "fall away" and these pieces begin to vibrate, giving the noises many complain of. Not only that, but these pieces now provide even more surface for the water to invade the pad and the process continues. What is truly amazing is that the brakes still work at all.
However this braking comes at a price: less heat transfer and more heat buildup in the caliper, which will boil the fluid. Usually the fluid has not been changed (as recommended by Ford and GM) and since over time the fluid does absorb water, when this heat rises in the caliper, steam appears in the fluid and you have no brakes. Even if you regularly lubricate the caliper slides the caliper may still "stick" to the rotor. The solution is move the rig monthly or even more often in high humidity conditions.
The repair involves installing FORD brake pads, which have been upgraded for the 1998 and newer chassis, carefully examining and cleaning the glide pins and if there is any non-removable corrosion, replacing the glide pins. Further work involves changing the brake fluid every 2-3 years no matter what, with Ford Heavy Duty Brake Fluid (even on Chevrolet/Workhorse Chassis). It is the best compatible fluid and is made by the company that supplies the Ford pads. This company is active in high-speed car race supplies. You can move up one further level to a semi-metallic brake pad and even better brake fluid (without changing to non-organic synthetic fluid). These give a stiffer feel to the pedal that some may find objectionable, they may rust easier, however the more they are used, and the hotter they get, the better they work. They stop faster as they heat up. I have gone to this last step and have committed to moving and driving the coach monthly, no easy feat in a Canadian winter.
After having regularly serviced (some would say over-serviced) my brakes, and then suddenly not having brakes while traveling on the highway, I had the opportunity to learn a lot about these problems. My source was a Ford Dealership mechanic who recognized that many motorhomes were arriving at his large truck dealership, with very little wear on the brake pads and yet the brake pads required replacing. Hopefully my presentation of his solution will help you and many others. I cannot emphasize enough the care and lubrication of the brake caliper slides, regularly replacing the brake fluid and avoiding long periods of down time with the Bounder. If all took these precautions, many less people would be experiencing brake problems or worse.