I have a 1989 F 800 Diesel Manual Tans Disc Brakes on front Not sure what the brake system is but there is a motor that runs when the ignition is turned on. THen the parking **** is pulled, it puses the brake pedal out...
Where can I find information ont his system ..not sure it is functioning properly. When empty seems to work great but when loaded have trouble stopping sometimes.
Love the dump truck as it gets excellent mileage and has tons of power...
The electric motor should turn off once the engine is running. The pulsing is usually the bypass pressure building then relieving.. Its normal as the system gets older it is more and more noticeable. I tried and tried to get mine to stop doing it and I ended up just letting it be.
As far as braking power you should check that your rear brakes are adjusted.
Jack the tires up off the ground and adjust them out until the tires is locked then back it off until you can just barely hear the shoe rubbing on the drum.
And obviously check the fluids. Brake fluid and hydraulic fluid. Its also possible that the pump is going out? If you get the right guy in the service dept at ford he may tell you what the pumps pressure should be. You can get a gauge on there to check to see if youre in spec. Some of the pumps have a filter in them that may have gotten plugged with gunk.. If there is a bolt head on the top of the reservoir you can pull the reservoir apart and clean the screen. If there is one.