hydro asst hydrolic brakes

[fallsman]

why assist pump energizing when no brakes applied

[magnakansas]

is called Hydro max hydraulic boost made by bosch/bendix

There are sever places on the internet to read about how the system works and you may find the answer to your question there.


william

[jazty]

Fallsman: you didn't provide much context. Is the electric pump always running? Even when the bus is running and also when the key is removed?


The expected behaviour is that the pump is continuously running when the key is turned to "run" and the engine is not running. Also, with the ignition off the pump will run when the brake pedal is pushed.

[BlackJohn]

Have a look at your brake switch where it contacts the pedal mechanism.

It is probably making contact there. You need to adjust it so there is a small gap so that switch makes only when the pedal gets pushed.
That will stop the pump from running endlessly.


John

[golfersmurf57]

Originally Posted by BlackJohn

Have a look at your brake switch where it contacts the pedal mechanism.

It is probably making contact there. You need to adjust it so there is a small gap so that switch makes only when the pedal gets pushed.
That will stop the pump from running endlessly.


John

The electric pump comes on if the key is on and there's no flow from the engine driven p/s pump there's a flow switch and relay that control the aux motor. It will run in key on engine off mode as well. You can get testing info on Mitchell heavy duty so your local truck bus shop may be able to print the pages for you. Usually you're out of steering fluid due to leakage or your belt is not turning the pump -loose or not on.