StuckAgainSteve
Well-Known Member
The Hydraulic Boost Pump and Accumulator store pressure for use in the braking system....
Consider the system in 2 halves - Pressure Storage Side and Brake Components Side - seperated by a valve (the Brake Pedal)...
When you press the brake pedal this allows pressure stored in the Accumulator to boost the Hydraulic Pressure required to activate the brakes, when you come off the Brake pedal, it vents this pressure back to the Fluid Reservoir, and closes off the Boost circuit....
When Accumulator pressure drops, the Hydraulic Boo5st Pump runs to recharge the Accumulator Pressure.
Unfortunatly, if the pump dies or the accumulator gets weak, braking efficency is greatly reduced.
Grit Valves description is wrong, the boost pump does not circulate through the braking system constantly and as such cannot be used to bleed the brakes....you will need to activate the brake pedal to allow fluid to flow....else, as you say, the brakes would be on constantly from the Pump pressure!
Thanks, that's exactly how I'd expect a "power brake" system to work.