Questionhave changed master cylinder,buster,vac pump and when engine is off pedel is hard as soon as you start pedel go to floor
AnswerHello.
Is this a continuation of a prvious question?
Ther brake pedal should drop as the vacuum builds, but not to the floor,
Are you losing fuid?
Is the brake warning light on at any time?
Does the light work?
Did you replace these parts to try to repair this problem? or is it a new problem?
Lets assume that you are trying to fix this original problem.
The brake pedal dropping when the engine is started, indicates that the vacuum pump and booster are working.
The fact that the pedal only drops when the engine runs, indicates that extra pressure is required to push the pedal to the floor.
Does light to medium pressure with engine off cause any pedal sinking?
pinch the from brake hoses and try it again, than try the same with the rear hose.
You may be able to isolate the problem to one axle or the other.
Seized braking components, over sized drums, swollen shoes or pads, leaking axle seals, small leaks, air in the system and bad hoses can all contribute to this problem.
let me know what you find please.
