Outer Limits 4x4 Board

hey all
i have a 93 80series T/D diesel
i dumb fucket at the moment....lol
anyway my brake pedal goes soft and right down to the floor when the motor in running.. when the motor is not running its hard..
i have change the master cylinder bleed it all ..
check the vacuum all great
put the pedal is still soft and goes right to the floor still...
do you guy think its the brake booster??? i don't know what else it can be...

mate check all your wheel cylinders & calipers seals aswell and you might have to remove you wheels
cheers russell

and check the brake preportioning valve on the rear brakes if they arnt set right or if they leak it will give you drama aswell

so it did it before you changed the master cyclinder?

I doubt it would be the booster, when a booster is gone you have to do all the work yourself i.e its very hard to push down - like the motor isnt running.

I would be looking for air in the system, or leaking slave cylinders.

take your wheels off and look at them for leaks or if your lazy and dont think its the problem you can just do this - but its messyer if it is a slave cylinder.
have a look at your resevoir, mark the level with a texta, start the engine and pump the brake pedal a few times, re check brake fluid level, if its lower it leaking, if its not lower then its not leaking.

in which case its air in the lines. describe how you bleed the lines?

does that pedal get harder when you pump it? does it stay hard or slowly drop towards the floor?