Outer Limits 4x4 Board

Hey everyone, Ive got a 84' MQ Shorty SD33T and having problems with the brakes. While the cars off if I pump the brake pedal there is solid compression, but when the car is on the only way to get brakes is to pump the pedal a few times to make compression then there is just enough braking power to slow the car down, but if I dont use the breaks for about 4-5 seconds there becomes no compression again. If anyone can help, much appreciated.

can yoo pull the car up with a single press of the brake pedal, or does it just feel more soliderer with the engine off?

Are they a drum brake rear? Sounds like your rear shoes need adjustment/replacing, could be a naff rear slave. Drums should auto adjust, but as they age, the ratchet system in them starts to fail, and if you have a slight fluid leak as well then that just gums everything up and it's not very fun any more.

Drums are easy but fiddly to work with.

Front Disc, Rear drum. A single push of the pedal hits the firewall but 3 or 4 pumps and i get some breaks back for a couple of seconds then looses compression again. The brakes used to be fantastic but havn't driven it much in the last few months and now the brakes have this problem..

I had a similar problem with mine, i dumped all the brake fluid, done a full line bleed, all good now.

If your pumping it and regaining pressure then its one of 2 things air in the line so bleed your brakes or your brake master cylinder is gone

sounds like your rear brakes need adjusting or your muster cyclinder is no good

one of two things........

1/
Leaking master cylinder
to test.....
start engine
pump brakes till pressure is obtained
hold brake down as if heavy braking

if brake pedal slowly falls to the floor - replace master cylinder



2/
Rear brake adjustment
to test
jack up rear of vehicle so both rear wheels are off the deck
get an assistant to apply the brakes (no pumping) & hold the pedal down
try and 'spin' the rear wheels by hand (they shouldnt move)

if they move..... give a pump on the pedal and repeat the spin test

If it takes several pumps to stop the wheels from turning then adjust the rear brakes..... (done with a screwdriver through the slot in the brake backing plate)