BRAKES

[tassie wombat]

had crap brakes for years and i thought it was finally time to do something about it,pulled off all 4 callipers freed up all the slide pins and lubed up with anti seize,de glazed pads and rotors etc etc.pedal height is good,booster is working,but with the vehicle on jack stands,engine running at about 1000 rpm and in low range 1st gear(hubs locked) there isnt enough braking to stall the engine,next step is to bang on a new master cylinder,am i on the right track???

the car is an '88 gq with 4 wheel disc's,thanks

[04off]

Did you try and bleed any air out of the system yet ?

[tassie wombat]

Did you try and bleed any air out of the system yet ?

yep,bled it,couldnt get any air out,pedal is a bit spongy though!

[tassie wombat]

things are looking good! fitted the new master cylinder tonight,bled the system and on stands in low 1st(hubs locked) at 2500rpm,jump on the brakes engine stalls will see how it goes on the road tommorow!!!!!

[BadMav]

Any lift? Be sure to extend the LSPV bracket on the diff by the same amount.

[tassie wombat]

yeah its got 7" springs,and the bracket for the lpv has been lengthened.ive got the spring on the valve adjusted so that thevalve is hard on(full preasure to the rear calipers) the rears dont seem to do sweet FA!

[hokey]

so do you adjust that nut to tighten the spring to get more braking to the rear? i want more rear braking too but manual doesn't tell me which way to adjust it and don't really wanna fawk anything up ha

[tassie wombat]

so do you adjust that nut to tighten the spring to get more braking to the rear? i want more rear braking too but manual doesn't tell me which way to adjust it and don't really wanna fawk anything up ha

loosen the 2 bolts that hold the bracket to the diff housing and move it so there is more tension on the spring that goes to the valve.

[tassie wombat]

can anyone tell me if theres a differance in bore sizes between gq and gu master cylinders?

[MyGQ]

yes there is a difference bwtween GU and GQ. one is 25mm and one is 26.2mm

[tassie wombat]

fitted new rotors and pads,shit loads better,still wont lock up on road though,hopefully once the pads have bedded in they should be spoton!

[garth]

so do you adjust that nut to tighten the spring to get more braking to the rear? i want more rear braking too but manual doesn't tell me which way to adjust it and don't really wanna fawk anything up ha

loosen the 2 bolts that hold the bracket to the diff housing and move it so there is more tension on the spring that goes to the valve.

If you put more tension on the spring it will be the same as lifting it with no arm lengthening ie reducing the brake bias (less rear brake).
So wouldn't it be less tension on the spring to give more bias to the brakes? ....as that's what you're doing when lengthening the bias arm by the amount of lift you have put in.
GQ brakes have never been that good so I would be interested to know.....What ya's reckon?

[sw1]

stupid question, however you said it still feels spongy

are you bleeding the actual load valve as well?
they do have a bleed nipple