brake problem with 94 GQ

[chook555]

I have just finished a holiday at Honeymoon bay and the dirt road was terribly corrugated. Now I always put the 94 GQ into 4 wheel high when travelling this dirt road but this time I drove over it I had trouble with the brakes in that I had to pump the brake pedal to get the brakes to work.
But when I get back on the bitumen and change to 2wd the brakes work fine, no need to pump the pedal. Get back on the dirt road, change to 4WH and brake problem returns.
Can someone give me some ideas as to what the problem could be.
Thanks in advance.

[RN]

How are your pads.

If they are down could the corrugations be allowing the brake cups to receed into the piston causing you to have to pump them back out?

[chook555]

RoadNazi,
Thanks for that I'll check them when I get home.

[bogged]

I have just finished a holiday at Honeymoon bay and the dirt road was terribly corrugated. Now I always put the 94 GQ into 4 wheel high when travelling this dirt road but this time I drove over it I had trouble with the brakes in that I had to pump the brake pedal to get the brakes to work.

We were warned of this at driver training.. apparently its caused by the pistons in the calipers being pushed back.. cant remember th cause, but it was 'an issue with patrols'... I never had a problem, but apparently it gets worse up on Cape York with corrigations..
pads would be first point of call

[RN]

I have one of those annoying sticky caliper problems on one of my discs. Sounds like I have run over 100 cats, ...very embarrassing

[bogged]

I have one of those annoying sticky caliper problems on one of my discs. Sounds like I have run over 100 cats, ...very embarrassing

easy repair.. caliper kit, or exchange caliper...... eitehr is easy repair.

[ashbilt]

dont go spendin coin on it, its got nothing to do with you bein in 4wd it is 100% to do with the corrigated roads as long as your concius of it, an you dont sit up someones ass while on the corrigated road brake early for corners an you'll be fine mate. i havent yet driven a vehicle that the brakes dont bleed back on when on extreme corrigations, mmm dunno if sounds right... every vehicle i've had on bad corrigations has bled back on me.

[patrol man]

sound to me like the front wheel bearings are a bit loose, check that first

[jessie928]

How are your pads.

If they are down could the corrugations be allowing the brake cups to receed into the piston causing you to have to pump them back out?

dont worry, all of the GQ's i have taken down to honeymoon bay ( target beach) do the same

its the corrugated roads.

I just pump the pedal a little at 500m intervals.

Jes

[NutterGQ]

check ya wheel bearings if there lose they will let the disc push em back while your on the rough stuff, walk out side grab the top of the front wheels and push/pull like a mad man, if you can feel or hear clicking there lose and thats half the issue.

[mavzilla]

its a real pain but ya they all do it(worn pins on the slides makes it a lot worse)watch the dips(cracker/big/cheese/stick)on the way to the cape with it as you get a sore head