gq patrol brake problem

[patrolmuddar]

just need some ideas here ..been having a few problems with the braking system all started with blowing brake lines out . got that sorted then kept losing pedal realised had a leaking caliper.. fixed that then problem persisted .. replaced master cylinder and still have problem.. i get the system bled properly and all working fine and after about 5 hours of driving pedal starts disappearing until it goes to nothing am out of options .. any ideas?

[patrolmuddar]

someone? anyone? desperately need to fix problem as i start a new job on friday and need own transport!@!@!@!@!@!@!@!@!@

[taslucas]

Sorry mate I don't know much about the brake system. Hopefully someone will be along that can help. Have you had any luck with any old threads?

Tap, crackle, pop

[BigRAWesty]

Well I'm stuffed to..
Did you replace master cylinder with a new one?

It can't be a vacuum problem, that usually makes the peddle harder but they still work..

The only thing I can think of is re- bleed the whole system again. And put a lot threw, my guess is there is still air in the master system


Sent from a device which doesn't always agree with my thumbs...

[johno90]

Did you push back any of the pistons with the cap on the master cylinder? how exactly did you bleed the new master cylinder? are you losing any fluid or does it just go soft? answer these and it will help a lot to work out whats going on.

[nissannewby]

Agree with above is it losing any fluid? If its not there could still be air in the system. Check your rubber lines one of them may have given up and is expanding under pressure giviing you a soft pedal and no braking force a thourough inspection for leaks will help check all your steel lines as best you can.

[johno90]

i have noticed that if you don't bench bleed gq masters they are a really prick to get all the air out of, also just throwing it out there all the callipers are bolted on tight cause a loose calliper will flex and give soft feel.

[Bogmeister]

Loose wheel bearings will allow flex too.

[Bigrig]

Hey mate

When you get the chance, slip back into the introductions section and post up some info on yourself and the rig. Something we request of all new members as a courtesy. No harm done and hopefully some of the responses here are leading you down the right path.

Other than that, welcome aboard!!

[patrolmuddar]

no fluid is getting lost and i spent hours bleeding the system when first put new master cylinder on

[patrolmuddar]

yeah no leaks as i am not losing fluid when i bleed brakes up they work fine then they just start to disappear until nothing left ... very frustrating:(

[johno90]

check to calipers sticking or wheel bearings getting hot, may be possible your getting brake fade from over heated fluid, are you using dot 3 and above? also how are you bleeding it?

[Morton]

it is back to normal in the morning? will strongly indicate overheating issues somewhere

[patrolmuddar]

nah the pedal only comes back when i bleed brakes i was also thinking overheating but pedal is gone even when cold once it goes

[patrolmuddar]

pump pedal till hard and open bleeder and close. works well then after a couple of trips to work usually about 200 kms on the way home on second trip they are pretty much gone quite scary on ipswich motorway

[kiwijase]

yeah but did you bench bleed the master?
It may be losing fluid back into its-self,it does happen.
other than that as mentioned,bad line expanding somewhere

[patrolmuddar]

to the point where the pedal is like a clutch pedal?

[Morton]

get it to a good brake shop ASAP, let them bleed the entire system for you, they will check everything