Brake problem

[basketcase]

I have a brake problem. I think I may have done the booster in. But I need confirmation.

Every so often my pedal goes straight to the floor, mainly after I have not used for a bit, like drive on highway. If I pump it once it will go to the floor then comes back and the brakes will work next time I pump it.

I think when I put the caliper back on after doing the hub seal yesterday I did not pump then brake before I started again and when I went to stop out of the drive way I braked and may have broken the booster then??

Am I right or is there something else??

[leroy]

If you can pump up the brakes try bleeding first then if prob still persists I would look at the master cylinder. Pretty unusual for a booster to go.

Leroy

[basketcase]

I have been told after stuffing around with brakes never put the brake pedal to the floor because you could stuff the seal in the booster. I was told to pump it about half way till its tight.

[Toos]

You can actually stuff the seals in the master cylinder. If you dont pump up the brakes slowly after changing the pads the cups in the master cylinder can invert. No brakes.

[Daisy]

Flush system and power bleed it???

Or at least take it to a brake shop??

[basketcase]

I am a tool. It is the master cylinder not the booster.

[Buggarr]

To save u time and effort replace ur Brake Master Cylinder, I stuffed around with a seal kit but to no avail i had to have it replaced $220.00 Place in Cranbourne, did it on the spot took about an hour & a half and the BGGR mobile was stopping and the peddal wasn't dropping to the floor anymore.

[basketcase]

I am still having problems.

I replaced the master cylinder and pressure bled the brakes. Did everything right I am sure. Pump the cylinder with fluid before putting it in, didn't press the pedal to the floor straight away, pumped a bit and then pressure bled it.

Every so often the pedal still goes all the way to the floor. Not as bad as before but still bad enough to get me in trouble if something jumps out in front of me and I haven't pumped the brake to be prepared.

I have checked for leaks and the only place I suspect is the gasket for the master cylinder. I think I farked it when I put it on. But that would really make a difference would it??

Any one got any idea's??

[zooki]

If the pedal drops without the car moving its a hydraulic problem- either seals or air, if it only does it if the car has moved in between braking then its your front wheel bearings are loose, the rotor moving around pushes the pistons in the calliper back and you have to pump the pedal to get the pads back in contact with the rotor.

[basketcase]

If the pedal drops without the car moving its a hydraulic problem- either seals or air, if it only does it if the car has moved in between braking then its your front wheel bearings are loose, the rotor moving around pushes the pistons in the calliper back and you have to pump the pedal to get the pads back in contact with the rotor.

Thanks you for that. That makes sense. Its only been happening since I did the bearings and the cv. I didn't need to buy a bloody new master cylinder!!!! Oh well spare for next time.

I'll get a hold of a 55mm socket and fix it. I am afraid of doing the nuts up to tight because I have farked some before from doing them up to tight.

[suicide jockey]

I have a brake problem. I think I may have done the booster in. But I need confirmation.

Every so often my pedal goes straight to the floor, mainly after I have not used for a bit, like drive on highway. If I pump it once it will go to the floor then comes back and the brakes will work next time I pump it.

I think when I put the caliper back on after doing the hub seal yesterday I did not pump then brake before I started again and when I went to stop out of the drive way I braked and may have broken the booster then??

Am I right or is there something else??

No it's your front caliper seal's pulling back, so get some new seals as they will be stuffed! And reasemble with rubber grease this time NOT brake fluid!
Problem generally occurs after pad replacemnt as piston travels too far back thus stretching seals! Polish pistons up really good with 600 - 800 wet & dry paper before assembling then bleed in normal way and problem should be no existant from now on!
Hope this helps Ya out a bit!
Cheers
Suicide Jockey

[basketcase]

Ok I think it is fixed now. I must have forgot to lock the tab over the front cv nut when I did the hub seal the other week. The front nut was stripped and fell off when I took the hub off. 83lux and I had to go hunt one down tonight so I could get to work in the morning. On the weekend I might take then other side off and have a look from when I did the cv.