Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[Ady]

Whilst doing 20 mph tried to stop the peddle sunk to the floor, second pump returned to normal and I stopped just in time. Since done about 5 miles (nervously) home and brakes performed fine.

On Monday I replaced rear discs, pads and hand brake shoes, cleaned up very rust calipers.
I know that this was all done correct as have done many before, I followed omf maintence guide and my dad who is a mech supervised. I have done 20 miles since changing and before incident.

My brake fluid is a little high and I suspect that could be the problem do will take done out in a bit,

Does anyone have any other theory's

Thanks

Ady

[omegod]

Did you disconnect the pipes and not bleed them properly? could you have possibly flipped the master cylinder seals when pushing the pistons back in, often heard of it but took it as an urban myth as i've never come across it actually happening

[Ady]

Hi omega baron

I didn't disconnect the brake pipes, I cleaned calipers on the car. I did apply brakes without the pads in to check pistons were moving ok and then pushed them back into place.
Never heard of flipping cylinder, is there an easy fix to that?

My calipers where very rusty and the inside pads were rusted in place so rear bakes have scarely never worked properly since I've owned the car.

[chrisgixer]

Was it to the floor? Fully to the floor, with no braking response at all, or just a lack of servo assistance that felt like no brakes?

Did the car stall or drop revs at all?



Was this first touch of the pedal after a lay up?

[Ady]

It was fully to the floor pumped it once and it went straight back to normal.

I fitted brakes Monday night, drive home 5 miles then work in the morning another 5 miles then got almost home this happened. Since done another 5 miles with no problem.

[Ady]

No stalling or rev loss that I noticed but I was paying more attention to the bumper of the car in front lol

[alank46]

Sounds to me as though a piece of dirt got stuck temporarlly under a valve or a seal and that the second pump of the pedal shifted it.  In which case it may never happen again or it may happen the next time you use the brakes.  It would be worth doing a very comprehensive flush of the brake system, push at least 1 litre of brake fluid through it, and preferably refurbish the master cylinder first, or fit a new one.
Alan

[Ady]

Thanks for the advice everyone.

Where can I get a new master cylinder from? Tried euro car parts and GFS but neither stock it on there web sites.

Also is it a job I should get booked in a garage to do or can I do it on the drive? Can do most stuff but never attempted a cylinder.

[05omegav6]

Two nuts and a few pipe unions... iirc. Messy but perfectly feasible 

[chrisgixer]

Not too bad to change master cylinder.

I presume an autopsy will follow? I'd want to know I'd found the fault personally.

[Keith ABS]

  I have seen a new master cylinder on ebay this morning
Keith B

[al brown]

Check your brake pads is my advice. I only say this as when I bought the wife's car, the guy I bought it from had not long changed the front pads. We had it a week when the same thing happened. I was driving and when I pressed the brake nothing happened, pedal straight to the floor. Second, panicked, press had them working fine. I got home and went to find the cause only to find one of the front pads had gone. Pad material had separated and vacated the car.
Many little things can be ignored on a car if it is an occasional fault, but not with brakes. Personally I would find the fault if possible rather than just guess and change bits.
At very least give a good check of the whole brake system, just because it was the rears you were just working on doesn't mean the problem won't be somewhere else.

[flyer 0712]

On my last omega i was going to have all 4 flexy hoses changed as front needed doing so thought while he was at it he may as well do the rears,,,however he advised me that because the master cyl would have  of the same age that by changing all four at once and brake fluid that the extra pressure in the master cyl could just turn the seals over as he had this happen before to him ?? so just done the two and all was ok.......I have heard it said that it can happen but i believe it was on the vectra....

[alank46]

What turns the seals over is pushing the caliper pistons back without opening the bleed valve first.  Changing the hoses will have no effect whatsoever on pressure in the master cyl!!!!!!

[Magwheels]

. I was driving and when I pressed the brake nothing happened, pedal straight to the floor. Second, panicked, press had them working fine. I got home and went to find the cause only to find one of the front pads had gone. Pad material had separated and vacated the car.
 

I had the very same thing happen on the wife's Golf, luckily it was me driving and I was going slow....foot to the floor and lights flashing on the dash, I grabbed the handbrake and pumped the pedal and suddenly all was normal. Drove a bit further (as I was on dual carriageway) and on next application heard the sound of metal on metal. Drove home cautiously and when I looked at the pad ALL the friction material had gone from one side.

Looking on the internet it seems it is not that uncommon an occurrence nowadays!!

Nice!!!