What is life like with your car? Let us know and win £500 in John Lewis vouchers | No thanks
1991 Cavalier rearbrakes failed mot - spunkmyer
Hi...

My white Cavalier failed its MOT on the rear N/S rear brake

So I replaced the cylinder

Then with my wife I bleed the new cylinder by means of opening the vavle after she had started pushing the foot brake and closing the valve before her foot stopped moving.

I did this until I was 100% sure no air remaind or was trapped in the system then i topped up the brake fluid again to the max line.

The problem is all was well until I was driving down to my sister-in-laws house at 70mph and I started to get a slight vibrating down the steering wheel when ever I braked sometimes it would be a lot of shaking throught the steering wheel and other times you can just about feel the shake but only when you braked.

Then I got the same shaking down the steering wheel like when your front brake is warped but this time I was not braking just driving at 50mph and I was coming up to a round about so I went to slow down and there was no brake there whatever just a soft peddle and the brakes where just there I stopped the through using the gears and hand brake.

Strage after about ten minutes the brakes peddle seemed to be working again but now the brakes work but not well.

The car slows down with the peddle on the floor.

The brake fluid level is still on the max position and there are no brake fluid leaks

Any help would be great regards Mike

1991 Cavalier rearbrakes failed mot - Aprilia
There are a few possibilities - not least a problem with the master cylinder seals.

To be honest, I think the best idea is for you to stop driving this car and get it looked at professionally.
1991 Cavalier rearbrakes failed mot - Victorbox
Sounds to me like you've intentionally or perhaps unintentionally adjusted up the rear brake shoes (you can click up the so called automatic brake adjustment) so they are now too tight and are rubbing sufficiently to cause the vibration and boil the brake fluid through friction. Hence peddle goes to floor and now feels spongy as you have air in the system. After brakes have cooled some braking returns. The rear wheel that is binding will get pretty hot to touch.
1991 Cavalier rearbrakes failed mot - greaser pv
Agree with Victorbox , or , you may have been sold an incorrect sized cylinder , if in doubt you may have to pair up the rears so they are the same as the other side . I assume you bled the cylinder with the drum on ?
1991 Cavalier rearbrakes failed mot - spunkmyer
Hi..

Thanks for all you help and advice..

The car has passed its re-test

It appears the problem is to do with the rear brake with the new cylinder on it. I checked it yesterday after a short trip and the rear wheel was very hot.

So I must have adjusted the brake or it has over adjusted itself.

So how do you stop the auto adjusters form over adjusting?

Mike

1991 Cavalier rearbrakes failed mot - Civic8
Did you check the other side ie take drum off and have a look.you should replace cylinders as a pair as its not unusual if one side gone the other isnt far off.?Apart from what has been said.I agree with Aprilia take it to someone that knows
1991 Cavalier rearbrakes failed mot - Dalglish
spunkmyer:

the car must have passed its retest mot for you to legally use it on the road again?

assuming it has, aprillia gave the best advice. take it to a qualified mechanic. actually, get it towed or get a mobile mechanic to come to you.

don't drive the car.

your life and that of other motorists is not worth the risk to diy brake jobs.
1991 Cavalier rearbrakes failed mot - spunkmyer
I have confirmed the problem to be with the back brake and is to do with the self adjusting system.

Any advice on setting these systems to there correct settings would be of help.

Mike
1991 Cavalier rearbrakes failed mot - Dynamic Dave

Once you've put all the brake gubbings back together in the hub, according to Haynes, "Adjust the brakes by operating the footbrake at least 15 times. A clicking noise will be heard at the drums as the auto adjusters operate. When the clicking stops, adjustment is complete."

Obviously do this with the handbrake off and adjust the handbrake afterwards if necessary.

Fine in theory, but I've had to do this a couple of times on a stubborn Astra with these auto adjusters.
1991 Cavalier rearbrakes failed mot - Mikey Jay
I agree with Aprilia.It might be better to have the car looked at professionally.The problem with bleeding brakes is that you can sometimes wear the master cylinder seals out due to the piston travelling too far and now it is sometimes recommended that the brake pedal is not depressed fully to the floor during the brake bleeding process,for this reason. Mikey
1991 Cavalier rearbrakes failed mot - Aprilia
I agree with Aprilia.It might be better to have the car
looked at professionally.The problem with bleeding brakes is that you can
sometimes wear the master cylinder seals out due to the piston
travelling too far and now it is sometimes recommended that
the brake pedal is not depressed fully to the floor during
the brake bleeding process,for this reason. Mikey


I never bleed brakes by 'pumping the pedal' for this very reason. Vauxhall m/c seem particularly prone to seal problems for some reason.
It is always better to bleed the brakes using a pressure bleeder (Easibleed, or similar) or (my preference) a MityVac vacuum bleeder. Its a nice relaxed one man job and no risk of damaging any seals.
1991 Cavalier rearbrakes failed mot - spunkmyer
Hi all...

Ok I found out the problem was the rear N/S self adjuster spring had lost its tension due to age I think.

So I have replaced the spring and cleaned all the old brake dust and any rust.

re-greased the bearings and set them.

flushed brake fluid with a pressure bleed system.

and all is working fine now.

Thanks for all your help.

Mike