23 replies to this topic

[PaulColeman]

My Daughter's 1976 Mini 1000 failed the MOT on its drum brakes not being up to scratch and the handbrake was unbalanced between the rear wheels. I checked the handbrake quadrants and they're free and the handbrake mechanisms both seemed to work. However, I did find that one of the back plates was loose so I'm hoping that's cured the handbrake issue?

 

I also found a couple of the wheel cylinders had seized and I've now replaced them both. The shoes have plenty of life in them and I cleaned all the dust out before giving the shoes and drums a rub over with 120grit wet and dry. I reassembled it all, bled the brakes and readjusted them all. I took it out for a test drive and the pedal was going down to the floor. So I re-bled them all and readjusted them again and now they're better but it pulls to the right when I brake sharply. To be honest an emergency stop would be very difficult in that car!!

 

The master cylinder is less than 2 years old and if anybody has any suggestions about what else I can try I'd like to hear them.

 

Thanks, Paul.

[David128]

HI I would suspect air still in system. Did you use an easy bleed or other method? Bleed the furthest brake from MC the progressively work closer use a Jam jar and clear tube so you can no longer see bubbles in the tube. Keep an eye on fluid levels so you dont pump air into MC

[PaulColeman]

Yes I used an easy bleed and followed the bleeding procedure in the Haynes manual (passenger front, driver front, passenger rear, driver rear for a RHD car). And I couldn't see any air in the clear pipe coming out.

[David128]

does the peddle firm up if pumped a few times if yes you have air. if not. get the car jacked up at front get assistant to operate foot brake lightly and check rotational effort at each front wheel. try to adjust until equal . If cant be achieved check shoes and springs correctly fitted. then readjust ..If I was near i'd come help.

[PaulColeman]

Thanks for the reply/tips.

 

I need to take it out for another test and double check the multiple pumps but I think it does firm up after multiple pushes? I will try readjusting the fronts just in case they're not balanced very well. Losing the will with this car!! First job when she has a job is a disc conversion.

[slidehammer]

Have you double checked that any joints disturbed by the changing of the wheel cylinders are leak free?, Also might be worth double checking the new wheel cylinders aren't leaking in the drum, as some of the pattern parts these days are poor. Also as above give it another bleed, I know it sounds silly but you are using brand new fluid and not stuff that has already been used or you have had sitting around that could have picked up moisture.?

[PaulColeman]

I have been using new fluid that I've had for a while but it's been kept with the lid on. I will just try bleeding again and put enough fluid through to replace everything in there already and then readjust.

 

The backs of the cylinders are not leaking at the joints.

Edited by PaulColeman, 02 April 2016 - 09:56 AM.

[ukcooper]

Old wise tale? Hand brake off?

[Stu.]

Sounds like air to me assuming you've adjusted them after bedding in from a test drive. Bedding the new shoes in takes a while though. I normally do a few short trips with plenty of hard breaking to get them cut in. (I do this on quiet roads with no traffic).

 

You dont need much adjustment on the cylinders to get a bit improvement on the handbrake either.

 

Id just make sure you've got all the air out, test drive, adjust cylinders, check handbrake and repeat until they are correct. Thats what I do and it works for my Minis and Austin A30.

 

Hope you get sorted

[ChopperHarris]

First thing to do is establish if it is pumping up and therefore air in the system.
Pump the pedal 5 times quickly and test if the pedal comes up higher...if so there is air and no amount of adjusting will help.
If its pulling that hard to the right the air must be in the left. Put some rag around the flexi pipe on each wheel in turn and clamp the hose with mole grips. Test the pedal, when it improved you have found the corner that has air or mal adjusted brakes. Check the adjustment and or bleed that corner.

Start at the front left.

There will be a slight improvement each time because you are restricting the circuit, but you are looking for a marked change.

[MRA]

brake fluid is hygroscopic.....  but I should think your fluid is ok, and that it just needs more bleeding.

[MRA]

First thing to do is establish if it is pumping up and therefore air in the system.
Pump the pedal 5 times quickly and test if the pedal comes up higher...if so there is air and no amount of adjusting will help.
If its pulling that hard to the right the air must be in the left. Put some rag around the flexi pipe on each wheel in turn and clamp the hose with mole grips. Test the pedal, when it improved you have found the corner that has air or mal adjusted brakes. Check the adjustment and or bleed that corner.

Start at the front left.

There will be a slight improvement each time because you are restricting the circuit, but you are looking for a marked change.

 

From a safety point of view clamping the hose with vice grips, moles etc is a big no no !  as they can easily damage the inside of the hose :-(   there are cheap hose clamps that do a much better safer job.

[carbon]

Paul,

 

With the twin leading shoe front brakes you have to nip both adjusters up on each side so there is fair bit of resistance to wheel turning, not easy to get this balanced. But if they are not adjusted up tight you get a lot of brake pedal movement.

 

Also when the front 'snail' adjusters get old they have tendency to slacken off, would be worth checking this as well.

[midridge2]

David128 said to bleed them furthest away from the M/C first and you have said you bleed them nearest the M/C  first, possible reason why you might have air in the system.   One of you must be wrong.

[cheesebadger]

I should be playing rugby in Milton Keynes tomorrow. Depending on where you are in/near Bedford, I could drop in on my way home to lend a hand (if still needed!)

 

Let me know...