ABS on rear Drum Brakes?

[spaceface]

Brake pedal has just sunk while braking and there's fluid leaking below the rear drum. I haven't looked properly but I'm assuming the rear wheel brake cylinder has failed. Checking prices for cylinders and shoes I noticed they were available for vehicles either with or without ABS. This has confused me as after looking under the car once when it was on a ramp and asking about ABS on the rear I was advised it was only on the front wheels. If so do I need parts for a car with or without ABS?

I recently has a problem with the car binging and nearly stalling. As I was only a mile from home when the brakes leaked I chanced driving it and while driving there were occasional bings but no dashboard lights. The fluid level is a bit low but I suspect I've only lost a small amount of fluid and there was no low fluid level light lit. I'm wondering if the previous bings were due to this fault starting. Would the car know there was a problem possibly through low fluid fluid pressure and the bings be warning me of that?

[PaulC5]

Whoever said abs is only on the front wheels does not know what they are talking about. A car either has abs or does not have abs and it works on all wheels. To get the correct rear cylinder you are best to use your VIN in the parts diagrams. As well as a cylinder you will likely need new brake shoes since these may be soaked in fluid. I have not worked on a 206 but on the Citroens with rear drums the hub nut has to be replaced each time as well as the cap over it.

[spaceface]

Thanks. I've just had a better look underneath and there's an electrical connector on the back plate. Presumably this is for a sensor. I'm in two minds about doing the work. The cylinder nuts and brake pipe nut look very old and rusted. I remember doing these on early Minis and the brake pipes would break when twisted. My mechanic is only 1/2 mile away, I'll ask how much he'll charge and the likelihood of him making up a brake hose if mine breaks.

Well miffed about this. Loads of running around to do plus two holidays planned. Just grateful it happened close to home. Currently looking for breakdown cover after letting mine lapse after 25+ years and a price penalty for older cars.

[PaulC5]

I have replaced a few rear cylinders on our Citroens, C3 and Cactus and not had a brake pipe twist. It might help to spray wd40 on the nut in advance to help but make sure you use a brake pipe spanner so the nut does not get rounded off. The hub nuts if like our Citroens are a high torque and are peened over, hence why they are a one use nut. Get new nuts before doing the job so you can get the right size socket - impact ones are cheapest. Once the drum is off take a photo of the shoes, springs, adjuster so you know how they go back. If the nut cap is like the Citroen ones do not hammer it back on in the middle or it will flatten it against the nut and need replacing again, best to use an old bearing shell the same diameter as the cover outside and hit that.

[spaceface]

You've reminded me about doing one of these probably on a ZX. Brake pipe nut had rounded off, my dad had turned up and he had a small pipe wrench in his car which worked brilliantly on the rounded nut.

[GiveMeABreak]

... and I'd advise you not to take your car back to whoever told you ABS is only on the front!

[spaceface]

Removed the hub and found the problem. The cylinder was about 6mm away from the backplate at one end so the end of the piston was missing the end of the shoe. Presumably the piston is stepped under the rubber cover and this was operating the brake. Big build up of white stuff that old brake fluid can leave behind. This has been misaligned for years and must have been leaking slightly for years. I suspect whoever fitted the pads turned the one on that side 90 degrees to fit it at the bottom without realising it was behind the piston at the top and pulled the cylinder forward.

[GiveMeABreak]

Well spotted and thanks for posting the pics and update - sure to be helpful to others.

[RichardW]

I had similar trouble on a ZX... which ever donkey had fitted the rear brakes had made a right arse of it! First off the thread was mashed on the stub axle (how??), then when I got it off, they had got it together all wrong, which had allowed one of the shoes to turn a bit, which had worn a groove in the drum, and ultimately, as yours, allowed the piston to pop out. Removing the cylinder resulted in breaking the pipe off... AND they'd lost half the bits of the handbrake adjuster! So I ended up with new pipe, cylinder, drums, bearings, shoes and hardware. Finding someone to make up a pipe at the weekend, and press in the new bearings was a bit of a challenge. Fortunately I managed to recover the thread on the axle enough to get the nut to torque up, as that would have been another whole world of pain!

You might be able to get the cylinder off by slackening the pipe a touch, undoing the bolts holding it, and then pulling it through the back plate to allow you unscrew it off the pipe, rather than having to turn the (no doubt seized) pipe nut.

[spaceface]

On my first ZX the brake pedal would bite(?) at different heights although there was no fluid loss or sinking. Took the drum off to find the friction material of one shoe was completely detached and moving around inside the drum. Not sure how possible it is but was very relieved it hadn't got wedged between the drum and other shoe.

I removed the bolt holding the cylinder to attempt to clean the white crud from behind it to try and fit it properly and considered continuing to use it which I accept isn't wise but there wasn't much play in the pipe so was concerned about damaging it although I will check to see how possible that is. After wire brushing the pipe and connector look surprisingly uncorroded. I've WD40'd it which will have a few days to soak so hopefully it'll release without trauma and swearing.

I bought the car from a friend less than 2 years ago who bought it at 3 years old and low mileage. The majority if not all of work has been done by two professional mechanics. One for the early ownership and another for more recent work. I'm going to check the service history for mention of rear brake work.

[PaulC5]

Some thoughts but not necessarily in the right order.

The adjuster is very similar to the ones on the Cactus and C3. When you remove it to clean it all up, then put a bit of copper grease on its threads so it works better. Put it back at min length so it is easier to fit the shoes back and then turn its wheel to about where it was before, try fitting the drum, push the pedal/use handbrake, spin the drum, then remove the drum, turn the adjuster more, etc with the aim of adjusting it so the drum just rubs.

Tie some wire round the cylinder pistons so they do not pop out. I use a Mityvac brake bleeder pump to suck brake fluid out so I have bled cylinders first just after putting them back so I could squeeze the pistons together to get as much of the air out bearing in mind the cylinders are not horizontal with the car jacked up and if pedal pumping it only pushes the pistons out so not as much air will be removed. I have been able to swap the old and new cylinders quickly after undoing the brake pipe to minimise the loss of fluid and with the bleed screw slack so gravity pushes some initial air out.

With the handbrake correctly adjusted the lever on the rear shoe should be fully back against the shoe plate. If it is not fully back the adjuster will not automatically work as the pedal is pressed/released. When you fit the shoes back, I find it best to fit the handbrake cable to the rear shoe, then this shoe to the back plate, then the adjuster to the front shoe and fit the upper and lower springs to both shoes and then the front shoe to the back plate and then the adjuster spring. Removing the shoes is the reverse of this - front shoe first then rear. Once the shoes are in place remove the wire holding the pistons in place.

Do not peen over the hub nut until you are happy with the adjustment and everything works. For this 2 hammers work well with a ball pein end doing the peening and another hammer hitting that hammer. If you do not know the correct torque ask on here since it can be various amounts depending on the drum diameter and nut type.

[spaceface]

AAAAAAAAARRRRRRRRRRRGGGGGGGHHHHHHH!!!!!!!!!!! Swapped the leaking cylinder, cleaned out all the crap, bled, adjusted. Job done. Turned the car around to swap just the shoes on the other side thinking "this'll be quick, no cylinder to change" fitting the last pad that stupid washer twanged away and cannot be found. Hour and a half searching and still not found.
I partly copied a youtube video to fit these. Put the pin through and hold it from the rear, hold the washer in pliers and push and turn onto the pin. Sounds far more straightforward than it is. I tried mole grips which were too wide and slightly bent the washer. Narrow mole grips might be easier but I don't have any. Is there an easier way of fitting these?

[RichardW]

There is a proper tool for doing these. I used to use a pair of long nosed pliers, but they are a total pain in the posterior!!

[PaulC5]

I use a brake spring washer tool, makes the job of removing and fitting those washers a lot easier with one hand holding the pin in at the back of the back plate and the tool pushing the clip back on and twisting so the pin aligns/locks in place. An example tool https://www.ebay.co.uk/itm/175064637950 ... gLQovD_BwE

[spaceface]

Managed to find the clip washer by fitting two magnetic knife holders to a pole sander and going over the grass in sections. It had flown almost 20 feet behind me! I had tried to buy one but they seemed only available in expensive kits with very few in stock anywhere. However, GAMECHANGER!!! I made a tool using a 5/8 socket with a rubber tap washer in it fitted to a screwdriver socket holder. It was unbelievably easy to fit these clips using that. I also used a large spring clamp to hold the shoe in place which was much easier. I fitted the front shoe to the back plate, handbrake cable onto the rear shoe, adjuster between them (notch for the adjuster lock facing outwards) then second shoe onto the backplate. Top spring in at 90 degrees then a hooked tool for the other end. Hooked tool for the bottom spring and finally the adjuster lock. Fiddly doing the springs but much easier than fitting them at the same time as the shoes. Fitting the shoes with springs is like putting a cat into a box. You might win but it won't be easy.

Bit of play in the pedal which I suspect is air in the system. I bled it with a basic one way valve on a short pipe which works however fluid was leaking from around the bleed nipple thread. I suspect the pressure is a bit high against the one way valve.
I also noticed I can hear the servo hissing when pressing the pedal which I'm sure I couldn't before.