ZX drum brakes binding (Failed MOT) UPDATE ***

citroenbx · Post by **citroenbx** » 11 Jul 2006, 07:23

I'm Looking for some Help
Its that time of year and the local MOT station has just failed my
1994 1.9TD ZX saying its back brakes are binding.

I recently adjusted teh handbrake because of high travel on the lever.

I did notice after adjustment (working from advice from the Haynes BOL) that the lever was just lifting off the carpet and the back brakes were biting after a few clicks.

Now Haynes says the brakes should be on after 3 clicks of the rachet but this is just as it lifts off the carpet ?

Is this my problem ? In Millimeters how far should the lever liff from the carpet (Or is this a crude incorrect way of measuring )

Anyhow i live to you people who know....Thanks

LeeDJC · Post by **LeeDJC** » 11 Jul 2006, 07:25

I didn't think it was the distance of travel that was important, but the number of clicks as the BOL says.

citroenbx · Post by **citroenbx** » 11 Jul 2006, 07:41

Yes that makes sense ....because everyones cable stretch is different.

When i adjusted the handbrake i did spin the wheels to check they were realesing and they were fine a few weeks ago..........Wonder whats gone wrong on test day ?
cheers anyhow

Post by **RichardW** » 11 Jul 2006, 07:53

ZX drum brakes are not exactly known for the quality of their adjusters. You probably need to strip the brakes down and clean and lube the adjusters - you've probably overtightened the cables to compensate for a non-working adjuster. You'll proabably find the cylinders are leaking while you're in there, and removing them will break the pipes

Hopefully you'll get away without replacing the drums (and therefore bearings) as I had to.

To annoy you, I've just fitted new rear pads to our ZX with discs on the back. Took about 20 mintues / side 8) And the brakes work much better than the drum set up on the previous car ever did

citroenbx · Post by **citroenbx** » 11 Jul 2006, 08:18

You should see the tears in my eyes now............

I had the drums off to check the shoes before i adjusted the hand brake.

The shoes where perfect the cylinders were clean and dry and the adjusters were clean but very dry (is this normal) i didn't want to start squirting the oily stuff in there.

As a side thought the car free wheels perfectly with handbrake off even on nearly flat surfaces withthe handbrake off.

Anyhow thought id get some advice early. Off to collect the car today and get stripping at least the sun is shining.

Yes your right about the rear disk systems with ABS but my cars a few years before they arrived mine a pre facelift model....
Cheers

Post by **RichardW** » 11 Jul 2006, 08:38

Ours is 94M. God knows how it ended up with discs and ABS, but it did - maybe a demonstrator? No airbag, but the sensor is there beside the handbrake, and there appears to be seat belt pre-tensioners. Right hotch potch!

Hmm, sounds like the brakes are in order, perhaps the tester just assumed they were dragging, as there were few clicks on the handbrake? Any chance you can ask him before you go ripping the drums off?

citroenbx · Post by **citroenbx** » 11 Jul 2006, 08:43

Yes i will do.........My Other ZX is a 95 TD Advantage on an M plate this has ABS and disks all round.So looks like my Aura just missed out...

mezuk04 · Post by **mezuk04** » 11 Jul 2006, 09:00

My ZX suffered from continued high handbrake travel, about 10 clicks, maybe more.

We continued doing the tightening procedure (handbrake and brake stomping) which would halve the clicks quite nicely, after a while it increased more and more.

We decided to inspect the drums to find one adjuster (passenger side) had kind of disintegrated and the other side, the cyclinder was leaking, we also changed both cables.

jeremy · Post by **jeremy** » 11 Jul 2006, 16:50

The ZX drum brake adjusters are really rather a nasty set up when they get old. I recently renewed the adjuster on ours but in fact there is no reason why i could not have overhauled them and expected them to work.

What you will have to do is to take them apart and carefully clean them in solvent and remove all the crud and grease. you then need to examine all the teeth - both on the wheel and the spring-loaded plate that engages the wheel and remove any burrs. Don't get carried away with the file but a burr can stop it working.

Having got all the adjuster components nice and clean you can re-assemble - taking care to GREASE the thread and to wind the wheel over the grease to get some under it. Re-assemble and make sure that strange right-angled bit of metal rocks and moves the toothed wheel away from the adjuster body when the wheel is free. This is essential to ensure the thing does actually adjust and your problem is probably that the old grease is stopping the threaded bit moving in and out properly.

having done that - re-asemble and before you lock the new nut make sure you can hear the adjuster clicking. (You should slacken the cables again.) If you can't hear the adjuster click with the footbrake - take the drum off again and find out what is wrong.

Adjust up on the footbrake then tension the cables. DO NOT OVERTENSION. If the back brake binds it overheats. I had one overheat on my Renault 21 (essentially the same system) and it boiled the fluid in the cylinder - and I suddenly found I had only one of the diagonal split circuits working. So a run with overtight cables could boil both cylinders - resulting in total failure.

This is for the Bendix system.

Dave Burns · Post by **Dave Burns** » 11 Jul 2006, 23:54

When you spun the wheel the car was raised off the ground, meaning suspension arm and cable in a different orientation to car sat on its wheels, cables may have gone taught when suspension arms in normal orientation.

Adjusting handbrake....never do this at the cable end....can only be succesfully achieved by adjusting the shoes themselves so they just clear the drum, do it with the cable and you end up with the problem you have got, plus there is a loss of leverage and mechanical advantage, end result is you still have a crap parking brake that wont get you the ticket.

Only use cable adjusters to take the slack out of the cable, they must not be pulling on the shoes when the brake is off, this is one of the reason for auto adjusters not working.

Dave

citroenbx · Post by **citroenbx** » 12 Jul 2006, 10:14

Well got the car home yesterday from MOT Station....Looked at the handbrake cables they were all Kinked and Rusty where the plastic protection had worn.

The handbrake works fine but doesn't always release the wheel maybe its snagging inside the sheath.

Going to change them and see how it goes....I took the drums off a few weeks ago just to check the shoes and the adjusters looked fine the shoes had even wear and were in good condition.

Thanks so far i'll keep you posted

jgra1 · Post by **jgra1** » 12 Jul 2006, 10:34

yep sounds like cables.. quite a common cause of dragging..

John..

jeremy · Post by **jeremy** » 12 Jul 2006, 14:18

cables are well known for failing - about £12 each from GSF or Euro Car Parts if I recall.

citroenbx · Post by **citroenbx** » 15 Jul 2006, 10:24

Thanks everyones advice my car has passed its MOT now..It was the handbrake cables causing the nearside wheel to bind..Replaced the cables with new and all was fine...Roll on 2007