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In all respects the brakes are working perfectly but just recently when coming to a absolute stop they have grabbed/juddered just before stopping. This is only from say one mph to stop. Any previous experience.
ken
 

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In all respects the brakes are working perfectly but just recently when coming to a absolute stop they have grabbed/juddered just before stopping. This is only from say one mph to stop. Any previous experience.
ken
Well there is timing! o_O Yep, mine is doing this for a while now, and alarmingly so.

It has done it very occasionally since I've had it but it has got worse recently. The front right disc is occasionally binding sometimes when stopped, and then causing the car not to creep when I lift the brake and then break free when I accelerate... I actually had one occasion last week where I stopped at the lights and couldn't move again even with my foot right down!

The Ion has very limited torque from stationary (it won't climb a curb without momentum) so I couldn't get it to break free and get moving, I had to reverse slightly at a green light then go forwards. Very embarrassing with another car right behind me, and in the dark!:oops:

I've already done a bit of work on the front brakes a while ago as they are vibrating under braking as well as causing a little bit of vibration at speed when not braking and also dragging slightly - and I found a couple of things. One is that there is a rubber sleeve/bush on the lower guide pin, item 8 in the following diagram, with item D being the rubber sleeve that sits over it:

Ion Brakes.png


On my right front caliper this rubber sleeve is soft and swollen and is trying to ride up over the shoulder on the pin that it is supposed to sit in instead of staying in place, in fact I had difficulty refitting the pin because of this as it kept trying to slide out of the recess. There is evidence of normal mineral grease having been applied to the guide pin so its possible this has caused the rubber to swell and go soft, or perhaps it has just gone bad with age and heat. (Possible design flaw - I don't understand why the lower guide pin has a rubber bush over the pin - I've never seen that on other cars...)

Here are the two versions of the pin, with the bottom one being the one with the rubber bush:

IMG_0317.JPG
IMG_0314.JPG

So this may be causing the caliper not to retract properly and thus cause the brake to be "too" sensitive or even stick on slightly, and might explain the reputation these cars have for "sticking" or "binding" front brakes...

I also found both the pins with the rubber bush had been fitted on the right hand side of the car and the metal ones both on the left, instead of the metal pin being the top at both sides and rubber at the bottom on both sides - so someone has been in here before I bought the car and mixed them up!

The other thing I found with mine is the discs and pads are in a bad state even at 36k - with the inner pad seemingly having a narrower pad surface than the outer pad, with the outer pad overhanging the rust lip on the disc by over 5mm, almost as if the car originally had narrow pads fitted while the disc wore down and then someone changed one of them to a wider (perhaps correct pad) !? Doesn't make sense to me at all. You can see the difference in swept area of the two pads from the same disc with the top one (from the inside of the car) being clearly narrower:

IMG_0318.JPG


And you can clearly see the wider pad overlapping right onto the rust lip which normally would only form beyond the left edge of the pad, in this picture:

IMG_0383.JPG


That pad rubbing directly on top of the rust lip causes a rough "scraping" noise when applying the brakes lightly and also causes vibration at speed because the rust lip is obviously irregular. It will also prevent this pad from biting down correctly onto the flat disc area where it is supposed to be working as the lip will hold it up.

I filed back the rust lip as much as possible and chamfered the pads a bit as a temporary measure which did improve things a lot for a few weeks but it is as bad as ever now and I've decided that the only real solution is to fit new discs and pads for the scraping/vibration problem as someone has really screwed around with these in the past, and I'm going to fit new guide pins for the binding/sticking issue and caliper rattle, with new rubber sleeves/bushes and make sure they're lubricated with silicone grease not mineral grease.

If you don't lubricate the guide pins the calipers will rattle over broken road surfaces on these, but you can't use a mineral grease like normal lithium grease without damaging the rubber sleeve/bush. Also there is an anti-rattle spring on the inner pad that needs to be tensioned, if this is not it may also cause pad rattle. (One of mine was squashed flat and had lost its tension)

A set of discs/pads for these on ebay is actually pretty decent at £52 all up including delivery, and although I have not fitted them yet I already have them in my possession, and they seem to be of good quality:

Front Apec Brake Disc (Pair) and Pads Set for PEUGEOT ION 0 ltr | eBay

I also note that the swept areas of these new pads are identical for each pair unlike the originals that seem to be mismatched somehow...

The guide pins are a dealer only part but are surprisingly reasonable at £5.56 each plus vat so about £26 all up for four, and I will be picking these up from Peugeot in the next few days.

I'll let you know how I get on with this, the only thing is as I'll be changing both the pins, and the discs/pads at the same time, if (when, I hope!) the problems are solved I won't be able to say for certainty which was the actual cause of the binding, but I'd put my money on the swollen rubber sleeves as the binding issue, and its certainly much cheaper/easier to correctly lubricate and replace the pins with the rubber sleeves first to see if that fixes it if the pads/discs are otherwise in good order.
 

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I changed my mind and instead of ordering the slide pins (with rubber bush D included) I ordered two of the "Brake Caliper Repair Kit" part 1606225380 at £10.30 each.

This kit also includes the swollen rubber bush 'D', and I decided to go this way as I really ought to replace the outer rubber boots for the pins which may have also been softened or damaged by mineral grease, and that it was unlikely that the pins themselves being worn (they don't look worn at all) were the cause of the caliper rattle I had before - more likely it was just a lack of the right grease. This kit comes with seals for the piston as well but I won't be touching those and will save them away in case they're ever needed in future.

I'll report back the results but it may be a few weeks before I get time to work on this given the poor weather and other factors. (I work outside on the driveway...)
 

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In all respects the brakes are working perfectly but just recently when coming to a absolute stop they have grabbed/juddered just before stopping. This is only from say one mph to stop. Any previous experience.
ken
@KenB

Just made a discovery on mine - although I definitely have problems with my front brakes that need sorting as well, I think I've narrowed down the source of the grabbing to the rear left drum brake...:confused:

The breakthrough was testing it with the handbrake, which on this car operates the rear drum brakes.

When I was leaving work yesterday I noticed it was acting very grabby again as I was rolling very slowly and trying to stop, on a hunch I tried applying the handbrake instead of the foot brake and got the exact same result - pulling fairly gently on the hand brake was causing a sudden lurching stop and it was obvious that the rear left brake was locking up. In fact if I rolled forward a bit and pulled it on a bit more it was actually abruptly locking the rear left wheel and skidding on wet road. That should not happen on a handbrake on drum brakes which are not usually very sensitive. I could also hear that left drum squealing a bit.

So as a test, next time yours is feeling grabby and over sensitive as you come to a stop, try pulling the handbrake on moderately while you're still moving instead of applying the foot brake, if that too seems to grab and lock suddenly on one side then your problem is most likely also in one of the rear drums, in which case you'd want to get someone to give your rear brakes a service or do it yourself if you're a DIY'er.

Weather permitting I'm going to pull the rear drums apart this weekend and give them a service.
 

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Discussion Starter #5
Simon, thanks for all that info.
At the moment mine seems to have cleared itself again but interesting you say about drum rears as on one occasion i had a feeling it was the rear N/S that locked up. Also i had wondered why the steering wheel did not lurch one way as i would expect with a sticking type front disc. I suspect that in normal EV type driving the rears get little use and it may be no more than a little rust needs clearing off. If it happens again i will remove drums to investigate and look forward to your findings.

Ken
 

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Hi Ken,

I just spent the day overhauling the rear drum brakes and that seems to have fixed the grabbing/locking up. :) The hand brake and foot brake both apply nice and smoothly when coming to a stop now, and the squeal that I was sometimes hearing has gone as well.

There wasn't anything major wrong - the drums and linings are both in good condition with the linings still 3.5mm thick. (brand new is 4mm, 1mm is the minimum allowed)

Not sure if you're a DIY'er or not but a short summary of what I did is:

* Disassemble everything, but leaving the hydraulic cylinder in place, no need to remove that. The drum has two threaded holes you screw a couple of bolts into to use as a puller to pull the drum off.
* Clean all the muck out of the hub assembly especially on the backing plate with spray brake cleaner.
* Lightly sand a slight rust lip off the inside edge of the drum that may have been touching the edge of the shoe linings.
* Wire brush the rust edge off the drum where it meets the backing plate.
* File a slight chamfer on each end of the shoe linings to help avoid them grabbing.
* Grease the raised shoe support "ears" on the backing plate with copper grease and grease the adjuster thread with normal lithium grease.
* Reassemble everything except drum.
* Adjust hand brake adjuster in each drum unit until the shoes are not quite touching the drum - I ended up with the hand brake starting to act with 3 clicks of the hand brake and on properly by about 5 or 6, and tweaked the adjustments to make sure both sides started gripping at the same number of teeth on the handbrake.

Here's a few pictures I took along the way...

IMG_0456.JPG

IMG_0459.JPG

IMG_0460.JPG


I think the main reason for them trying to grab was that the backing plate seems to have an enamel paint on it which has worn right through to bare metal where the shoes rest against it on some of the pads, like the one below:

IMG_0464.JPG


Before I disassembled it, when trying to slide the top of the shoes (cylinder end) side to side they were jamming and seizing - probably getting caught in these worn grooves in the enamel coating. I put plenty of copper grease on the raised supports:

IMG_0465.JPG


That, and giving everything a good clean seems to have done the trick - you can now slide the top end of the shoes side to side relatively easily without them sticking or grabbing which means when they apply they are able to centre easily which will help avoid the leading pad digging in.

I'm thinking about doing the front disc and pad replacement tomorrow but I took it for a 30 minute drive today to give the brakes plenty of testing first after only having done the rear brakes to try to confirm it was indeed the rear left that was grabbing and seizing, and I'm satisfied that's what it was.
 

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Discussion Starter #7
Thanks again. I understand what you say even though i would describe myself as a semi retired DIYer.

What was the adjustment like before you started ? Perhaps they had backed off a bit giving rise to the leading show digging in a bit ? Do they have auto adjusters ? What you did used to be part of a service but i dont suppose it is now.

Ken
 

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Yes ! I jad this first a couple of years ago and asked on here. ...no one else had the problem and I thought I was alone. You've made me happy. Our also.did the brakes staying on when pedal. Related but it was the rear brakes. The car would sit down as it tried to move away.

Ours had to have the front discs and pads changed as they'd seized from under use and the inner gave of both discs was like the surface of Mars. Utterly shot.

Since then it's been fine but recurs occasionally when wet. I thought it was a dodgy abs sensor getting wet as I gather this can cause similar symptoms, but I reckon it's now just wet or rusty brakes. I think the car thinks 'I'm not slowing as I should' and dumps the emergency brake assist. I find that when it occurs, it can be cured by getting up to speed, knocking the car into N to kill the regen brakes, amd give them a good hard press. You'll hear the usual grating noises as the cap is shifted amd the brakes get a work out.

I bet they'll. Work fine after that..

I think this is a real problem. With EVs. Standard car brakes might need a rethink with bigger clearances and better shielding to keep the components dry. Even fancy alloy wheels don't help.

A mate has an ampera and has had to get brakes replaced through lack of use gumming them up. Whilst we need it for range, it seems regen brakes might save brake wear but corrosion and stickiness cause us more problems
 

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Yes ! I jad this first a couple of years ago and asked on here. ...no one else had the problem and I thought I was alone. You've made me happy. Our also.did the brakes staying on when pedal. Related but it was the rear brakes. The car would sit down as it tried to move away.
Yes that's what mine was doing - locking the rear left wheel. Once I couldn't even get moving forwards with full throttle as the rear left had jammed on completely, I had to reverse (at a traffic light no less) to un-jam it! It's definitely the rear brakes doing this, contrary to what I initially thought.
Ours had to have the front discs and pads changed as they'd seized from under use and the inner gave of both discs was like the surface of Mars. Utterly shot.
My front discs and pads were shot as well - plenty of thickness left on both but the discs had serious rust lips and were slightly warped causing a bad vibration when braking at speed. The pads were also in poor condition.

More seriously though, the rubber bush on the bottom slide pin was swollen and soft - causing the caliper slide pin to jam. I ended up ordering the "brake caliper repair kit" from Peugeot which includes new seals including this rubber bush - and I changed the bush (and the rubber boots for the pins) and used some permatex silicone based grease on the pins to lubricate them both well but without damaging the rubber bush.

This completely eliminated the incessant rattle over rough roads that the calipers had before and the front brakes are very smooth and progressive feeling now - better than they have ever been.
Since then it's been fine but recurs occasionally when wet. I thought it was a dodgy abs sensor getting wet as I gather this can cause similar symptoms, but I reckon it's now just wet or rusty brakes. I think the car thinks 'I'm not slowing as I should' and dumps the emergency brake assist. I find that when it occurs, it can be cured by getting up to speed, knocking the car into N to kill the regen brakes, amd give them a good hard press. You'll hear the usual grating noises as the cap is shifted amd the brakes get a work out.

I bet they'll. Work fine after that..
It's nothing to do with ABS, emergency brake assist or anything like that, its purely a problem with the rear drum brake assembly. The same locking and jamming occurs pulling the handbrake lever - and ABS cannot modulate the handbrake application.

Pulling the hand brake on hard at speed for a couple of seconds does temporarily cure it as you say, but the cure lasts a short time and they are usually playing up again soon after.

Despite the strip down and clean/lube my rear brakes are still oversensitive and prone to jamming on, but only intermittently, and like yours seem to be more problematic when it is wet or very cold, I suspect this is because it changes the frictional characteristics of the shoe linings.

There's a very good article that describes how this happens here:

Engineering Inspiration - The Geometry of Drum Brakes

Grabbing is where it suddenly applies strongly enough to lock the wheel with a light touch of the brake and "spragging" is when it locks on completely even when you release the brake. (which happened to me a couple of times)

According to that article the main cause for this is shoes which are contacting at the ends instead of the middle when the brake is first applied, this causes excessive "shoe factor" on the leading shoe and leads to grabbing.

Another good article is this one:

Rear Brake Drag or Lockup - Drum Brakes - Phoenix Systems

This one points out several reasons for grabbing drum brakes including:

Shoe Lands or Bosses

The shoe lands or “bosses” are an often overlooked item when looking for the cause of a rear wheel lockup condition. The shoe lands keep the brake shoes square with the drum and provide a friction surface for the shoes to move against. Over time the bosses can become grooved and corroded as in Figure 61.6. This grooving can allow the brake shoe to hang on either the apply or release of the brakes which can cause lockup. The shoe lands should be checked during the inspection and if rear brake service is performed they should be cleaned and lubed.
As I reported earlier there are deep grooves worn into the "shoe lands" on the backplate through the paint layer, this is causing the shoe edge to snag on the grooves and this can also cause the leading shoe to stick on. In fact I sometimes hear a "click" from the rear brakes when I release the brake pedal - I think it's a good bet that the snagging shoe is jumping across the groove on the lands when this happens.

As I'm still seeing this problem intermittently the next thing I'm going to do is wire brush the shoe lands on the backplate back to flat, smooth bare metal then re-assemble it making sure to grease the lands properly, this should allow the shoes to slide smoothly and assuming this is the root cause, fix the problem.

If that doesn't help I'll follow the advice in the first article about tapering the shoe surfaces slightly so that they touch in the middle first.

I think this is a real problem. With EVs. Standard car brakes might need a rethink with bigger clearances and better shielding to keep the components dry. Even fancy alloy wheels don't help.

A mate has an ampera and has had to get brakes replaced through lack of use gumming them up. Whilst we need it for range, it seems regen brakes might save brake wear but corrosion and stickiness cause us more problems
If I drive conservatively for maximum regeneration I'm finding that it just doesn't keep the rust on the front discs under control, which leads to squealing and/or scraping (on the built up rust) even on discs that are only a month old.

When I brake a bit harder and don't worry so much about regeneration I'm not seeing a problem, so I'm reluctantly braking harder now to keep the brakes in good condition.
 

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I'd disagree with the rear drum.in our case....it's definitely the front discs that grab with an ear piercing shriek. But when it has decided to to keep the brake applied it the rear drums that have been on.

So why doe it grab ? I'm can't think of a physical.reason in our case except that the cars brain panics and thinks it's not slowing as it should due to.wet discs....and then slams the brakes on with pressure that the components wouldn't normally see.

It did it last night in the heavy rain on my commute home but stopped.when I put it in N and used friction only. My next stop in drive and it was back to grabbing.

It think it gets confused.
 

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I'd disagree with the rear drum.in our case....it's definitely the front discs that grab with an ear piercing shriek. But when it has decided to to keep the brake applied it the rear drums that have been on.
Squealing front brakes and grabbing front brakes are two different things... If you are sure the front brakes are also "grabbing" then you should check and replace the rubber bush on the lower slide pin and make sure that both slide pins are greased suitably with silicone brake grease - it made a world of difference for the smoothness of my front brakes.
So why doe it grab ? I'm can't think of a physical.reason in our case except that the cars brain panics and thinks it's not slowing as it should due to.wet discs....and then slams the brakes on with pressure that the components wouldn't normally see.

It did it last night in the heavy rain on my commute home but stopped.when I put it in N and used friction only. My next stop in drive and it was back to grabbing.

It think it gets confused.
It's nothing to do with computers, nor does the car "slam the brakes on" for you, you are pressing the brakes, ABS releases the brakes if a wheel locks, it doesn't apply them. (Traction and stability control can however apply brakes by themselves)

The reason why drum brakes can grab or lock on are explained on those two pages I just linked to - have a read of them. It's actually a pretty common problem with drum brakes, and it often gets worse in cold or damp conditions.

Cold causes the diameter of the drum to shrink, this can case the shoes to grab at the ends, and dampness can affect the lining material and increases the frictional coefficient of the linings, which can also lead to grabbing. All explained in those links...
 

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But it doesn't grab when the car is stopped in N. Stop in R and D with the discs dirty and it does. I agree it's not the ABS doing this but it has emergency brake assist which I think the car is triggering under these circumstances.

Otherwise, if it was a physical problem with the brakes - a la your rear drums - it would be all the time in every 'gear' position.
 

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Just because it doesn't happen all the time doesn't mean its not a mechanical problem. I don't know about your car but I know for certain that the grabbing, locking brake on mine is the rear left drum and that it's not related to any kind of ABS or emergency braking system.

Why ? Because when it is misbehaving (usually in cold or wet weather) it grabs and locks the rear left wheel even if I just pull the handbrake gently, which acts only on the rear wheels... which rules out everything you are suggesting including ABS, emergency braking assist and front brakes, as none of these things apply to the handbrake.

Next time yours starts grabbing or locking at very slow speeds try pulling the handbrake on gently instead of pressing the foot brake - if it still seems over sensitive or easily locks a rear wheel you have the same problem as me.

I'm just waiting for enough time and good weather to pull the drums off and have another go at them.
 

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Yes that's what mine was doing - locking the rear left wheel. Once I couldn't even get moving forwards with full throttle as the rear left had jammed on completely, I had to reverse (at a traffic light no less) to un-jam it! It's definitely the rear brakes doing this, contrary to what I initially thought.
The same thing happened to me today. It was wet but not cold. Had occurred intermittently but never locked up before. Glad I had read this thread previously as might not have the cop on to put it in reverse. The following car was very close.

Think it is the same rear left wheel. There is noise when it grabs which comes from the left side and when it locked up the rear dipped. Would expect the front to dip if it was a front wheel.

There is no sign of this in the wife's C Zero. Pretty sure she uses the brakes a lot more. A mixture a driving style and more stop start trips. May have to train her up. Not sure it would instinctively occur to her to put in in reverse. Although without a practical example and 30+ years experience may be wasting my time.
 

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I was going to investigate further on mine to see if I could fix it - however it has come right by itself recently. So I'm going to leave it alone until it starts playing up again. It does seem worse in wet conditions which suggests the shoe lining grabbing as the lining friction increases when the material is damp.

Either that or the grooves in the backplate lands need smoothing down. Not entirely sure now and without it playing up I'm reluctant to do anything to it because I won't know if I've made any improvement or not.
 

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Just be aware I had to file the "ears" at the ends of the pads back a bit (probably half a millimetre on either end) to get them to fit in the caliper! Not uncommon with 3rd party pads, but annoying nevertheless.
 
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