E320CDI W211 2006 Facelift Failed MOT on parking break

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Stocho

Active Member
Joined
Jul 4, 2009
Messages
414
Hi,

E320CDI, Estate, W211 facelift failed MOT for parking brakes performance.

How easy is it to fix this. How many hours of labour / what parts are likely to be needed? Any other jobs that would be advisable to be done at the same time if some major disassembly is needed?

Thanks for advice on this matter!
 
It might just need adjusting. Or more likely cleaning out, lubricating and putting back together, then adjusting. They hardly get used so sticking and corrosion are more likely than worn out shoes. Obviously check on the pads, discs and brake hoses / pipes whilst you have your head down there. An hour a side maybe? Some brake cleaner and brake grease needed.
 
The glib answer is 'how long is a piece of string...?' But these foot operated brakes have all sorts of 'issues' . I assume the failure was 'not holding' In which case it could just be a simple adjustment through the hole in the rear drums and a bit of lubrication in the mechanism in the adjuster cassette where the cable splits beneath the rear seat.

It could also be that the shoes have been dragging forever and have worn themselves and the drum surface out which would require new shoes and rear discs.

The basic adjustment/clean out is the first one to try.
 
Hi,

Thanks a lot for the replies. Even though the MOT mechanic, advice here and videos suggest there is a chance a fix could be simple I took it to the garage. The rationale (laziness and lack of time apart) for not even attempting DIY is that without measuring equipment how would I know (reasonably quickly) that I actually managed to fix the problem?

So it went to a very highly rated garage (essentially 5 start rating on Google) that also does MOTs and they tested performance after they did the work - so surely it would pass a retest I thought.. . Straight after the garage for MOT it went .... and it failed!!! (Well MOT center were clever enough and kind enough to do a free pre-MOT check on the failed items so does not count as a fail but a fail in essence.)

The invoice for the repair was just over £100 and details all the work done very well:
Investigate cause of poor handbrake performance
Remove rear wheels and inspect
Drop down exhaust shield to gain access to handbrake balancer mechanism
Free off and lubricate balancer mechanism
Refit heat shields
Lubricate OS and NS handbrake actuators
Buff up adjust handbrake shoes
Refit Wheels
Carry out handbrake efficiency test on rollers - OK

The MOT test center produced the following efficiency printout that states that N/S is only exerting a force equivalent to just 95kg which is a big failure.

My own investigations:
Even before the repair I tried stopping on various sloping roads, applying parking brake, putting gear selector into N and observing whether the parking break is able to hold the car. I would say performance now is a bit better than it was before. On a very steep slope the parking break is holding the car if I press it really hard (most women and frail men would not be able to press so hard) when applying it. If I do just a comfortable press - it does not hold the car on very steep slopes.

So the question is how could such a situation arise (when a garage that also does MOTs says it is fixed and tested while MOT center does not agree and by a massive margin?
Are there rules on how hard should testers press when testing the car - with all the force they can or just a comfortable press?
Perhaps the garage that repaired it tested it while in Park Gear? Are there rules that it needs to be tested while in Neutral - after all it can not be parked in Neutral (unlike manual cars that can be and with manual cars parking in gear has it own dangers that are not heir with automatic)?

Also based on the test result below (that tested all brakes - not just parking) do I have a problem with OS Front brake as its performance 29% below N/S and on par with rear brakes that are supposed to be much weaker?


Any other advice on what to do would be welcome.

Brake Test.JPG
 
Take it back to the place that did the work and show them the "retest" fail - suggest that they need to have another look at the n/s brake. My bet is that the n/s just needs adjusting so that it activates in synch with the o/s. Given those results it would have been obvious that the n/s is not working properly even without measuring equipment and as a MOT centre they should know better. It would of course make your life easier if you used the same place to repair the brake and do the MOT. The test needs to be done in neutral - you need to be able to turn the rear wheels to make sure that the brake is not binding when off and then check that they don't turn with the brake on - not easy if the car is in park.
 
The rear shoes are inspected, so in good order we assume.
Components are lubricated, so no seized we assume.
The balancer should then be applying equal pressure to each side.

Likely one side isn't adjusted correctly, and only a part of the shoe is pressing on the drum.

Repair garage haven't done it right, surprisingly.
 
I had an mot inspector (little bloke) tell me on my 211 estate that the handbrake was not holding properly on an advisory on mot, i told him there was nothing wrong with it. i did nothing but put the seat forward a bit on the mot and it passed with nothing wrong with it for the next 6 years. Tell him to grow up if he's little.
Take it back with the note they give you to the place that had supposed to fix it.
I have learnt over the years for £100 its not worth messing around with, you should have got them to fix it and jobs done, you put yourself through all this, we have all done it, and i know £100 is a £100 but take the easier way through life and sleep better.
I hope you get it solved ok:thumb:keep us informed.
 
Why didn't you let the highly rated garage do the MOT?

Several reasons:
1. I prefer MOT places that you can just turn up. These days many garages that used to be like that operate booking system with many booked days or even weeks in advance.
2. I prefer either MOT only garages or garages I personally tried before and found to be fair with MOT. So the place I went to is 30 minutes away actually but they fit into this category and number 1 above. they do just MOTs.
3. I found the garage that did the repair after the MOT failure. So after the car failed MOT I first phoned my usual MB independent specialist (hoping that he would also cover advisory and service as 1.5drive to see him - each way!) - booked 10 days in advance. I then tried other garages I used in the past - again heavily booked including those that back a couple of months ago had great availability. And then I started searching on Google Maps selecting only those that have quite a few good reviews and had to phone about half a dozen before I found a garage that could see me within three days... They have 4.9/5 starts on Google with more than 50 reviews - quite an impressive record ... but still had this with them....


...and according to their website they were supposed to be working haf-day today. So woke up at 7am instead of 11 or 12 and have been phoning them - hoping that if they fix it today I could take it for retest today. But no answer... How dis they manage to get those 4.9/5 ....
 
Maybe the mechanics work on a Saturday but the office staff who answer the phones don't?
 
Maybe the mechanics work on a Saturday but the office staff who answer the phones don't?

It is a small business 2-3 mechanics and no office staff. I dialled them about 10 times during a course of about three hours. I did consider this possibility that may be something happened to their phone line but then the thought of driving to them with the, probably, 95% probability of finding the shut door on a cold winter morning would be a further increment to the disappointment. The answerphone message says that due to COVID opening hours might be different than advertised (without stating what the new hours are), though wearing good masks (instead of none) would seem to offer a much better protection both from COVID and other hazards such as brake dust than cutting hours...
 
Spoke to the garage they adamant that it was balanced when it left them and telling if it is really the case that it became so bad probably new disks and shoes are needed. But when I asked them whether they looked like requiring replacement when they did the work - they said they looked fine. There was some corrosion but they cleaned it and said it is normal as there is not much friction there (unlike with friction of normal brake pads on discs). They said adjustment is unlikely to help.

There was one thin that they said that caught my attention. They said that they tightened the adjustment and released it by five clicks. As I kind of remember reading somewhere that it should be two clicks, I challenged them on that. But they said that they tightened it much more than usual, not just to the point it stops but until it just would not go any further with any force, and if they released it by just two clicks it would bind... Are they correct on the number of clicks? Is there MB manual on that?

Agreed I will take it to them tomorrow nd they will retest on rollers.
 
There was one thin that they said that caught my attention. They said that they tightened the adjustment and released it by five clicks. As I kind of remember reading somewhere that it should be two clicks, I challenged them on that. But they said that they tightened it much more than usual, not just to the point it stops but until it just would not go any further with any force, and if they released it by just two clicks it would bind... Are they correct on the number of clicks? Is there MB manual on that?

And actually is it how professional mechanics are supposed to do - tightening up to the maximum and then back off a set number of clicks be it 2 or 5? I thought it was more of a rule of thumb for a DIYer and mechanics would have some better means such as tightening fully than releasing the minimum amount possible that does not result in binding when the brake is released?
 
Also they did say there was some rust which they said is normal as there is normally no dynamic friction between the show and the disc. I saw advice on the internet ... to drive a bit with the parking brake on as this effectively grinds off the rust between the shoes and the discs. Is it wise to do that or it has a risk of totally wrecking the handbraking system that a mere adjustment (that is required anyway) will not fix?
 
Found this post. Could it be this?
 
There was one thin that they said that caught my attention. They said that they tightened the adjustment and released it by five clicks. As I kind of remember reading somewhere that it should be two clicks, I challenged them on that. But they said that they tightened it much more than usual, not just to the point it stops but until it just would not go any further with any force, and if they released it by just two clicks it would bind... Are they correct on the number of clicks? Is there MB manual on that?

My experience is that if you follow the recommended number of clicks the brakes are rubbish. I adjust them until the wheel binds and then back off only enough clicks to allow the wheel to turn freely. On my 190e I recall it was 7 clicks but if I did that the parking brake was hopeless. Now that was one of the very few MB models that had a conventional pull up handbrake which mean't you couldn't apply as much force as a foot pedal so adjustment mattered and it was easy for me to detect that the "only enough clicks to turn free" method worked the best. I've applied the same approach to my W204 without problems.
 
Today took it to the garage that did the repair.

So when they put "Buff up adjust handbrake shoes" I thought "buff up" meant that they took the disc off, and sanded the shoe lining and therefore lubricated mechanisms inside the drum, saw the state of shoes and so on.

But what they meant is they drove the car with handbrake and therefore today for the first time they took the disc off and found:
1. One Show has a crack and the other quite uneven surface
2. The mechanism that is at 9 o.clock (on rear near side) )was seizing - probably it is the root cause of all the problems as I do remember that handbrake sometimes did require several pulls to fully release.

The insisted that the proper repair is to change discs pads and shoes. I understand how pads and to be changed when discs are changed - as they provide main, and dynamic braking. I.e. they don't just bind to the disc - they actually slide on it when braking. But with parking brake shoes - do discs (that are not even 25% worn) and pads that are less than 50% worn have to be changed? They said that if I want to do shows only without discs and pads they would do it only on condition that I do not come back to them again if it does not pass MOT.

Also I noticed that when they were removing the disc they allowed caliper to hang on braking pipe hose - not supported by a stand / hand on wire/rope (as I always do). Is it ok or is it a sign of recklessness?

So eventually they just spayed the mechanism that was seizing in the drum and adjusted the handbrake and basically there is some chance it might pass retest (that runs out today) and then have to think about long term solution.
 
Well i would say just replace handbrake shoes. Sounds like a right bunch of cowboys to me, once that's done you know never to go there again.
 
The car has passed MOT! So the reason for the problems with parking brake performance was partial seizure of the mechanism located at 9 o.clock in the drum (on Near Side) that in turn, probably, caused deterioration/cracking of the brake shoe lining. Lubricating the mechanism and adjusting was sufficient to get it to pass MOT, even though brake shoes are far from being in ideal form.

Thanks a lot to everyone who contributed to the discussion!
 

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