[Brakes] Think this is an Mot fail? Oh no!

[Gravity]

Bought my M59 in March, just after it had a new Mot. It's a 2008 model.
The brakes felt reasonable, but nowhere near as good as my B9, so they were on my list of jobs to look at. I had no real worries - after all, it had recently passed its Mot and had only covered 1600 miles since.
Yesterday, the car began jumping around every time I braked, so I gingerly got it home, stripped out the front brakes,  and this is what I found:


Some Mot! The pedal probably felt firm to the tester, but obviously the brakes hadn't been looked at. That is about the worst I've ever seen on front discs. Both discs have reasonable wear on one side, but the other side has never seen a pad, and just looks totally shot.

As it's the inner side of each disc, I suspected stuck or stiff calipers in their carrier, so as they were already removed, I began stripping the carriers down. Yes, there was a little stiffness, but I could slide them in and out without much effort. The pads were in poor shape, with the backing separated form one pad each side, and uneven wear as you would expect, given the disc condition. Like so:


So I've ordered new discs and pads from ECP, and they should arrive today. They had a 50% discount offer going (still in play until midnight, if anyone wants brake parts) and I got the lot for just £33.

My concern is this - Is this a known weakness on the M59, or a one-off?
I suspect it's a one-off. There was a bit of bodgery present, because there were odd disc securing set-screws on one side and none at all on the other side. I had to re-tap the threads on the side with no screws so that I could fix the disc to the hub properly. Whether a previous owner used odd pads, or new and old mixed, I've no idea - but something caused this and I don't suspect stiffness in the carrier, because it didn't seem too bad.

[Matt Haigh]

Good work on your behalf to sort this little lot out for £30, just fortunate you hadn't needed to emergency stop recently.

[Gadgetman]

Honestly, I'd look at the way the pads were mounted, because this really requires the pads not to move at all.
Even With 'very stiff' calipers, the pistons should be able to move when you apply max braking Power.
The other possibilityy is that the previous owner was Hypermiling all the time, so never used brakes.

I believe the MOT fail is at least 1/4 of one side of the disc being corroded.
Also, that's on the 'inside' and that's EASY to spot when the car's up on the ramp. And the had to og up on a ramp or lift for them to check the play in the steering and suspension.
Frankly, here in Norway, I'd have taken the discs to the people overseeing the inspectors, because this is so bad that it's criminally negligent.

[Gravity]

I agree about the Mot being bad, but this was done with the last owner.
As far as the pads are concerned, I also have a Fiat Panda that regularly requires de-corroding of the sliding surfaces so that the pads move freely in their grooves. That's a known Panda problem.

This was not especially evident with the Berlingo. The corrosion that would often make the pads 'stick' was not bad at all - which made me ask if this was a known weakness with the Berlingo braking system. I honestly can't see one single reason for this one sided wear, so I'm guessing that the last owner re-used old pads or mixed pads of different makes.

Anyway, I'll make regular inspections once the new discs and pads are fitted, and monitor the wear.
Once bitten, twice shy!

[polar]

When your mot was carried out the tester could not fail the vehicle on a corroded disk if the brakes met the required readings on the brake tester including imbalance.

The test has changed now to include corroded disks.

Also remember the tester can only test what he can see and the inboard side of the disk is difficult to see.

[geoff]

 I also have a Fiat Panda that regularly requires de-corroding of the sliding surfaces so that the pads move freely in their grooves.

 if this was a known weakness with the Berlingo braking system.

 1/ Try applying a rust converting fluid to the ( cleaned ) rust affected areas and then use some heat tolerant 
      lube to solve the problem. Sounds like Fiat has cut costs on material quality in this instance.
 
 2/ Not an issue on the two M59's I've owned, funnily enough I've just fitted new front discs and pads on 
     my current M59 a couple of weeks ago and no issues there, all I needed was to use a brass brush to clean 
     the dust and dirt off with no rust anywhere. All components evenly worn.

[Gravity]

 2/ Not an issue on the two M59's I've owned, funnily enough I've just fitted new front discs and pads on my current M59 a couple of weeks ago and no issues there, all I needed was to use a brass brush to clean  the dust and dirt off with no rust anywhere. All components evenly worn.

That's the norm, isn't it? Very glad that this does not seem to be a Berlingo characteristic.

Never seen discs quite like this before, and as they were bodged onto the hub I'm thinking that a previous owner did something stupid, like reused mismatched pads, or soft and hard pads together. Not sure what to think, because the usual suspects - corrosion, pads sticking in their grooves, stuck carrier (with one pot calipers) - don't seem to apply. Maybe the guy even put old, worn discs on for some reason.

Anyhow, it'll now have new discs, pads and a complete service of all components, so I should not get any more trouble. Still waiting for ECP to deliver. They're getting slower than they used to be.

Thanks for your reply.

[jj9]

The pads should sit in stainless steel clips that fit to the caliper carrier before the pads go in, did yours have these?

https://www.eurocarparts.com/ecp/c/Citro...214&000416

The area where the clips sit on the carrier may need a good de scaling to get any corrosion off, a wire brushing isn't always enough, tapping it with a sharp pointy implement will chip any stubborn corrosion off.

With the clips in place the pads should be a snug fit but not tight, you should be able to move them by hand. 

Remove the slide pins from the carrier, clean the pins and the bore and relube, make sure they are smooth in operation over their full travel.
One of the sliders may have a rubber insert, (think it's the top one) this may be better removed as it can become very tight in the bore over time.

Could be a lazy caliper piston, check the piston is free to move, you may have pushed it back but I would pump it out and push it back in a couple of times to give it a work out. 

Remember if you have both sides stripped both pistons will pump out!


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[Gravity]

Hi jj9. Thanks for your comments.

The clips are all in good shape, and were fitted correctly.
Everything you have mentioned has already been checked out, because - like you - I have rebuilt plenty of braking systems over the years, and know what to look for.

I agree - the rubber slides on the carrier pins are a nuisance, and supposed to be there as dampers to stop 'chatter'. I throw them away and VERY LIGHTLY lube the pins. Too much and you end up with 'hydraulic lock' and the pins refuse to go the full travel.

I'm convinced it was a previous bodge up that wrecked the pads and discs. How the Mot tester missed it all - well, that's his problem!

ECP just confirmed that delivery of all new parts will be next Tuesday. They used to deliver next day! I've put a plastic seal under the master cylinder cap, so the pistons can't creep.

I suppose I'd better check out the rear brakes while I'm at it, and then bleed the whole system (got a pressure bleeder - piece of cake).

[jj9]

Well if everything is moving and you can see no problems the discs as you suspect have obviously been like that for quite a while.

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