General MOT failure Tyres + Brakes

[Lou]

Hi,

My Ulysse 2.2 jtd failed it's mot on Friday, as far as I can remember it's the first time iv'e had an mot failure. I'm partly annoyed as it's the same garage that serviced it (mini service only) only 4,000 miles ago and the tyres were apparently fine then but now both offsides were worn. I didn't think they were but then I'm no expert. The main pain here is that I have ended up with tyres that I don't know much about (Marangoni Verso 100H XL) plus I could have got them cheaper. The only other alternatives they had were Pirelli's which were really expensive. So my first question(s) is; has anybody heard of these tyres and do they wear quickly? and at what mileage have most of you had to replace tyres? Mine have done 24,000 miles which probably is not bad.

The other failure, and this is the one I don't understand is on Front Brake Imabalanced 3.7.A.2e It was 30% and is listed as dangerous on the mot failure certificate. I discussed this with the tester saying that I would have expected some kind of pulling to the left or right if this was the case (I am extremely sensistive to changes in braking performance and apart from a slightly longer pedal travel I have felt no change), he said I would not and that 24,000 miles is very good for front brakes on an Ulysse as they normally go at 14,000 miles. He said as they could not take the wheels off on an mot he could not tell me whether it was brake pads or not but that they would have to change them and see. Now that figure I find hard to believe. I admit it's my wife who drives it most of the time and she is easy on the brakes so they may last longer but the cars done really well if one has got an extra 10,000 miles out of the front pads. So my next question(s) is has anybody got any experience of this failure? and at what mileage have your front brakes gone? Also does the dashboard warning actually come on when the pads are worn or is it it like every other car I have owned where the light never comes on as the sensors gets clogged with brake dust and the light never comes on? The car has now passed with new front pads...surprise surprise.

Lou

 

[Pat H]

Check the brakes disc's yourself. Our have just been replaced (by me) at 67,000 miles.
But for the last 30,000 or so I've been regularly grinding off the outer lip that develops. This lip catches the pads and makes a scraping noise as well as interfering with the braking force. But as long as the disc's are not down to the wear limit (shown as a flat on the edge of the disc) they should be fine.
This is a common "nice earner" for garages as most people just do what they say they need to do for safety. Garages aren't interested in getting the maximum life from components. They'd rather charge for new!

Our first Uylsse also failed on disks at 20,000 miles and after a lip grind was sold at 60,000 miles with disc's still ok.

 

[Lou]

The problem here was that my tax disc was also due so I needed to have it sorted. It's a shame as it is going in for a 5 year service plus cambelt change next Friday with somebody who I have only just got back in touch with and he would have been honest with me. As it is I am going to ask him to double check that the pads are new because at the moment it is not braking as well as I would expect. This could be due to the pads needing to bed in but they are definitiely worse then before the change.

 

[Pat H]

If was just pads and not pads and disc's then 14,000 is probably about right.
They should have a warning light that comes on that is triggereds by a wire bedded into the rad material that shorts to the disc metal.
Howwver what I don't understand is pads work till they run out and the metal backing hits the disc . Efficency then drops and the disc's get damaged.
Worn pads don't cause unbalanced braking unless so seriously worn they have worn right down.
As always best to ask for any parts they replace to be returned for your inspection. Not that they can't just pass off anyones parts to you but if they are the wrong type it's clue.
I always have my MOT done at least a month early (don't forget you can have the new certificate dated from the expiry date of the last one so you effectively get 13 months)

 

[NumanR]

Front brake imbalance is due to uneven braking effect on both front wheels and can be caused by contaminated friction linings, (semi) siezed caliper pistons, or sliders, hydraulic faults, corroded discs etc. If the brake pads have been fitted on older discs then the brakes need to bed in and this can taake up to 150 miles depending on how bad your discs are and the type of driving you do.
Garages have an MOT minimum pad thickness of 1.5mm, below this and the pads fail, likewise if the pads are not visible during testing, but when stripped for repairs they are discovered to be below 1.5mm, the garage has to fail them if retesting as they are known to be below requirements. Hope this explains a little about the MOT, brakes and why garages do what they do.

 

[Pat H]

But Lou was told the brake pads were worn and that caused the imbalance. Not siezed or contaminated just worn.
And if new pads were fitted to old discs how comes the imbalance got better when by rights they would need a good few hundred miles to bed in first.
I think every accepts things fail and need replacement it's just less then nice when what your told makes no sense.

 

[Lou]

The pads were visible as they did say they looked a little bit on the thin side before they took the wheels off. The bit I am confused at is that I would still have expected an element of pulling if there is an uneven brake load and I was not getting this. Also going back to the new brake pads I now have, every other car that I have owned that has had it's brake pads replaced has usually resulted in the brake pedal travelling less and if anything the feeling is that the pedal feels hard with reduced braking which then improves once they have bedded in. That's why I will get this checked when it goes in next Friday. I can't believe for one moment that they have not been changed as this would be really foolish for the garage to do. Unfortunately I do have a love hate relationship with garages, Iv'e been lied to too many times over the years, usually by dealerships which this one was not, but nevertheless I am always suspicious.

 

[party7uk]

Have you checked your discs for lips and slight ripples on the face of the discs, if they have that may be causing the pedal travel, the pads need to wear to the shape of the discs.
As for brakes out of balance it all depends which side is pulling the most,
the brake test is done on level ground but the roads we drive on have a camber which could hide the imbalance without you noticing.

last comment the tyres ,you said you had a sevice 4000 miles before test ,
in that time with speed humps,pot-holes and tyre pressures the outer edges can wear very quickly putting them below 1.6mm within 3/4 of tread.

 

[party7uk]

Check the brakes disc's yourself. Our have just been replaced (by me) at 67,000 miles.
But for the last 30,000 or so I've been regularly grinding off the outer lip that develops. This lip catches the pads and makes a scraping noise as well as interfering with the braking force. But as long as the disc's are not down to the wear limit (shown as a flat on the edge of the disc) they should be fine.
This is a common "nice earner" for garages as most people just do what they say they need to do for safety. Garages aren't interested in getting the maximum life from components. They'd rather charge for new!

Our first Uylsse also failed on disks at 20,000 miles and after a lip grind was sold at 60,000 miles with disc's still ok.

never just go by the flats on the discs as discs never wear evenly, the only way to be sure is to measure the thickness of the discs across the face.
If you have a lip on your disc (above min ) and your fitting new pads then the best thing to do is have the discs refaced. only problem with that is finding someone with the equipment to do it.

most garages measure discs when doing a brake check or service, if the discs are near min or below min they will advise replacement.

to many people replace their on pads without measuring their discs then wonder why they suffer with brake fade , pulling ,spongy pedal or worst crashing.

Its to easy to blame garages but when you see the state of alot of cars when they come in for a service/mot and leave with only standard service items replaced and get it through the mot, its scarey.