2012 E70 40d I had the Service light come on a few weeks ago. I booked the car into a main dealer and they read the key and said the brake pads needed changing. They did an inspection and the fronts were 8mm and the rears 6mm. The computer says the fronts need changing in 300 miles and the rears in a few thousand. I declined to let them change them as I think that at 8mm there is more than 300 miles left in the front pads. Does anyone else agree? I am not sure how thick new pads are, but at a quess, I would say they are about 10mm, so I think that at 8mm the pads do not need changing. Why is the computer saying that they do though? Any ideas? Graeme.
New front pads are 13.8mm and rears are 11.8mm I think. Either way 8mm is a lot of pad. If you're able to measure them yourself that would be best, then you can measure the inner and outer pads on all wheels and know for sure what they are. The calculated change on the CBS is more often than not wrong, for some cars there was an improved calculation data that could be added via programming but if you're not under warranty it would be chargeable but would include bringing all control units to the latest software level. The other option is to get them reset and the cbs corrected using the thicknesses.
The old CBS issue, being way off. Had a similar issue with my rear pads, garage reset CBS as 8mm (measured thickness) is thousands of miles of use. Resetting took them back to over 30,000 miles again, much more inline with the wear rate for the first part of the pad. 3mm is the typical minimum pad thickness we'd safely run. Peter
Can I reset the CBS myself or is it a dealer job? I have looked at videos on youtube where the odometer button is pressed next to the speedometer and the brake service can be reset from there.
I know you can rest things on the e60 by accessing the 'hidden menus' [done it myself] and I'd assume the E70 at that age would be the same.
Had the same issue on my F30 335i http://bmwlander.co.uk/index.php?threads/brake-pad-wear-miles-remaining-on-i-drive-incorrect.600/
My brake pads must be growing. ;) When new the i-Drive told me 30K front and rear. Now after 11 months and some 15K miles the i-Drive says 45K front and 80K rear. Must be all down to my driving style - Hmm.
That's ok Graeme, hope you get it sorted. Peter provided some useful information regarding the 2 stage pad wear sensors. As in my case the dealer can amend the number of miles remaining but if you're outside the warranty period it might be worth checking the cost first!
They still wanted to change them at 6 and 8mm ? If they did I would report them to somebody. Thats appalling if they said they still need changing, and it just totally underlines why they are nicked named stealers. As Peter says, 3mm not less than 2mm. reset it and see how the reading drops.
Still find it unbelievable that they would considering changing the pads with 8mm of friction material left. Surely common sense would dictate that they should have instead investigated why the remaining distance was being calculated incorrectly :confused:
As a side point, I can completely understand when the garage flags up things like pad wear prematurely, if they know the car is heavily used and/or they know the user would rather get stuff changed in one visit, rather than a repeat visit a short time later.
One other thing that the inspection threw up was a loose rivet on the backing plate - only found by trying to push two pieces of the plate apart. They wanted to change the whole backing plate at a cost of £590! I suppose they thought that if the discs need to come off to change the backing plate they may as well change the discs and pads at the same time (£350 for the front discs and pads). I have examined the rivet and it is not causing any issues and I will just repair/replace the rivet rather than changing the whole backing plate - which looks in excellent condition. I will,change the discs and pads myself when I think the pads are down to 4mm or so.
The backing plate rivet issue happens quite a lot, realistically a run through with the drill and a new rivet will have it as good as new. Probably best to get it done before the rest go and it goes missing though lol. As for the pads, if it was me I would get the CBS value corrected because once the counter runs down you will have brake warning lights galore on all of the time and that's going to get pretty damn annoying for the thousands of miles before they wear out, another option would be to reset them for the time being and then ignore the counter and monitor the thickness yourself.
Thanks, I will replace the rivet(s) when I put my winter wheels on soon and do a reset and keep an eye on the pads
Just for info, minimum limit for brake pads on an MOT is 1.6mm I'm struggling to understand condition based servicing as much prefer an annual service. Easier to know where you are then.
Same here... if you stick to the speed limit it's quite difficult to wear them down... well that's my defence officer
