[Piers]

My car has just had its 2nd service at 34k miles. My idrive is showing 6k left on rears and 10k left on fronts before pad change. I asked them to check and reset it as per instructions on here...

They tell me that the idrive is the same on reset and that is that.

A mate who had the same car went over 60k, and he drove everywhere like he stole it, whereas for me, i am literally cruising all day.

Any thoughts? Is idrive right? is 35k about right for pads?

[SuffolkIan]

I did my rears at just under 40k when I drive said, they were about done, less than 5mm pad left. Just did the fronts, I drive was showing 5k to go, just over 5mm pad left and at least 2/3 worn compared to new pads, so I'd say it's not far off.

Ian

[Balster]

From my 2nd service last week:

Brakes pads are showing:
New /Actual/Usable/Rec'm
F: 14 / 10 / 9 / 3
R: 11 / 9 / 6 / 3

I drive says fronts need replacing in 3k and I'm on 31k

[HighlandPete]

Piers, what is the actual pad thickness? CBS can be well off, been there with my rear pads. Got down to a silly figure with about 9mm of pad thickness. Dealer reset the mileage, based on the actual pad thickness against mileage already driven. Has stayed much more accurate a countdown since the reset.

[IanS100]

I've done just short of 18k miles and definitely don't hammer the brakes, yet iDrive is telling me I only have 7k left on the rear brakes. The fronts are reported as fine. I've never had a car go through back brakes so quickly / quicker than the fronts, so I'm pretty sure it must be wrong.

[AP]

I have covered 22000 miles and mine states 70000 left on front and 130000 left on rears.
no idea of actual thickness but nothing brought my attention at the M.O.T.

[martin mustang]

It is down to your driving style, I realised my one last less with the Performance pack installed! Nothing beat having them checked physically if you think you not heavy on breaking.

[IanS100]

I'll check them when the iDrive tells me they need changing and either swap them myself if they're low, or get them reset if they're ok.

[The Beast]

Originally Posted by IanS100

I'll check them when the iDrive tells me they need changing and either swap them myself if they're low, or get them reset if they're ok.

iDrive is only a guide, the brakes have a sensor front and rear, I wait for these to light up before thinking about a change...

[Piers]

Originally Posted by AP

I have covered 22000 miles and mine states 70000 left on front and 130000 left on rears.
no idea of actual thickness but nothing brought my attention at the M.O.T.

This is what my friend with an identical car's idrive is saying!

[Piers]

Originally Posted by HighlandPete

Piers, what is the actual pad thickness? CBS can be well off, been there with my rear pads. Got down to a silly figure with about 9mm of pad thickness. Dealer reset the mileage, based on the actual pad thickness against mileage already driven. Has stayed much more accurate a countdown since the reset.

Pete, i asked them to check and reset, they said it was the inside pads that tend to wear fastest, and I cannot see those!

[Piers]

Can any mechanic do this? Order pads from BMW etc? Anything special?

[The Beast]

Originally Posted by Piers

Can any mechanic do this? Order pads from BMW etc? Anything special?

Yes, the wear indicators are reset through a programming screen in the instrument cluster. Google it and you will find a YouTube video showing how...

[m@rk]

My car was serviced last week (2nd service at 38k) and when it went in the fronts were showing 8k and the rears 15k so they have changed the disks on the front.

On my old 335D I managed almost 60k out of the fronts but of course it's not just about how you drive it but also the types of roads you drive on (stop start vs motorway etc).

[shiner]

Don't forget the 5 series is a two ton car nigh on.... Slamming brakes on from speed to get 2 tons to stop will wear the brakes out quickly if you are on them all the time.

My 535D at 18000 miles - I bought it as an AUC at 15800 - shows front have 6000 and rear 8000 left. So the previous owner was slamming the brakes on a fair bit...

When it comes to replacement I will get these done at an independent even though car is under warranty. No way paying BMW prices.

[Johnny Grabble]

Originally Posted by HighlandPete

Piers, what is the actual pad thickness? CBS can be well off, been there with my rear pads. Got down to a silly figure with about 9mm of pad thickness. Dealer reset the mileage, based on the actual pad thickness against mileage already driven. Has stayed much more accurate a countdown since the reset.

Like the electronic dipstick, which is frequently inaccurate, so it appears is the brake pad measurement, so the real thickness is of course the one to go by. AFAIK, if you wear them down to the limit, there is an additional warning which comes up on the dash, in addition to what the iDrive tells you.

[DDarkEnergy]

Second service 10 days ago:
Mileage 36000
Front brake pads 10mm
Rear brake pads 9mm

Idrive indicates
100,000miles front
70,000miles rear

[HighlandPete]

Originally Posted by Johnny Grabble

Like the electronic dipstick, which is frequently inaccurate, so it appears is the brake pad measurement, so the real thickness is of course the one to go by. AFAIK, if you wear them down to the limit, there is an additional warning which comes up on the dash, in addition to what the iDrive tells you.

I've tried to get to understand why the CBS for brakes in the F1x models seem to be so far off in many cases. My conclusion, it does appear the original algorithms for brake wear do not reflect all driving situations. I note some have had software updates.

Once the 2-stage sensor starts reading actual wear, we ought to be more accurate, with the final warning meaning we have a least got to a predetermined minimum thickness.

My question is, has anyone (with known pad thickness) simply ignored the premature countdown, to see what happens in reality? When you know there is say another 30,000 miles brake life, at the current wear rate.