[M3-FAST]

Had a couple of strange incidents today with the brakes on my 'vert

Drove it out of the drive this morning and when I braked at the end of my road the pedal felt 'strange' - I was only going slow (10mph ish) and the next time I braked it felt ok. Carried on to work and when I pulled into the empty car park I did a bit of a brake test and slammed 'em on hard at 30mph. Car stopped on six-pence with the ABS working OK, etc..

Thought little else of it until this evening!

Drove out of the car park and up to the end of the road where I braked as usual for the T-junction onto dual carriageway. Brake pedal was rock solid and the car just did not want to stop. Pumped the brakes and got it to stop. Luckily there was no-one at the junction otherwise I would have instigated a rear-end shunt This was obviously the same feeling I got this morning but at a lot lower speed.

Drove it home and all seemed OK again for the rest of the journey. BMW Assist coming out first thing in the morning (no tech's tonight and they will simply send the local recovery firm to tow it away). Anyone got any ideas or experienced anything similar?

[Snooky]

Red - this is too spooky mate. I logged on to seek advice for two strange braking moments in my 335i coupe. This morning I was driving out of our estate and went to stop at the mini roundabout and nothing happened at first when I hit the brake. I had to really shove it to the floor to stop from, say 20mph. The poor guy on the roundabout got a right fright (not as big as me though).

I did as you did and had a couple of safe 'tests' and it worked okay. Seemed fine this evening on my way home. I had one other slightly 'spongey' braking incident last week.

Only 9,000 miles on the clock - any ideas?

[beemerbird]

Paul, what a bummer!

You say the brake pedal was rock solid when you came to the 'T' junction which implies an ABS fault, but then you said you had to pump the pedal to get the car to stop.

ABS system working on a series of electronic sensors and valves constantly monitoring pressure within the braking system - possible failure of valves to open and over pressurising the system, causing the brake pedal to feel solid? Pumping the brake pedal could have opened the valves/adjusting the pressure of the system and or reactivated the sensors.

Servo failure usually indicates low pressure within the braking system causing excessive pedal travel normally due to faulty diaphram (if that's how BMW servo systems operate?).

No ABS/brake warning lights then?

Either way, if they're coming for it tomorrow it will be interesting to see what the problem is when the stealer solves it. Good luck.

[M3-FAST]

Originally Posted by Snooky

Red - this is too spooky mate. I logged on to seek advice for two strange braking moments in my 335i coupe. This morning I was driving out of our estate and went to stop at the mini roundabout and nothing happened at first when I hit the brake. I had to really shove it to the floor to stop from, say 20mph. The poor guy on the roundabout got a right fright (not as big as me though).

I did as you did and had a couple of safe 'tests' and it worked okay. Seemed fine this evening on my way home. I had one other slightly 'spongey' braking incident last week.

Only 9,000 miles on the clock - any ideas?

How Bizarre!!!

Mine has done 10k miles - what is your build date out of interest - mine is April 07.

Are you going to notify BMW then?

[M3-FAST]

Originally Posted by beemerbird

it will be interesting to see what the problem is when the stealer solves it. Good luck.

Ha ha - more chance of platting fog than my dealer fixing my car first time (or even at all!!)

Defo a strange fault, and no warning lights either, which means the computers think all is well!

[Snooky]

Originally Posted by redE93cab

How Bizarre!!!

Mine has done 10k miles - what is your build date out of interest - mine is April 07.

Are you going to notify BMW then?

I am going to phone the dealer tomorrow and get them to have a look. I will give it a good test again in the morning before I need to use it in anger. Just re-reading your initial post and I had the same feeling - if there had been another car in front of me at the roundabout I would defo have rear ended it. No warning lights on mine either.

My car was a factory order delivered on 1 March 2008 so I guess it was built late January-ish.

Quite worrying really

[SixDegrees]

I had this 2 -3 times of late. Putting down to damp disks/pads during this wet n windy time... dampness forced in behind the pads by wind.

The fact that a few pumps of the pedal sorted it confirms to me that its a disks/pad thing and nothing electronic or mechanical. Its like when you wash the car and move it right away, or dirve through deep water.... some brake pumping is required to dry the disk/pad out.

If this was to happen after driving / braking for a few mins, and not after start up (car sitting for a while) then I'd be worried, but its only ever (me) after the car has sat over night or in car park during the day at work. Plus, can't be happening to random folk in different cars in different locations over the country within the space of a few days.... when we're all having the same (ish) weather.

[SixDegrees]

Originally Posted by Snooky

Red - this is too spooky mate. I logged on to seek advice for two strange braking moments in my 335i coupe. This morning I was driving out of our estate and went to stop at the mini roundabout and nothing happened at first when I hit the brake. I had to really shove it to the floor to stop from, say 20mph. The poor guy on the roundabout got a right fright (not as big as me though).

I did as you did and had a couple of safe 'tests' and it worked okay. Seemed fine this evening on my way home. I had one other slightly 'spongey' braking incident last week.

Only 9,000 miles on the clock - any ideas?

The wee roundabout with the pointy thing or the one at the start to Adambrae. Its happened to me at both in the past week, but I only brake reversing out the drive which won't be enough to get rid of any moisture in the gap (disk/pad) so its all up hill to the wee r/bout or out to main road.

[M3-FAST]

Kinda makes sense, but in almost 20 years of driving, I have never had brakes fail in a car just because it has been standing in the rain overnight or during the working day.

It was on both occasions the first 'braking' that was at fault. Subsequent 'stops' were all OK.

[Snooky]

Originally Posted by SixDegrees

The wee roundabout with the pointy thing or the one at the start to Adambrae. Its happened to me at both in the past week, but I only brake reversing out the drive which won't be enough to get rid of any moisture in the gap (disk/pad) so its all up hill to the wee r/bout or out to main road.

The wee roundabout with the pointy thing SD. I will watch carefully for you in the morning then

I did wonder whether the wind/rain might have something to do with it - it was a little bit like Ihad driven through very deep water - I wasn't expecting it though as you would always pump the brakes if you go through water. Will keep an eye on it over the next few days.

[Z4 Beemer]

If the brake pedal was hard does it not suggest a fault or some kind of failure with the servo, i.e. a vacuum hadn't built up...? This does sound worrying though. Hope you get a good explanation and some action from the dealer.

[M3-FAST]

Originally Posted by Z4 Beemer

If the brake pedal was hard does it not suggest a fault or some kind of failure with the servo, i.e. a vacuum hadn't built up...? This does sound worrying though. Hope you get a good explanation and some action from the dealer.

This is just how it felt - like the servo assistance had disappeared.

I DO want a good explanation - my missus is 6 months pregnant and drives it regularly as well as me ferrying around my 9yr old lad. Brakes were not one of the optional extras

[MIKEYBMW1]

now thats not good.

[dxb335d]

Hmmm, not good. want to hear more on this.

You guys due fluid change?

[SixDegrees]

Originally Posted by redE93cab

Kinda makes sense, but in almost 20 years of driving, I have never had brakes fail in a car just because it has been standing in the rain overnight or during the working day.

It was on both occasions the first 'braking' that was at fault. Subsequent 'stops' were all OK.

Its not uncommon in some VW (MK Golf), Minis, etc. In days gone by, before I knew better, I take the car through the car was (MKIV Golf) and you'd effectively have no brakes for a few yards.... after the 1st time you exit the gaage with no brakes (following car wash) you learn quickly to drive with foot on barke for 20ft... same as you do when driving throug deep water!

Because its onoy the 1st REAL braking that is the issue and subsequnet stops are OK, then I can't see any other logical explanation. Plus the fact that we're all experiencing it and we not related through car age, model, brake set up, location, etc etc only time of year, weather and its the 1st braking.

Anyway, would be good to see if anything comes up from a check at the dealers.

I've covered 8.5k miles and this is the 1st time this has happened. But I do agree it does feel like no servo, but thats the same feelinga s having wet pads, ie solid feel but nothing happens, then release and try again et voila, brakes back to normal.

[M3-FAST]

Originally Posted by dxb335d

Hmmm, not good. want to hear more on this.

You guys due fluid change?

20 months old and 10k miles - would not have thought so and surely the lack of effectiveness would be more consistent, and maybe after high motorway braking from speed?

[beemerbird]

Originally Posted by Z4 Beemer

If the brake pedal was hard does it not suggest a fault or some kind of failure with the servo, i.e. a vacuum hadn't built up...? This does sound worrying though. Hope you get a good explanation and some action from the dealer.

Gordon, it's the opposite with a faulty servo - the pedal would go down to the floor because of a lack of pressure ie vaccuum. I've experienced it before on a car.

[Dougie335]

This is really strange. I was out with the wife shopping as usual at the weekend and the same thing happened twice. It was pouring down so I just took it that it was water on the disc's. On both instances it was just after setting off on a journey. Even though I pushed quite hard on the brakes it took much longer to stop. Just felt like the pads were not gripping the disc's. This is my third 335i in a year and a half and I don't remember having it on the first two.
I thought we had brake drying on the 335i's.

I'll keep watching this post with interest.

Dougie.

[- Paul -]

Weird - happened to me today - brake's just didn't want to work then were ok. Brake soft if pressed normal (when stationary) but hard if pressed hard (if that makes sense)

[M3-FAST]

I do think you (we) should all make your local dealer aware of this.....

At least then if BMW make a history of 'faults' then it will show up a number of cases rather than just a few random ones.

Strange thing also is that in 20 months and worse weather than this, my car has never done it before either?

I have been promised a call between 6:30-7 am (oh joy) for the tech to book an appt. so hopefully will get some answers tomorrow?

[M3-FAST]

Right, BMW Assist arrived this morning at 8am and the tech reckons it is the vacuum pump at fault. After a couple of phone calls it appears there are two cases on PUMA that it might be.

First requires replacement of the vacuum pipe and vacuum pump

The other requires replacement of the brake servo.

Until the dealer has done some diagnostic work, they are not sure which fault it will be, although the tech is sure that it is the vacuum pump. He said he has had another one this week on an auto and this stopped the car starting after it was stationary for some time, as you have to have yur foot on the brake before an auto will start.

Either way, all you guys who are experiencing the same fault, I would get on to your dealer asap as there are possible issues with the braking system that IMO need sorting

Vauxhall Vectra from AVIS is on it's way - I will keep you informed as to what they do to fix it

EDIT: They delivered a brand spanking new LCI 320D M-sport Auto E90 so happier

[E92 LeMans]

Well it is good to know it is getting sorted out and still got a beemer to drive.