XSeries-forum

I've had the same treatment before at the stealers and it ain't only you getting bad service so chin up and ignore it.

Full procedure I assume on the BMW software to activate ABS as well?

Welcome to BMW!  It is unusual for a Master Cylinder to go, but there have been a few on here with internal MC piston seals leaking and allowing the pedal to keep moving under extreme pressure.

The normal 'bleed' procedure is under light vacuum if they are using the proper BMW device.

Thanks for the information.  Hopefully if the the bleed procedures don't cure it then any other part failure will be covered under my comprehensive insured warranty.  When I think about it I've probably not had cause to push the pedal that hard under constant pressure so if there was a master cylinder seal issue I may not have noticed anyway.

Regarding BMW's attitude, it's been like that for most of the last 6-7 years.  That said when I took the Mini in recently a technician recognised me, remember I owned the X5 and started chatting about it.  If only they were generally like that, it'd make a world of difference.

So I've been to collect the car twice and it's not been right twice so it's back with them.

I'll expand on things once it's sorted but would X5 owners mind trying starting the engine and pressing the brake pedal with constant hard pressure please?  Does it go down slowly to the floor?

I believe the main technician is trying his best to resolve it and even went to visit a friend who has one to compare.  Not by him but I was told yesterday that all cars do it so I tried our mini and it was solid as a rock.  I did leave on the basis that it might be normal but would like to know for sure but then the pedal immediately became variable on driving and went to the floor easily a couple of times so I headed straight back.  There is clearly something still amiss with mine but I'd still like to know if when stationary with the engine on you should be able to press the pedal to the floor albeit needing significant force so if a number of owners would try it we could get a consensus.  To me it seems there are no external leaks and if there's no air in the system then it must be fluid passing by a seal or valve.

trying to remember .....but if i remember correctly after i changed the rear caliper when i first pumped the pedal it felt "odd" compared to other cars i've done
on saying that it is all working well on the brake side so i'm not worried about it

Just tried my 4.6 the pedal is harder with engine off but when started the pedal feels a little softer (if thats the right word) but constant pressure it stays firm. So it doesn't sound "normal" to me.

For what it's worth Volvo had an issue with leaking servo's in the 90's which gave similar symptoms push the brake and it felt spongy and the pedal would settle under constant pressure.

Thanks.  I've been reluctant to accept that it's normal.  I just can't see any reason it would be and haven't noticed it before.  I agree that the pedal being rock solid with the engine off and slightly softer with it on is normal.  In any case once I drove it things got a lot worse so it clearly wasn't right.  The brakes still worked but the pedal went right to the floor more than once with nowhere near as much pressure i.e. within the bounds of normal braking pressures.

Does anyone have an X5 near Sale, South Manchester?  I'd like to compare the pedal.  It still doesn't feel right to me and goes down with moderate pressure such that I'm certain I would have noticed if it had done it before.

Sorted.  The local newsagent has one and was king enough to let me feel his pedal (fnarr fnarr).  Very useful reference point.

Ok.  So I have it back now for a few days but it still doesn't seem right so it shall probably be going back in.  Could any X5 3.0D owners try this please?  Drive along then bring the car to a gradual halt as if pulling up then without taking your foot off the pedal, push it to the floor.  Will it go right to the floor?  If it does, does it do so quickly?  Does it do it under moderate pressure?

I now accept that with pretty much any car if you start the engine pump the brakes a couple of times then push very hard on the pedal it will slowly creep to the floor or not far off it but mine will do this under light to moderate pressure and after coming to a halt you can keep pressing straight to the floor once stopped.

Anyone?

Would love to help mate, but my girl is in having a new gearbox fitted....

Thanks anyway.  My only other option is to try one for sale at a local garage but I don't really like pretending to be interested just to get a test drive though I could just explain and appeal to their goodwill.

I've been trying to remember to try this for you.....
So mine is a 3.0 petrol but I'd imagine it's the same brakes as yours
Pulling up to a halt and keeping pressure on the pedal it does slowly drop to the floor but at no time does it feel like there is anything wrong
I'm pretty sure that there isn't anything wrong with my brakes but I have recently changed the rear pads/discs and n/s caliper

Thanks.  With mine I can get it to do that by pumping the brakes at a standstill then applying moderate pressure.  If I bring it to a stop steadily then without lifting push harder, the pedal goes all the way down quickly (but not without resistance).  Does yours do that?  I think I shall probably have to drive another but its still helpful.  I'm trying to drive it as much as possible at the moment to see if the discs and pads wearing in and just driving it for a bit helps.