E91 2007 Stiff Brakes MID DRIVE

NedPuckM · 07-09-2019, 09:34 AM

I bought an E91 a couple months back without warranty (bad idea, cost me a pretty penny since...) and I've had this issue occur three times now.

Very occasionally when driving, the brakes will stiffen right up, as though the vacuum in the brake servo has failed suddenly. It switches between working and not working throughout the drive, which makes me unsure as to what it is as I thought if it were a brake servo fault, wouldn't it simply not work?

Just had a mechanic check the vacuum lines and he said there's a TSB from BMW saying the valve in the pipe that goes to the servo seizes up occasionally, and then didn't give me a solution...

Is there anything I can do about it? It seems super dangerous to be driving round with this possibility - it last happened when I was doing 60 round a country bend!

Any help would be great, cheers.

therealdb1 · 07-09-2019, 10:21 AM

If there is a service bulletin and the mechanic knows about it surely he must know what is involved.
Did you actually ask him what can be done rather than expecting him to tell you?
If there is potentially a faulty valve in the servo line presumably this is the place to start.
If your mechanic does not know what to do or is unable to help find someone else that is more knowledgable about BMW's and get them to take a look before you hit something / someone!

NedPuckM · 07-11-2019, 08:59 AM

That's what I thought, and we'd discussed it before so I assumed if there was a potential solution he'd have let me know...

Either way I've messaged him and he's gonna get onto BMW to find out what can be done.

07-09-2019, 09:34 AM	#1
NedPuckM Registered 0 Rep 2 Posts Drives: 3 Series - E91 Join Date: Mar 2019 Location: UK iTrader: (0)	E91 2007 Stiff Brakes MID DRIVE I bought an E91 a couple months back without warranty (bad idea, cost me a pretty penny since...) and I've had this issue occur three times now. Very occasionally when driving, the brakes will stiffen right up, as though the vacuum in the brake servo has failed suddenly. It switches between working and not working throughout the drive, which makes me unsure as to what it is as I thought if it were a brake servo fault, wouldn't it simply not work? Just had a mechanic check the vacuum lines and he said there's a TSB from BMW saying the valve in the pipe that goes to the servo seizes up occasionally, and then didn't give me a solution... Is there anything I can do about it? It seems super dangerous to be driving round with this possibility - it last happened when I was doing 60 round a country bend! Any help would be great, cheers.
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07-09-2019, 10:21 AM	#2
therealdb1 Lieutenant 106 Rep 576 Posts Drives: Graphite E93 335i Join Date: Aug 2017 Location: Norfolk UK iTrader: (0)	If there is a service bulletin and the mechanic knows about it surely he must know what is involved. Did you actually ask him what can be done rather than expecting him to tell you? If there is potentially a faulty valve in the servo line presumably this is the place to start. If your mechanic does not know what to do or is unable to help find someone else that is more knowledgable about BMW's and get them to take a look before you hit something / someone!
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07-11-2019, 08:59 AM	#3
NedPuckM Registered 0 Rep 2 Posts Drives: 3 Series - E91 Join Date: Mar 2019 Location: UK iTrader: (0)	That's what I thought, and we'd discussed it before so I assumed if there was a potential solution he'd have let me know... Either way I've messaged him and he's gonna get onto BMW to find out what can be done.
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