Brake pedal constantly going soft
Quote:
Originally Posted by Valdelisbmw
Quote:
Originally Posted by Dave
Ok, this might be completely unrelated.
Does this car have any kind of brake bias controller?
I know this is chalk and cheese, but I had an old MK2 golf gti do exactly the same thing.
There's a valve on the rear swing arm that actuated a valve depending on the attitude of the car.
So unless you actuated the brake bias controller when you were bleeding the brakes, you created an air pocket when you were trying to bleed them.
At least the issue is developing.
It's called brake load valve ,for old as my life cars with non independent suspension
I know what the valve is and while it is in no way physically related to the system that exists on the M6 it must surely be possible for the modern equivalent of that system to go wrong and incorrectly bias brake pressure to the rear.
In just throwing out an idea. Might be pointless.
RE: Brake pedal constantly going soft
Quote:
Originally Posted by Dave
Quote:
Originally Posted by Valdelisbmw
Quote:
Originally Posted by Dave
Ok, this might be completely unrelated.
Does this car have any kind of brake bias controller?
I know this is chalk and cheese, but I had an old MK2 golf gti do exactly the same thing.
There's a valve on the rear swing arm that actuated a valve depending on the attitude of the car.
So unless you actuated the brake bias controller when you were bleeding the brakes, you created an air pocket when you were trying to bleed them.
At least the issue is developing.
It's called brake load valve ,for old as my life cars with non independent suspension
I know what the valve is and while it is in no way physically related to the system that exists on the M6 it must surely be possible for the modern equivalent of that system to go wrong and incorrectly bias brake pressure to the rear.
In just throwing out an idea. Might be pointless.
ABS ASC DSC now does the lot
Brake pedal constantly going soft
Hi Mark,
Does the pedal go to the floor with the car turned off?
Was a pressure bleeder used to bleed the brakes? Or were they bled manually?
Was the ABS unit bleed procedure done?
Has the car recently had new pads etc fitted?
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RE: Brake pedal constantly going soft
No new pads fitted recently.
As mentioned all work is being done by BMW under their warranty so the brake bleed procedure is to use their machine which is both a pressure bleeder & hooks up to ISTA for ABS unit bleeding.
With the car off the pedal does not travel to the floor, also when driving the pedal doesn't travel as much as it does when stationary or driving at very low (eg car park manoeuvring speeds), the travel is much more pronounced.
I am wondering if the rear brakes binding is a new separate issue to clamping the rear flexible hoses (using proper hose tool), done to rule out dodgy callipers? The hoses look fine but maybe damaged internally?
Looks like I'll be saying goodbye to it for another few weeks as it goes in for diagnosis, maybe even for good. Getting fed up with it.
RE: Brake pedal constantly going soft
Don't give up on it yet Mark. When this is all done, you'll have a pretty well sorted M6 that you'll be able to enjoy finally! It's also possible that the new vaccum pump/ master cylinder is faulty too so wouldn't rule that out either!
RE: Brake pedal constantly going soft
I'd agree with the above Mark, try to keep the faith. I'd be looking for some good will from BMW though, they should be offering a free service or something as compensation for all the hassle you've had so far.
Even if you add up the time it's spent in the garage, it cost's €150 a month to keep your car taxed, so you've wasted at least that through not having the use of the car for weeks on end!
Hopefully it all gets sorted for you, once and for all!
RE: Brake pedal constantly going soft
Well, car has been dropped off again this morning to the dealers, God knows when I'll get it back this time.
It seemed to manifest itself every two weeks but it could also have been once I have done around 500kms of driving.
You can imagine the one word I'm thinking of:
RE: Brake pedal constantly going soft
New DSC module fitted yesterday. But has to stay for another week to get a new fuel tank! :eek
RE: Brake pedal constantly going soft
Do they give you a courtesy car mark? Ask for something of a similar calibre- like an extended m4 test drive :)
RE: Brake pedal constantly going soft
^ what he said!!! And call me when you get it :p