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2006 650i Black Sapphire Metallic
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Discussion Starter · #1 ·
For a while now my car has made "creaking" noises when I pull out of the garage and make a tight turn to go down the driveway. It seemed to go away when driving so I wrote it off a an issue of infrequent driving.

Now the problem seems consistent even after driving. No braking problems, no pulling to either side, no squeal or noises in normal driving. Just these creaking noises when starting after stopping with normal braking. Not so much with VERY gentle braking to a stip. Pedal isn't spongy but if held long enough will slowly sink to the floor if the car is running, i.e., with power booster active. (My Ford Escape does the same thing.)

I've pulled all the wheels, cleaned all the guide pins, cleaned and greased the caliper contact points. All the calipers retracted easily so I don't think any are frozen. All the pads have >6mm of material remaining.

I'm leaning towards the master cylinder but looking for any other thoughts before I jump into that.
 

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'07 650i e64
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Pedal isn't spongy but if held long enough will slowly sink to the floor if the car is running, i.e., with power booster active. (My Ford Escape does the same thing.)
If the pedal will go to the floor, then I think that brake fluid is leaking somewhere. If if doesn't require regular brake fluid refills, then I think you have an internal leak in the master cylinder.

To see if your brakes are sticking, park it on a smooth level surface, put it in neutral and see if you can make the car move by pushing it.
 

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2006 650i Black Sapphire Metallic
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Discussion Starter · #3 ·
That goes along with my thinking. There are no visible leaks and reservoir is still at correct level with no refills.

I'll give your push test a try. Thanks for the idea.
 

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make sure you dont have your foot on the brake when you are turning out of the driveway, that would also cause some noise. another option is air in the system. could just need to flush your brake fluid. a visual inspection of your brake calipers is needed to check for leaks among other areas. master cyl is last place I'd look, but that is just me, but its definitely and always a candidate to go bad. not certain on this, but you could also have a vacuum leak at the power booster, check the hoses. last thing, make sure you dont have a bunch of crud build up in your pads where they are suppossed to glide on the calipers and also make sure your dust caps are still on the calipers. if dirt gets in there, that is no good either.
 

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2006 650i Black Sapphire Metallic
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Discussion Starter · #5 ·
Thanks for the thoughts, Jim.

"I've pulled all the wheels, cleaned all the guide pins, cleaned and greased the caliper contact points. All the calipers retracted easily so I don't think any are frozen. All the pads have >6mm of material remaining."

Unstated was that the dust caps are there and I cleaned and inspected everything else while I was in there.

I understand a correlation between the pedal going to the floor on a booster leak but could a vacuum leak cause the "sticking" of the brakes? It does seem that they are stuck after normal braking. The car won't even creep forward after taking my foot off the brakes. It takes gas to get it moving.

Due to the tight configuration of my garage and driveway with walls on three sides, braking is required when pulling out to avoid hitting a wall. The problem exists even without any turns. A stop with normal braking will cause a "creak" from multiple wheels when starting up. This is preventing me from getting an inspection sticker as the station declared sticking as a brake system failure after it made the noises pulling straight into the inspection bay.

I will do a good bleeding. Not sure how air would have gotten in but it is cheap and east to try first.
 

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I will do a good bleeding. Not sure how air would have gotten in but it is cheap and east to try first.
Plus required maintenance every 2 years (or so) anyway.
 

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2006 650i Black Sapphire Metallic
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Discussion Starter · #7 ·
Plus required maintenance every 2 years (or so) anyway.
Thanks. Seems a bit aggressive timing compared to most vehicles but the dealers have to make money somewhere. :)

I just took over this car so I'm not sure of the last time it was done. Service menu shows it as OK so the time period isn't up yet and and the fluid in the reservoir is still the virgin color but worth doing to see if it resolves the problem.

I was also thinking that the slow fade of the pedal to the floor only occurs with the engine running and that is more likely to be the power booster rather than the cylinder itself. Does that seem logical?
 

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'07 650i e64
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I was also thinking that the slow fade of the pedal to the floor only occurs with the engine running and that is more likely to be the power booster rather than the cylinder itself. Does that seem logical?
I think that the brake booster can't allow the pedal to go to the floor unless there is some mechanical failure in the booster linkage (then it would go to the floor fast, not slowly). A ruptured diaphragm in the brake booster would leave you with "non power brakes", not a pedal that goes to the floor. I think that the reason the pedal goes to the floor only with the engine running is because the booster is doing it's job and putting extra force into the master cylinder causing higher pressure which then causes the master cylinder to leak internally.

I think that you have two problems, however, because I don't understand how a internal leak in the master cylinder would cause the brakes to stick.
 

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Thanks. Seems a bit aggressive timing compared to most vehicles but the dealers have to make money somewhere. :)
Maybe, I don't know. Good practice tho. I have a brake bleeder which lessens the pain. One reason these cars can go so many miles if these schedules are maintained
 

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2006 650i Black Sapphire Metallic
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Discussion Starter · #10 ·
I checked the service menu and the brake fluid change date was 7/2022. I changed it anyway but little improvement. Unless anyone has a better idea the master cylinder is next..
 

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Michael
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Have you tried being on a straight road zero traffic and doing some hard breaking, say 60-70mph to zero causing the anti lock to work overtime, this will stress everything and it just might clear the problem??? It may also cause the fault to harden hence easier to find???
I change my brake fluid every two years, easy to do and not expensive as I also have a pressurised fluid change system so no air in the system.
 

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Discussion Starter · #12 ·
No I hadn't tried that but certainly worth a try. I will need to wait until it stops raining here near Boston. Thanks for the suggestion.

I did the fluid change with my vacuum bleeder. I will say that the threads on the bleeder screws leak more air than any other car I've ever done. A pressure bleeder is definitely better on this car.
 

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No I hadn't tried that but certainly worth a try. I will need to wait until it stops raining here near Boston. Thanks for the suggestion.

I did the fluid change with my vacuum bleeder. I will say that the threads on the bleeder screws leak more air than any other car I've ever done. A pressure bleeder is definitely better on this car.
Well, that is a clue to something. maybe someone didn't bleed the brakes correctly last time back on 7/2022. Your fluid should have been clear if that was when it was done. and zero bubbles in it. do you mean 7/2021 ? still should not have bubbles.
 

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Discussion Starter · #14 ·
Sorry, I should have been more clear. The menu shows the next service date for changing the fluid as 07/2022. If the service interval is two years than it should only have been 1 year old.

The fluid looked good. With a vacuum bleeder it is possible to get bubbles due to air lead around the threads when the bleeder valve is open. On most cars I've done that is very minimal with the valve just open. On the BMW I can hear the air rushing in as soon as I crack the valve and there are continuous bubbles when open. To be sure I resorted to the old-school method and had my wife work the pedal for me.
 

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BMW TIS also calls for ABS activation during brake bleeding procedure. I've been educated that it is open anyway, so not 100% required. Maybe Herb will jump in and clarify. I listed my procedure down near the end. TIS is probably no longer active. If you plan on having this car for a while, the Motive bleeder is a fine piece of equipment.

 

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2006 650i Black Sapphire Metallic
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Discussion Starter · #16 ·
I'm quickly learning that nothing I knew about working on cars applies to BMW. I'm going to have to reference the TIS just to put gas in it. :)

It's unclear how long I will keep this car, although the power bleeder is a good general tool. My wife has declared a "one in, one out" rule on acquisitions since we're contemplating moving. Right now I have 4 cars and a motorcycle for the two of us. I'm running out of space and time to work on them and actually use them and if we move it will be tighter. With three "sunny day" play vehicles it's an toss up on what to use for a fun drive.

Good writeup on the brake bleeding. I've used ISTA to code a replacement CCC and have INPA but haven't used it yet. I'll have to see if I can actuate the ABS with that rather than pick up another device if that is required..
 

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Discussion Starter · #17 ·
The hard braking wasn't much help. At this point I think I'll do the master cylinder and that will require bleeding so between the two it should be resolved.

Thanks for everyone's help.
 

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Michael
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Pity the hard breaking did not bring anything up but is worth a try! hopefully it is the booster or master cylinder, just out of interest any oil in the vacuum line to the booster???
 

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Ya still there dig? How about you photo document your master cyl replacement for us?
 
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Discussion Starter · #20 · (Edited)
Still here. Got caught up in some client computer issues. Working gets in the way of all sorts of things. ::).

I hadn't looked at the vacuum line but I will when I get into it. I have the new master cylinder but still waiting for the new pressure bleeder to arrive before I start. Found a YouTube on using INPA to bleed the ABS/DSC on an E46 so I expect to be able to do that too as the E64 should be the same.

I'll see what I can do about documenting this process. I've done some for my Ford Escape ABS sensor and repairing the window crank mechanism on my 240Z. (Everyone remember what a window crank is??? :LOL:.) We'll see if I can add anything to the service procedure in the manual..
 
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