Brakes Dragging Right After Brake Job

[dannyzabolotny]

I finished replacing the brakes earlier last night on my 2000 540it— it started out as a pretty routine brake job. I replaced the worn out old pads and rotors with new Zimmerman rotors and Akebono pads. I also replaced both the front and rear pad sensors with new ones.

The problems started after the job was done— I put the car back on the ground, double-checked the torque on the wheels, and then went for a test drive. I immediately noticed that the car was struggling to move, so I figured the brakes were dragging. I opened my windows while driving slowly and I heard tons of grinding/screeching from the brakes. Needless to say, I didn't go very far and went right back home. The brake fluid level looks fine, and the brakes themselves seem to work fine when I press the brake pedal, albeit with a mushier feel. When I pressed the caliper pistons back into place with a C-clamp, I had the brake fluid reservoir cap open.

I've done plenty of brake jobs, including ones on the E39. I just did the brakes on my friend's 2002 540it a few weeks back and that had zero problems. So it's really weird how this time it's not turning out normally. The brakes worked fine before I did the job, they were just worn down with severely grooved rotors.

The mushy feel + the brakes dragging makes me think that somehow I may have introduced air into the system? I can't imagine how that could have happened given that I did nothing out of the ordinary during this brake job. I do know that this is affecting all of the wheels— I jacked the car up and tried to spin each wheel by hand, and all of them have a fair bit of resistance, so it's not isolated to just one wheel.

Any thoughts/advice would be much appreciated, thanks!

[HoZy]

Did you bleed the system properly? (In regards to your theory of air in the lines)

Or did you just push the pistons back in and call it good enough?

Cheers
Mat

[crazy4trains]

Next logical step is to bleed the system. System should be flushed anyway so just go ahead and do it.

[dannyzabolotny]

Did you bleed the system properly? (In regards to your theory of air in the lines)

Or did you just push the pistons back in and call it good enough?

Cheers
Mat

I have not bled the system yet, I just pushed the brake caliper pistons in with a C-clamp. I’ve done that for several other brake jobs without needing to bleed the brakes... I know that air in the system can cause a mushy pedal, but can it also be causing the brakes to drag?

[dwgates]

I wouldn't expect that air in the line would make anything drag. I had a similar problem the last time I did the pads on my 2001 540i though and ended up finding frozen calipers. I'm in the rust belt though so it comes with the territory. The brakes seemed fine and the caliper pins looked ok so my guess is the calipers just didn't respond well to being fully compressed so I could get the new pads in. You could try exercising the calipers by pressing them in and pushing them out with the pedal to see if something is just bound. Even though I don't think air in the line would cause binding or dragging but you might try bleeding just to see that you're getting fluid out when you press the pedal. I've had flex lines collapse inside due to age and they form a restriction that keeps pressure in the caliper and causes dragging. Brake fluid can collect moisture so you can have trouble like this even in drier climates. When I replaced my calipers I put new flex lines on because they're pretty cheap and it makes the caliper install easier (IMHO).

[JimLev]

Like Dwg said, air won't cause the brakes to stick.
Seeing that all 4 wheels are dragging it has to be something wrong with the master cylinder not allowing the all the fluid to return or possibly rusty pistons that won't return when the brake pedal is released.
Did you look behind the boots to see if the sides of the pistons were rusty? Hard to beleive all 4 of them could be bad, but you never know.

[dannyzabolotny]

Like Dwg said, air won't cause the brakes to stick.
Seeing that all 4 wheels are dragging it has to be something wrong with the master cylinder not allowing the all the fluid to return or possibly rusty pistons that won't return when the brake pedal is released.
Did you look behind the boots to see if the sides of the pistons were rusty? Hard to beleive all 4 of them could be bad, but you never know.

The pistons all looked fine to me, no signs of rust at all. This car has been in the Southwest forever so there’s zero rust on anything. The brakes also worked fine right before I did this brake job. Is there a way to test the master cylinder to see if it’s working properly?

One thing worth noting is that I saw a wet spot under the brake fluid reservoir after I put everything back together... I originally thought excess fluid came out of the reservoir when pressing the caliper pistons back in. My brakes were all super worn down, like to the point of where the BRAKE light was on, so I had to compress the caliper pistons a fair bit.

[HoZy]

The pistons all looked fine to me, no signs of rust at all. This car has been in the Southwest forever so there’s zero rust on anything. The brakes also worked fine right before I did this brake job. Is there a way to test the master cylinder to see if it’s working properly?

One thing worth noting is that I saw a wet spot under the brake fluid reservoir after I put everything back together... I originally thought excess fluid came out of the reservoir when pressing the caliper pistons back in. My brakes were all super worn down, like to the point of where the BRAKE light was on, so I had to compress the caliper pistons a fair bit.

Should've opened the bleed nipple to compress the pistons and not forced the pressure back into the Master, especially if the reservoir was already full.

Really don't know why people don't bleed brakes when it takes such little time.

Cheers
Mat

[dannyzabolotny]

Should've opened the bleed nipple to compress the pistons and not forced the pressure back into the Master, especially if the reservoir was already full.

Really don't know why people don't bleed brakes when it takes such little time.

Cheers
Mat

Because bleeding brakes is a two person job and I have nobody to help because I do my wrenching at like 2am. I know there are pressure bleeders that eliminate the need for a second person but I don’t have one of those laying around at the moment.

[HoZy]

Because bleeding brakes is a two person job and I have nobody to help because I do my wrenching at like 2am. I know there are pressure bleeders that eliminate the need for a second person but I don’t have one of those laying around at the moment.

Put a tube from the nipple into a jar/container with fluid at the bottom, pump the peddle until hard, Undo the nipple and go pump the peddle a bunch, Once there is fluid in the line & in the jar it can't suck air back up. It's the same way a single person bleeder works that you can buy at an autoparts store for $10

Been bleeding my brakes by myself for 6years on the E39 with no issue, and that's been done 3times. Let alone the E46 & E83 and the other cars I've owned over the years.

Cheers
Mat

[dannyzabolotny]

I'm going to troubleshoot the problem with a friend tonight. We'll try to bleed the brakes first to see if that helps at all.

[adm750]

DannyZ !! Sorry you are struggling with this. Nothing like having a routing job start to go backwards on you. Like HoZy said....tube-in-a-jar method is tried and true for bleeding. You're savvy enough from what I've read of your posts that you'll have that addressed asap.
I have been known to just pull the cap and let the fluid flow back to the reservoir too (as I might be on a time constraint to bleed while replacing pads...) but there may be a very legit reason there is a downside to doing that. If pads are low and the reservoir is full that certainly could explain the small loss you see below the car but you said the warning light was on so I assume fluid level was at the low point. We all know that brake fluid is the ONLY fluid you DO NOT want to top off unless immediately after brake pads have been refreshed or some other repair created an actual fluid loss.

dwgates made a good point ! when those pistons are extended that far, they sure don't like to act right at times after being compressed. There can be some buildup on the formerly extended portion of those pistons that can now be binding in the caliper bore. Plus, they do like to pitch themselves at odd angles inside the bore upon use after those hyper-extensions...

Now to the sticking part....it's back to the basics:

- ensure all pad contact points are not binding. odd that it would be all four wheels but even with hi-quality aftermarket parts, that is something we all must watch out for. (odd tolerances, extra backing plate paint/coating making things stick a bit, etc..)
- ensure caliper guide pins are lubed and moving "freely" within their bushings. Like one of my posts the other day - I pull and lube these 2x per year during wheel swaps because of what I have seen in the past...

Now - if all that appears in order, I'm re-tracing my steps since everything was essentially "good" before (besides overextended pistons from severely worn pads...)

- did a caliper get flipped prior to reinstall, thus kinking the brake line hose ?
- are you absolutely certain that the pads are correct for the application ?

Do we go outside the box next ??

- how do the brake lines look ? are they stock ? Maybe bleed a corner and see if you are getting any black material (debris or black-ish slurry) in the brake fluid. I have seen where these rubber brake lines start to deteriorate internally and cause calipers to bind since the fluid cannot go back in the circuit relieving pressure from the piston(s). This was on, say, 99-01 era cars and I've been out of the biz for over 5 years now...so this was happening in vehicles that were not that old surprisingly..!!
- did a metal line somehow get pinched during the job closing off a portion of the circuit ? (this may also explain the small fluid loss from the system as there could be a pinch and a resultant small crack in a line now...)

I know I'm missing a bunch of ideas here, but I'm stuffing pizza down, and trying to type, while on my lunch hour...lol...

Good luck, please let us know what you find....
tony

[wagons ho]

Rumor has it that front rotor backspacing changed in 01. Did you put the wrong rotors on your 99?

[dannyzabolotny]

I ordered all of the parts from FCP Euro, keeping in mind the changes between production years. I've never really had an issue with buying brake parts from there before.

These are the rotors I got for the front: https://www.fcpeuro.com/products/bmw...rt-34111165859

These are the rotors I got for the rear: https://www.fcpeuro.com/products/bmw...rt-34216767060

The pads are Akebono. I lubricated the appropriate parts when assembling everything.

Unlike most other threads I've read on this issue, mine isn't an occasional dragging. It literally feels like the brakes are 30-40% applied at all times. When I put the car in drive or reverse, it doesn't move at all. I need to use a considerable amount of throttle to get it moving, and it makes terrible noises.

I don't have any error lights on at the moment, but is there a chance my ABS/traction system is the cause of this?

[StephenVA]

Danny,

Try this trick, Crack open the breeder screw, compress one caliper at a time and close. Pump pedal, replace lost fluid, test calipers to see if they release.

As mentioned some calipers just lock up when you compress them all the way due to rust, dirt in the cavity, etc. Depending on hot they got there is junk that gets pushed way back up in the lines. Some ABS units then see the issue and slide over to lock down each line.

Question: If you bleed them individually, do they actually pump out fluid? If not then you know what that means, abs activation time to get them unlocked. Multiple strokes and multiple cycles before they will clear completely.

Good luck...Let us know the outcome.

Sorry your the "lucky one".

[crazy4trains]

Zimmerman's coating takes a little while to wear off and sounds horrible the first few stops. If you only drove a block or two it could be as simple as driving a little further to ensure all the Z-coat wears off. Crossyerfingers.

[dannyzabolotny]

Zimmerman's coating takes a little while to wear off and sounds horrible the first few stops. If you only drove a block or two it could be as simple as driving a little further to ensure all the Z-coat wears off. Crossyerfingers.

I feel like it's a bit more than just that. The pedal doesn't feel right either. I'm gonna bleed all 4 corners and see if that fixes anything. I'm going to be doing it with a friend who's been wrenching for 30+ years, so I'm confident we can figure out.

The funny thing is that I'm supposed to be driving the touring to San Francisco tomorrow morning. I guess if the brake issue doesn't get resolved today, I'll be forced to drive the Corvette. It's not the worst fate ever but I really wanted to drive the touring, it's a lot more comfortable for road trips.

[fullthrottle540]

Should've opened the bleed nipple to compress the pistons and not forced the pressure back into the Master, especially if the reservoir was already full.

Really don't know why people don't bleed brakes when it takes such little time.

There is no need to bleed brakes for a pad & rotor replacement. I've always compressed the piston with a towel under the brake reservoir, never had a problem.

I think brakes dragging have to be a caliper or fitment issue, shouldn't have anything to do with air in the lines if you ask me

[dannyzabolotny]

There is no need to bleed brakes for a pad & rotor replacement. I've always compressed the piston with a towel under the brake reservoir, never had a problem.

I think brakes dragging have to be a caliper or fitment issue, shouldn't have anything to do with air in the lines if you ask me

The brake pedal feels pretty soft, that's the other issue.

The only other thing I can think of is that when I did the brake job, I removed the calipers by undoing the 18mm caliper bracket bolts in the front and the 16mm caliper bracket bolts in the rear. I didn't bother with the 7mm allen bolts on the calipers like in most DIY's, reasoning that it's a lot easier to just remove 2 bolts instead of 4, since the rotors had to be replaced anyways.

[auaq]

Try clean up and regrease the sliding pins.

[crazy4trains]

IIRC the caliper bolts/pins, if they are the original style that slide into the rubber bushings, are not supposed to be greased.

Good luck. I was hoping you were just hearing the z-coat wearing off but if you have a change in pedal feel that's definitely not coating related.

[HoZy]

There is no need to bleed brakes for a pad & rotor replacement. I've always compressed the piston with a towel under the brake reservoir, never had a problem.

I think brakes dragging have to be a caliper or fitment issue, shouldn't have anything to do with air in the lines if you ask me

Brake fluid should be done every 2years, if you're due to replace pads & rotors you are well and truly due to bleed the brakes.

It costs under $20 and takes less than 15minutes if the wheels are already off, stupid not to.

It's like people are scared of brake bleeding or think they need to buy $100+ power bleeders and all this other junk.

Hell a $15 eBay vacuum hand pump bleeder will do it as well.

Cheers
Mat

[bdiefAZ]

I have a bleeder and live just north of Phoenix - shoot me a PM

[rjbaren]

It sounds like the wrongs parts could causing the pads to touch the rotors and cause drag but I'm sure you would have noticed that when installing. There are also two little rubber brake hoses in the drivers side wheel well behind a cover. If one of those were to swell internally they could apply some braking pressure or at least not let the brakes release. They are pretty inexpensive and it's not a bad idea to consider replacing them on cars as old as ours. If it's one corner, it could be a caliper brake hose. 1 axel, then it could be the little hoses in the wheel well. All four wheels, then it sounds master cylinder relayed. Just guessing, good luck.

[dannyzabolotny]

Good news! I figured out the issue with my friend

Turns out the new rotor was rubbing the caliper bracket really badly...



Not sure if the rotor is the wrong part or something, but it looks like the backspacing on it is off so it rubbed the caliper bracket on one side and had tons of room on the other side.



My solution was to reinstall the old brake rotors. The front wheels spin properly and the back wheels turned out to be fine all along, so everything seems to be good now.

Once I get back from my road trip I’ll contact FCP Euro and find out what’s up with these wrong front rotors...