[humbucker87]

Made a costly mistake this week and wanted to warn others just in case they hit the same thing. It's hinted in a few other threads, but I'm hoping to make this post so it's more easily searchable.

So my plan was to change the pads and rotors on my wife's 2019 X5 and do a brake fluid flush at the same time.

The actual steps to replace the brakes are fairly straightforward and I don't think caused my issue. I'll list the steps below.

The problem was in bleeding the brakes. On every other car I've owned you can simply open the bleed valve at each caliper and pump the brakes to bleed fluid (either using the two man method or a bottle with a one-way bleed valve). However, upon pushing the brake pedal I heard some kind of pump actuating and then I noticed my bleed bottle filled up quickly. My first thought was "great that just made the process much faster".

However, upon starting the car I got all sorts of warning messages:
"Brake system malfunction: tow car to dealer"
"Chassis stablization disabled"
"Parking brake malfunction"

What could be wrong I thought. At least I can do a quick, careful drive around the block to assess things. Pedal was soft and something felt like it was stopping with about half the power it usually does. Tried to stomp on the brakes got a weird screeching noise, some ABS actuation and a much slower stop than desired.

Got the car home and realized two rotors still had my finger smudges on them (absolutely no brake actuation) and two of them had already resurfaced the rotors.

As mentioned in several other threads I found, this now required a complete ABS/ECU reset that could not be done with simple bimmerlink tools.
https://g05.bimmerpost.com/forums/sh....php?t=2050062
https://g05.bimmerpost.com/forums/sh....php?t=2100513

I took it to a local indy shop who wouldn't look at the car without first charging $140 diagnostics. I thought, "fair enough, then maybe it'll be another $100 or less to just reset the codes". They then called and said there could be air in my ABS and they'd need to bleed it for an additional $330. I really tried to fight them on this and call BS, but in the end they insisted. What was I going to do, pay another shop $140 for them to potentially tell me the same. So I caved. $500 later I have my car back in working order.

Why on earth are these things not more DIY serviceable! Owners of these cars in the future are doomed. They simply aren't serviceable unless you have expensive computer equipment. Even more worrying BMW made the decision that upon sensing loss in brake pressure (aka bleed procedure) that it would prevent any braking to those circuits without a computer reset. The engine wasn't on during this procedure, just door open and battery plugged in.

My advice to others is one of the following:
1) Trying to just gravity bleed without pressing the brake pedal.
2) Maybe you can disconnect the battery(ies) and bleed the old fashioned way, not sure.
3) Use ISTA or another tool to properly bleed them
4) Pay a shop



Since it may help others, here are my steps for pad/rotor replacement...

Front pads are straightforward:
1. knock the retaining clip out.
2. Undo the wire clips for the brake line and wear sensor
3. Undo the torx bolts holding in the caliper
4. Remove pads by prying out
5. Compress pistons
6. Remove rotor retaining screw
7. Smack rotor and remove
8. Installation in reverse order

Reverse pads a bit more complicated:
1. Undo two slide pin bolts (had to have a skinny 17mm open end wrench to hold the slide nuts
2. Remove caliper and then remove pads.
3. Undo the two torx bolts holding the caliper mount
4. Use bimmerlink or similar to put rear calipers in service mode so that the parking brake is retracted.
5. Only now compress the piston.
6. Remove the rotor retaining screw
7. Smack rotor and remove
8. Install in reverse order
9. Return pistons to non-service position using bimmerlink
9. I've seen some things say to engage the parking brake and release before first use (not 100% sure about this).

[rota92]

Sorry to hear about your flush/bleed woes. I did ours the other day with a Motive power bleeder and it was completed without any issue. Power bleeders are great to have on hand.

I do miss the days of the manual bleed with my dad going corner to corner cracking the bleeders while I pumped the pedal, though!

[humbucker87]

Originally Posted by rota92

Sorry to hear about your flush/bleed woes. I did ours the other day with a Motive power bleeder and it was completed without any issue. Power bleeders are great to have on hand.

I do miss the days of the manual bleed with my dad going corner to corner cracking the bleeders while I pumped the pedal, though!

Yeah thanks. That's a great point that pressure bleeding would work well here too. Anything where you don't actually touch the brake pedal

And yes, the good ole days are gone with respect to working on your own car I'd say

[Nick7700]

Originally Posted by rota92

Sorry to hear about your flush/bleed woes. I did ours the other day with a Motive power bleeder and it was completed without any issue. Power bleeders are great to have on hand.

I do miss the days of the manual bleed with my dad going corner to corner cracking the bleeders while I pumped the pedal, though!

I plan on doing mine sometime in the spring/ summer. Would you happen to have instructions on how to use the Motive power bleeder? Any diy or videos would be helpful. I just don’t want to screw up and turns out costly. Thanks!

[eelnoraa]

Thank you for sharing. I wil definitely take note when time comes for mine.

[rota92]

Originally Posted by Nick7700

I plan on doing mine sometime in the spring/ summer. Would you happen to have instructions on how to use the Motive power bleeder? Any diy or videos would be helpful. I just don’t want to screw up and turns out costly. Thanks!

Unfortunately I don't have any sort of reference. The power bleeder is really straightforward and honestly almost idiot proof.

You set it up with some pressure on the fluid reservoir, go about your bleeding procedure, checking pressure after each corner and/or inside/outside of the caliper, and try not to make a mess of the brake fluid.

I'm sure there are some vids out there. Definitely some on general power bleeder use!

One comment though - I enjoy doing some form of maintenance. For the money at my local indy shop, I'd suggest this procedure is well worth it. If it's under $300 out the door, it saves a lot of time. I put the car on 4 jackstands to get the car level, inspect brakes and rotate tires. That was literally half the time it took.