NIGHTMARE BREAK JOB warning, long post lots of detail

[warbird026]

Hello everyone,

I have entered what appears to be a nightmare of a break job on my X5. She's an 01 4.4 with the sport package. It is not the first one that I have done on this vehicle, but since she has some miles now I figured I would replace a few more things. There were no problems before starting the work other than the brakes were just worn and it was time to replace them.

When I started it was just going to be pads, rotors, lines and I was going to rebuild the calipers while I was at it. Once torn down the calipers looked pretty rough so I decided to just replace them too. So, had everything torn down and started going back together when I discovered a line would not thread properly into one of the front calipers. The first 3 threads were folded and not a single one of my die's would match. Called ECS and they took care of me. It was about a week or so that the X sat on my lift waiting for parts. My main mistake was leaving my brake lines all open and the reservoir was able to empty out (I know, dumb) but I have a buddy with DIS and he said it wouldn’t be an issue to burp everything (famous last words).

So, got everything back together; new lines, calipers, rotors, pads, fresh fluid and started bleeding. I knew it would take a bit so I was patient. We bled the traditional way with engine off and the pedal started feeling good after several trips around the vehicle. Once comfortable I had plenty of air out and was getting clean fluid I fired up the vehicle. Spongy/soft brake pedal. Pedal goes to about 3 inches off the floor and at that point starts to get hard. I figured that meant I had massive air pockets so I called up my buddy and he brought over his laptop. Hooked it up, I applied around 12-15 psi of constant pressure on the brake system with my air compressor, bled DSC numerous times and got some more air out, but was primarily from the rear calipers…the fronts were all clean fluid. That had me feeling good. After several rounds of DSC bleeding, fired up the car and nothing. Same thing. Brake pedal soft all the way down to about 3 inches off the floor. No amount of pumping changes it.

Now I’m thinking that maybe the master cylinder decided to bite it. So, I put a new master cylinder in it (bench bled before install) and while in there paid attention to the booster and it was clean…no fluid in it either in the bay or cabin (as a reminder everything worked just fine before the brake job). Rinse and repeat bleed steps. Ran the DSC bleed schedule several times until I was happy with the lack of air coming out of the lines. Started car and once again it flew the finger and kicked me in the jimmy….still no brake pedal. Now I’m really getting perplexed. I started looking over vacuum system and started wondering. So I decided to go ahead and replace the sucking jet pump since it’s easy and that took no time. I friend of mine that works at the local Bimmer stealership told me that even though everything and everyone states to use GT1 or whatever to activate the DSC he said that even still he ends up taking cars out and activating the ABS/DSC on the road. They actually have a stretch of road to do that. So, taking his advice I started the X up after replacing the jet pump and headed down the road. I made it a mile from my house, hadn’t even started attempting to get the ABS to activate when all of a sudden I get the three amigos…DSC/Traction control light, ABS, and Brake light…all amber. So, knowing the ABS won’t function under this scenario I pulled over and shut the car off, sat for a couple of seconds, then started it back up and took off. Got to activate the ABS once and that was it. Three amigos keep dancing on my dash.

What am I missing? Everything worked perfectly fine before the brake job. I know I introduced a lot of air in the system. Even that in mind, the MC is new and the booster does not “appear” to have any wear signs and was fine before this. Did it really just decide to break while sitting there for a week or two? I feel like I have shot gunned parts at it right now and HATE doing that. If it is an issue of massive amounts of air in the system, should I crack a line at the ABS/DSC and bleed some air directly from there? I am working on getting my buddy and his laptop back over later this weekend to look at codes. Should he look for something in particular? He is an E46 junkie and really doesn’t know much about X5’s.

So, quick recap;

Brakes worn, need changing, but had no problems to speak of.
Changed lines, calipers, rotors, pads.
Bled traditional way with engine off.
Soft/spongy pedal
Bled with DIS v57.
Still soft/spongy pedal
Replaced master cylinder
Blead with DSC
Still soft/spongy pedal
Replaced sucking jet pump
Went to drive and activate ABS
Three amigos now plus soft/spongy brake pedal

I’m sorry this is so long and winded, but I wanted to give as much detail as possible. I have read several different variants of soft brake pedal, but nothing with solid statements of what was done and not bullet points as to “sounds like this is the issue”. I know these systems are intricate, but this isn’t exactly rocket science either. I know there are still a couple of pieces to the system I have not touched yet, but I am still having a hard time wrapping my mind around the possibility of it “just broke” while sitting there on the lift.

I am still researching across the forums and in the next couple of days will have my own machine running the GT1 suite so maybe I can utilize the TIS for info, but for now I am really leaning on you guys. Please, I’m literally about to pull the hair out of my head and at this age in life I’m afraid that it will stop growing back at any minute!

Thank you guys for any and all advice!!

[deepblonde]

Originally Posted by warbird026

Hello everyone,

I have entered what appears to be a nightmare of a break job on my X5. She's an 01 4.4 with the sport package. It is not the first one that I have done on this vehicle, but since she has some miles now I figured I would replace a few more things. There were no problems before starting the work other than the brakes were just worn

Now I’m thinking that maybe the master cylinder decided to bite it. So, I put a new master cylinder in it (bench bled before install) and while in there paid attention to the booster and it was clean…no fluid in it either in the bay or cabin (as a reminder everything worked just fine before the brake job). Rinse and repeat bleed steps. Ran the DSC bleed schedule several times until I was happy with the lack of air coming out of the lines. Started car and once again it flew the finger and kicked me in the jimmy….still no brake pedal.

I am still researching across the forums and in the next couple of days will have my own machine running the GT1 suite so maybe I can utilize the TIS for info, but for now I am really leaning on you guys. Please, I’m literally about to pull the hair out of my head and at this age in life I’m afraid that it will stop growing back at any minute!

Thank you guys for any and all advice!!

There is probably just air still caught.
I would get a long length of clear tube and go from each bleeder in turn, with the tube going back to the master cylinder. Then open up the bleeder, and pump continuously watching the fluid until there are no bubbles.
You can do it endlessly without having to worry about running out of fluid, and you’ve got all new fluid and most of the components ( except abs) so isn’t much a risk of contamination.
Eventually you’ll get the air out.
It’s possible when you left it open for so long air got into abs or other hard to reach places, but doing it a loop will get it out eventually

[warbird026]

I appreciate the info.
As much as it pains me to say it, I'm pretty sure this is my fault (okay, like 99.9% sure), but I didn't realize it would be this much of a PITA
After reading a 6 page thread here I was starting to lean towards it literally just having that much air in it. However, i did see one thing that raised my eyebrow...could the ABS pump (or whatever pump) have run so out of fluid that it has just become one giant air pocket? Every time I bleed the system it has been with 12-15 psi of pressure, but at this point I question everything.

Thank you again for the input!!

[white46]

Have you tried reverse bleeding? It's pushing brake fluid from bleed nipple at caliper.
I once had trouble bleeding e46 clutch master cylinder and had to do reverse bleed.

[warbird026]

Originally Posted by white46

Have you tried reverse bleeding? It's pushing brake fluid from bleed nipple at caliper.
I once had trouble bleeding e46 clutch master cylinder and had to do reverse bleed.

I have not even thought of that...I'll have to look into that!

Thanks!

Sent from my ONEPLUS A5000 using Tapatalk

[andrewwynn]

I'm betting the answer lies in this line from the shop manual:

10. Activate precharging pump with DIS tester.
11. Bleed front axle circuit (also answering the question of was I correct (yes) the brakes are paired by axle)

If you have precharging pump there is air in that system needs to be purged.

[warbird026]

Originally Posted by andrewwynn

I'm betting the answer lies in this line from the shop manual:

10. Activate precharging pump with DIS tester.
11. Bleed front axle circuit (also answering the question of was I correct (yes) the brakes are paired by axle)

If you have precharging pump there is air in that system needs to be purged.

I did precharge the pump (test schedule), but I have not looked into a bleed on the front axle circuit singularly. I will definitely look at that. I'm spending some time on it tomorrow.

Thank you for the input!

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[andrewwynn]

Originally Posted by warbird026

I did precharge the pump (test schedule), but I have not looked into a bleed on the front axle circuit singularly. I will definitely look at that. I'm spending some time on it tomorrow.

Thank you for the input!

Sent from my ONEPLUS A5000 using Tapatalk

I think they're saying that you have to actually be running the fee charge while you're bleeding. Not like activated once to precharge but have the pump running.

[warbird026]

That's something we definitely did not do. We initiated the precharge pump schedule, but there were no open bleeder valves... everything was still closed up. I'm about to start working on it again now that I have a machine with DIS again. First thing I'll probably do is precharge with a bleeder open. Lol right now I'm thinking "What's the worst that could happen or go wrong at this point!?"

Thanks again!

Originally Posted by andrewwynn

I think they're saying that you have to actually be running the fee charge while you're bleeding. Not like activated once to precharge but have the pump running.

Sent from my ONEPLUS A5000 using Tapatalk

[wpoll]

Originally Posted by andrewwynn

I'm betting the answer lies in this line from the shop manual:

10. Activate precharging pump with DIS tester.
11. Bleed front axle circuit (also answering the question of was I correct (yes) the brakes are paired by axle)

If you have precharging pump there is air in that system needs to be purged.

Ultimately, since the ABS can control each wheel independently, there are at least four circuits...

But yeah, it sounds like the circuits are paired as axles... I guess the "rules" go out the door once you introduce ABS/DSC/DBC/TCS etc. into the equation...

Oh, and P.S. - the IS a fluid pressure sensor, in the master cylinder. It's used for the DBC....