Brake upgrade gone wrong lol

[aswy6]

Hey everyone,
Another day and another struggle with my M3. I was due for a brake fluid change so i though why not to upgrade to SS lines. So far this was the dirtiest job i have ever done. It was very slippery in there so i took my sweet time to get the lines back on. I think at some point the brake fluid level went below Minimum and i topped it off. I think i introduced air into the system because the pedal feels softer than before. Is there a way to know if i im braking with air instead of fluid? And what to do in this case? Bleed it again?
I am also changing my brakes soon because i want to attend a HPDE in fall so i was thinking to bleed them again. Any thoughts?

[ayao]

Rebleed.

[Hagasan41]

Pick one of these up and it will make brake bleeding so much easier. You can save a few bucks and get the other one that has a plastic adapter and no swivel. But this is the one I use and recommend.

https://www.amazon.com/Motive-Produc.../dp/B000Q6SL2W

[aswy6]

Originally Posted by Hagasan41

Pick one of these up and it will make brake bleeding so much easier. You can save a few bucks and get the other one that has a plastic adapter and no swivel. But this is the one I use and recommend.

https://www.amazon.com/Motive-Produc.../dp/B000Q6SL2W

I used Shwaben pressure bleeder which is close enough

[Pig Farmer]

If you pushed air into the lines by mistake, there’s a chance you have air trapped in the ABS system. I’ve heard there is a way to actuate the ABS pump to remove the air. I don’t know if it’s possible with Carley or some other software, but I have experienced the soft pedal after changing the brake lines. What worked for me was to go out and activate the ABS by trying to lock up the brakes. Then you need to do the two man brake bleeding process with the engine running. This is the only way I have been able to get a rock solid brake pedal.

BTW, did you replace the mid/rear lines? That was probably my least favorite DIY ever.

[aswy6]

Originally Posted by Pig Farmer

If you pushed air into the lines by mistake, there’s a chance you have air trapped in the ABS system. I’ve heard there is a way to actuate the ABS pump to remove the air. I don’t know if it’s possible with Carley or some other software, but I have experienced the soft pedal after changing the brake lines. What worked for me was to go out and activate the ABS by trying to lock up the brakes. Then you need to do the two man brake bleeding process with the engine running. This is the only way I have been able to get a rock solid brake pedal.

BTW, did you replace the mid/rear lines? That was probably my least favorite DIY ever.

Thanks, will try to lock the wheels next time it rains. I did not change the mid lines. I looked at them, poked my wrench around and decided that i am going to pay someone to do it lol. Potentially when upgrading to solid subframe bushings

[ayao]

Originally Posted by Pig Farmer

If you pushed air into the lines by mistake, there’s a chance you have air trapped in the ABS system. I’ve heard there is a way to actuate the ABS pump to remove the air. I don’t know if it’s possible with Carley or some other software, but I have experienced the soft pedal after changing the brake lines. What worked for me was to go out and activate the ABS by trying to lock up the brakes. Then you need to do the two man brake bleeding process with the engine running. This is the only way I have been able to get a rock solid brake pedal.

BTW, did you replace the mid/rear lines? That was probably my least favorite DIY ever.

This thread gives some details on ABS pump activation via INPA (which is way above my pay grade.)
I've pushed air into the clutch lines using a Motive pressure bleeder with air only (it was annoying) and there's nothing quite like the horror of seeing air bubbles spew out of the MT hydraulic bleed nipple when you're on your back underneath the car.
If you end up doing that just keep in mind that the clutch hydraulic lines gets fluid from the brake fluid master cylinder reservoir, but the fluid is drawn from a location that is relatively high in the reservoir.

In any event, it's probably worth rebleeding with a large quantity of cheap DOT4, getting a hard pedal back, and then redoing again with your actual brake fluid of choice. Good luck!

[ebisu8]

Originally Posted by Pig Farmer

BTW, did you replace the mid/rear lines? That was probably my least favorite DIY ever.

This.

[aswy6]

Originally Posted by Pig Farmer

If you pushed air into the lines by mistake, there’s a chance you have air trapped in the ABS system. I’ve heard there is a way to actuate the ABS pump to remove the air. I don’t know if it’s possible with Carley or some other software, but I have experienced the soft pedal after changing the brake lines. What worked for me was to go out and activate the ABS by trying to lock up the brakes. Then you need to do the two man brake bleeding process with the engine running. This is the only way I have been able to get a rock solid brake pedal.

BTW, did you replace the mid/rear lines? That was probably my least favorite DIY ever.

Do i have to lock up the brakes and then immediately bleed the brakes? Or can i lock activate the ABS today and then bleed it in the weekend?

[SpartaEvolution]

Originally Posted by aswy6

Do i have to lock up the brakes and then immediately bleed the brakes? Or can i lock activate the ABS today and then bleed it in the weekend?

Once you activate the ABS it will re-introduce the air back into the lines, so you'll want to re-bleed ASAP.

You can engage ABS fairly easily by braking heavily and turning at the same time. Obviously make sure you're in a safe spot to do so.

[SYT_Shadow]

Personally I don't like pressure bleeders, I feel they are asking to spray brake fluid all over nice paint


OP, hindsight is 20/20 but here's a suggestion: use a piece of wood to press the brake pedal all the way down. This blocks the reservoir from emptying from an open line or leak

[inTgr8r]

Originally Posted by SYT_Shadow

Personally I don't like pressure bleeders, I feel they are asking to spray brake fluid all over nice paint


OP, hindsight is 20/20 but here's a suggestion: use a piece of wood to press the brake pedal all the way down. This blocks the reservoir from emptying from an open line or leak

^this
if you look it up in TIS the brake pedal should be pressed down when opening a line.

I feel the same about pressure bleeders but after many years caved in and bought one.
....only because my helper retired from the job.

I use it to pressurize the reservoir, I don't feed fluid through it.

[deansbimmer]

Yes you're supposed to keep the pedal down when opening a brake pipe. It keeps air from entering the hydraulic system as the reservoir drains, not to mention keeps fluid from draining all over you while you change hoses.

There are portions of the ABS module in the valve block that can't be bled during a typical brake bleed and must be done via software with the bleed screws open (one caliper at a time) and a pressure bleeder on the reservoir. I don't know of any other way to do it. Activating the ABS during driving won't get the air out of all four channels. The software (ISTA-D) pulses the appropriate brake channel ABS solenoid while the bleeder is open and pushes aerated fluid out the bleed screw. The pressure bleeder pushes fresh fluid through during the whole process. This is repeated for each caliper/channel.

Pressure bleeders are the right way to do it. When used properly there's no risk of "explosions" or paint damage. Not only are they a real time saver, they make sure the job is done air free and with no mess. Its the way things are done at BMW and independent shops alike.

[aswy6]

Originally Posted by deansbimmer

Yes you're supposed to keep the pedal down when opening a brake pipe. It keeps air from entering the hydraulic system as the reservoir drains, not to mention keeps fluid from draining all over you while you change hoses.

There are portions of the ABS module in the valve block that can't be bled during a typical brake bleed and must be done via software with the bleed screws open (one caliper at a time) and a pressure bleeder on the reservoir. I don't know of any other way to do it. Activating the ABS during driving won't get the air out of all four channels. The software (ISTA-D) pulses the appropriate brake channel ABS solenoid while the bleeder is open and pushes aerated fluid out the bleed screw. The pressure bleeder pushes fresh fluid through during the whole process. This is repeated for each caliper/channel.

Pressure bleeders are the right way to do it. When used properly there's no risk of "explosions" or paint damage. Not only are they a real time saver, they make sure the job is done air free and with no mess. Its the way things are done at BMW and independent shops alike.

Thank you for the response. So,do you think its a better idea to use the pressure bleeder again? Should i just take it to the shop and tell them to use software and pressure bleeder like you described? And then for following changes, use the pressure bleeder?

[BayE30]

Originally Posted by deansbimmer

Yes you're supposed to keep the pedal down when opening a brake pipe. It keeps air from entering the hydraulic system as the reservoir drains, not to mention keeps fluid from draining all over you while you change hoses.

There are portions of the ABS module in the valve block that can't be bled during a typical brake bleed and must be done via software with the bleed screws open (one caliper at a time) and a pressure bleeder on the reservoir. I don't know of any other way to do it. Activating the ABS during driving won't get the air out of all four channels. The software (ISTA-D) pulses the appropriate brake channel ABS solenoid while the bleeder is open and pushes aerated fluid out the bleed screw. The pressure bleeder pushes fresh fluid through during the whole process. This is repeated for each caliper/channel.

Pressure bleeders are the right way to do it. When used properly there's no risk of "explosions" or paint damage. Not only are they a real time saver, they make sure the job is done air free and with no mess. Its the way things are done at BMW and independent shops alike.

for some reason i always had better luck with vaccum bleeders VS pressure bleeders...

[deansbimmer]

Originally Posted by aswy6

Thank you for the response. So,do you think its a better idea to use the pressure bleeder again? Should i just take it to the shop and tell them to use software and pressure bleeder like you described? And then for following changes, use the pressure bleeder?

For a correct bleeding procedure in these M3's, the pressure bleeder is used in conjunction with ISTA-D software to fully flush the entire system including the internal ABS hydraulics. This is a "one-stop" service and should also include reset of the condition based service interval. We charge $150 for this service here. Any properly equipped BMW shop can do this service but you need to make sure the do the flush with ABS activation. Lots of lazy shops say they do but don't and there's no way for you to check their work.

Quick lube type brake flushes only flush the main circuits and omit the critical ABS circuits. On just about every brake flush I've ever done, the fluid that comes out of the ABS pump is highly aerated and much darker than the other fluid. It's obvious that the techs doing the flushes only did half the job.

That aerated fluid greatly hampers proper ABS function and becomes a safety issue when you need the ABS to keep you out of trouble but it's full of air.

[aswy6]

Originally Posted by deansbimmer

For a correct bleeding procedure in these M3's, the pressure bleeder is used in conjunction with ISTA-D software to fully flush the entire system including the internal ABS hydraulics. This is a "one-stop" service and should also include reset of the condition based service interval. We charge $150 for this service here. Any properly equipped BMW shop can do this service but you need to make sure the do the flush with ABS activation. Lots of lazy shops say they do but don't and there's no way for you to check their work.

Quick lube type brake flushes only flush the main circuits and omit the critical ABS circuits. On just about every brake flush I've ever done, the fluid that comes out of the ABS pump is highly aerated and much darker than the other fluid. It's obvious that the techs doing the flushes only did half the job.

That aerated fluid greatly hampers proper ABS function and becomes a safety issue when you need the ABS to keep you out of trouble but it's full of air.

Well, i guess i will be getting that service next time im in Dallas. What would you suggest for a stop gap type of thing for now to get the pedal hard again before i am able to see you? Just bleed it using pedal bleeding or pressure bleeding? Activate the ABS or just keep the air in there? (Assume i dont use ABS in the near future)

[deansbimmer]

Pedal bleeding is a PITA and requires two people. Pressure bleed it starting at the farthest caliper going to the closest. Again, there's nothing you can do about the air in the ABS without software to activate each channel individually while the bleed screw is open.