Air in brake system (still) - rant/advice needed

[bimmerfiver]

I replaced my brake booster in January (it was filled with water/ice).
This resolved the immediate issue (frozen pedal in winter).
I re-used my original master cylinder (which was sitting in water on the booster-side).
I couldn't afford a master cylinder at the time.
I was left with a spongy brake pedal after this repair in January.
I bleed my brakes about six times using oldschool method (push on brake pedal, force fluid out at caliper nipple).
I couldn't get the brake pedal to firm up no matter what...the pedal is spongy and travels a few inches before brakes grab/engage.
I attributed a fubar Master Cylinder as the culprit.
Today I replaced the Master Cylinder and resovoir.
I bench-bleed the Master Cylinder.
I bleed the brakes (old-school method).
My brakes are still soft/spongy.
I still have air in the system.
You don't have to ask about pads/rotors/calipers...they are all A+.

Rant over. Facts laid out.

I am an inch away from having to go to the dealership to have them bleed, where they electronically engage the ABS to force ALL air out of system. Or I am prepared to buy a cheesy Reverse-Bleed Kit like this one:

http://www.brakebleeder.com/powerblock.html


My OTHER tin-foil hat suspicion is...DOES one have to and CAN ONE adjust brake pedal TRAVEL in the e39? MANY cars have adjustment on brake pedal inside the car, at the pedal, where it connects to the BOOSTER. Our booster rods have no obvious adjustment...being that I replaced my booster and master cylinder, I am scractching my scalp wondering if simply turning the Brake Booster's rod somehow adjusts pedal travel? I DO NOT know.

My few brain cells say the issue is simply air in the system. My low back is sore from hunching over my f*cking brake booster for the second time in six months. I HATE having to remove it twice and I had to remove it again today in order to replace the Master Cylinder.

Thoughts/discuss/thanks.

[mattmartindrift]

I say just cut losses and go to the dealer or indy with the proper tools and get it done the "proper" way.

[NNY528I]

take it to the dealer, the valves need to be cycled to properly bleed an ABS type system if air has gotten into that part of the system

[nighttowl]

go to kragen autozone pepboys napa and pick up a 29 dollar hand vacuum brake bleeder kit. they work great. i also have one that is compressed air powered, but it sucks the master cylinder empty too fast, so i dont use it.

the one below works great for me, and ive had it for 3 years with no problems. work every penny and then some.

http://www.autozone.com/autozone/cat...roductId=70116

[mattmartindrift]

did you have water/air trapped in your ABS system?

[bimmerfiver]

take it to the dealer, the valves need to be cycled to properly bleed an ABS type system if air has gotten into that part of the system

I believe you are 100% CORRECT. And I don't want you to be. And I don't want to be. It sucks. I am going to be up at 4am, fishing trip at 6am. If a shark eats my boat and me, I leave my e39 to mmm635 and my last wish is that he addresses my brake system once and for all.

Having replaced my Brake Booster, Master Cylinder, Reservoir, all rotors, pads and fluid (fluid has been changed about six times in six months)...I am pissed I gotta go to the dealer for a brake bleed. Makes me feel like an R2 unit with a bad motivator.

[reyes3]

I'm having the same problem and am interested to hear if that fixes it.

[thetinpusher]

I have used this technique on brakes as well as the clutch system. Air naturally wants to stay on top of a fluid, trying to force it down to the bleed screw goes against mother nature..... check out the following u tube vid

[ame]http://www.youtube.com/watch?v=wdf--suwqw0[/ame]

[NNY528I]

I have used this technique on brakes as well as the clutch system. Air naturally wants to stay on top of a fluid, trying to force it down to the bleed screw goes against mother nature..... check out the following u tube vid

http://www.youtube.com/watch?v=wdf--suwqw0

While this is all wonderful it has nothing to do with bleeding an ABS system. there are areas in which air gets trapped that are isolated from the flhjd flow path during normal operation, the valves need to be cycled to remove this trapped air and restore the system to proper operation.

[nighttowl]

From BMW's TIS software, see attached.


looks like they pull the fluid through the system. doesnt say anything about cycling the abs system.

[cnn]

See quote below from Bentley. Anyway, before heading to the dealer to accept defeat...LOL...try the trick below.

1. If you have not done this $10 cap for a pressure bleeder, then do it using this ATE cap. I wrote it up here using regular air compressor:

http://forums.bimmerforums.com/forum....php?t=1297495

2. Carsoft cannot cycle the ABS electrical valves.
However, you may want to give this a try:
- Do a quick search to learn how ABS works. Basically the Hydraulic Modulator (the portion with brake lines) is controlled by the Electrical Component (a whole bunch of solenoids activated by the ABS ECU).
- Whenever people complain about bad ABS Module, it is usually Electrical Component and not the Hydraulic Modulator.
At dealer, the software opens and closes these valves to expel any trapped air out of the ABS Module while they bleed the system.

Options:
1. Dealer to bleed air out of ABS Modulator: expensive!

2. You can DIY if you are "ready and willing". You need an assistant.
- Remove the Electrical Component: You will notice that there are 12 valves total, 3 per circuit (4 circuits/car):



- Now figure out which circuit goes to which wheel and ask an assistant to press down on the three (3) valves that control let's say circuit "A" while you bleed the brake caliper from circuit "A". By pressing down the 3 valves, all the air is expelled out of the ABS Modulator when you open the bleed nipple on the brake caliper of that particular circuit!

- Again read my DIY and do NOT ever let air inside the Reservoir ---> ABS Modulator b/c you will start all over again.

Post a follow-up!

The BMW Service Tester must be used to bleed the brakes if:

• Any hydraulic system components are replaced, including brakes lines.
• Air has entered the ABS/ASC or ABS/DSC hydraulic unit.

Warning--

• The ASC and DSC systems use electronic controls and a sophisticated hydraulic unit. Once air enters thehyrdaulic unit, it is very difficult to remove using traditional methods. For this reason, pressure brake bleeding should be done in conjunction with the BMW Service Tester. The tester electrically cycles the hydraulic unit solenoids in the hydraulic unit while pressurized brake fluid is forced through the system.
• When flushing the brake fluid from the system, use extreme care to not let the brake fluid reservoir run dry. If air enters the hydraulic unit, the BMW Service Tester MUST be used to bleed the brake system before the vehicle is driven.

This is another nice lecture on how the ABS Hydraulic works. Actually it is very simple when you look at it, when the wheel begins to lock up, the sensor sends a signal to the ABS computer to open "Valve C" basically allowing hydraulic fluid to return to the loop. Then the wheel stops slipping, then "Valve C" is closed in milliseconds later:

http://www.cvel.clemson.edu/auto/systems/braking.html

[nighttowl]

so the closing and opening the valves get the air out of the a-c and c-b circuit, right? which is why hes not getting full pedal. interesting. i thought the circuit would be a little simpler than it is.

[bimmerfiver]

[QUOTE=cnn;19545375]See quote below from Bentley. Anyway, before heading to the dealer to accept defeat...LOL...try the trick below.

2. Carsoft cannot cycle the ABS electrical valves.
However, you may want to give this a try:

At dealer, the software opens and closes these valves to expel any trapped air out of the ABS Module while they bleed the system.

Options:

2. You can DIY if you are "ready and willing". You need an assistant.
- Remove the Electrical Component: You will notice that there are 12 valves total, 3 per circuit (4 circuits/car):



- Now figure out which circuit goes to which wheel and ask an assistant to press down on the three (3) valves that control let's say circuit "A" while you bleed the brake caliper from circuit "A". By pressing down the 3 valves, all the air is expelled out of the ABS Modulator when you open the bleed nipple on the brake caliper of that particular circuit!

[QUOTE]

I have to tackle this before I gain more gray hair.

Bleed the brakes again last night, no change. It's clear and apparent the air will not come out by the standard/oldschool method.

To this end...I am certainly capable and willing to address it before I go to the dealer with my tail between my legs. Are you saying:

1). Unplug the large connector for the ABS (located in front of it).
2). Should the battery be disconnected? (important question).
3). Fill reservoir to top.
4). Figure out the roadmap/schematic of the 12 'male end fittings' within the ABS Module, which wheel each of it's 3 go to.
5). Start at the right rear wheel...open the nipple on the brake caliper WHILE someone (wish I had an R2-D2 unit) you trust SIMPLY pushes those 3 male-end fittings in the ABS Module, which forces fluid through the system.
6). Perform on all four wheels.
7). Perhaps overkill, but at this point, bleed all 4 wheels again using the method above.
8). Perhaps overkill, but then bleed all 4 wheels again at the brake caliper nipple whilst having the brake pedal pushed (oldschool).

9). Last thing---has anyone done the above 'Open your ABS and do it manually'?

Thanks

[Jason5driver]

Cnn-
Your posts never cease to amaze me!
Awesome! Thank you!

Sir BimmerFives -
I truly wish I could be there to help battle with you!
I have a feeling that Michel would want you to use the Motive Brake bleeder.
I would most definitely do the technique that CNN mentioned.
Let me know.

Thanks!
Jason

[bimmerfiver]

Bleed the brakes four times today. Pedal is better, but the brake pedal still has too much travel imho and it is somewhat spongy in that you can force the pedal down too low if you sit on the pedal.

Very little air, perhaps six tiny bubbles came out the whole time. I am beginning to suspect one or both of these and my first guess is # 1:

#1 possibility - I didn't bench bleed the master cylinder well enough

# 2 possibility - there is air trapped in the ABS Module

If it is # 1 above---I AM NOT going to remove the brake booster/master cylinder and bench bleed again. To this end, any advice for # 1 above?

Thanks.

[NNY528I]

just bit the bullet and take it to a pro and get it bled properly. I went through similar headaches with the clutch on the MG, took me 2 weeks to narrow it down to a contaminated seal in the MC. eventually you will get it but you will have no hair and be overly stressed not to mention all the money you will spend on replacement parts that weren't needed.

[bimmerfiver]

I could not and cannot bite the bullet. It was a matter of principle.

While using a one-man bleeder, a primitive but effective tool, along with 3 quarts of Castrol GTLMA Brake Fluid and taking the e39 for spirited drives to activate the ABS System*, I was able to, over the course of 5 hours and 10 bleeds per wheel---able to remove a few air bubbles. Enough that my pedal is MUCH firmer.

The brakes are prolly at 95%. I will forge ahead to locate those bubbles. I will.

* = the belief is this the raw/manual way to cycle the ABS. I believe it works.

[NNY528I]

for what that cost you in time and fluid you could have paid someone to bleed it out and had a few bucks left over to take the woman to dinner. Gotta love principles...

[occhis]

Gotta love it. An all-out war on air bubbles. Forge ahead, and fight the good fight.

[bimmerfiver]

Gotta love it. An all-out war on air bubbles. Forge ahead, and fight the good fight.

Somehow Adrien friggin Brody got the lead in this summer's remake of Predator which should've been my role. Instead I will not relent on these air bubbles. Gonna suck:

http://io9.com/5492607/adrien-brody-...-for-predators

[Jason5driver]

for what that cost you in time and fluid you could have paid someone to bleed it out and had a few bucks left over to take the woman to dinner. Gotta love principles...

Yes, I agree.

Mr. Fiver,
What method are you using to bleed the brakes?

[bimmerfiver]

What method are you using to bleed the brakes?

Post # 17 above, "While using a one-man bleeder, a primitive but effective tool, along with 3 quarts of Castrol GTLMA Brake Fluid and taking the e39 for spirited drives to activate the ABS System*, I was able to, over the course of 5 hours and 10 bleeds per wheel---able to remove a few air bubbles."

Brakes are much better. But not perfect. Just returned from Starbucks. Chicken Salad sandwich, Venti iced tea with some lemonade to sweeten it and a 40 minute power nap. Their chicken salad sandwich is good, though high salt content imho. Salt is the devil. Drove around, brakes are very good, not perfect as you can push the brake pedal down TOO FAR at RED LIGHTS/WHEN STOPPED...telling me AIR is still in there.

[Jason5driver]

Post # 17 above, "While using a one-man bleeder, a primitive but effective tool, along with 3 quarts of Castrol GTLMA Brake Fluid and taking the e39 for spirited drives to activate the ABS System*, I was able to, over the course of 5 hours and 10 bleeds per wheel---able to remove a few air bubbles."

Brakes are much better. But not perfect. Just returned from Starbucks. Chicken Salad sandwich, Venti iced tea with some lemonade to sweeten it and a 40 minute power nap. Their chicken salad sandwich is good, though high salt content imho. Salt is the devil. Drove around, brakes are very good, not perfect as you can push the brake pedal down TOO FAR at RED LIGHTS/WHEN STOPPED...telling me AIR is still in there.

Roger that.
Would that Motive brake bleeder help?
Have you talked to Michel?
Do the StopTech pads bite as good as the Jurids?

[bimmerfiver]

Roger that.
Would that Motive brake bleeder help?
Have you talked to Michel?
Do the StopTech pads bite as good as the Jurids?

Motive brake bleeder...is this the kind/type that draws fluid OUT at the brake bleeder's nipple or forces fluid IN at the brake bleeder's nipple? OR does it force fluid in at the Master Cylinder? (note there's 3 questions there).

As for StopTech---I cannot say as my brake pedal ain't as hard as:

Kayden Kross'
Sarah Vandella's
Raven Alexis'
Edelweiss'
Suzie Carina's

n*pples.

note: the above ladies are very NSFW.

[Jason5driver]

Motive brake bleeder...is this the kind/type that draws fluid OUT at the brake bleeder's nipple or forces fluid IN at the brake bleeder's nipple? OR does it force fluid in at the Master Cylinder? (note there's 3 questions there).

As for StopTech---I cannot say as my brake pedal ain't as hard as:

Kayden Kross'
Sarah Vandella's
Raven Alexis'
Edelweiss'
Suzie Carina's

n*pples.

note: the above ladies are very NSFW.

I don't know about the Motive system.
Michel does.
I am guessing the fluid is pushed from the Motive reservoir through the master brake cylinder.

http://www.motiveproducts.com/

http://www.apexperformance.net/CartGenie/prod-1986.htm