Bleeding Brakes W/ASC+T???

[Jehu]

WARNING

-


On car

s with Automatic StabilityControl + Traction


(ASC+T). special BMW service equipment is required to properly bleed the ASC+T/ABS system.For


safety reasonsthe brake system on cars with



ASC+T must not be bled using the procedures described below.


BLEEDING BRAKES....


so I have to have the dealer or a BMW Indy bleed my brakes? Is the issue strictly being careful not to allow air to either enter thru the reservoir from low fluid or backing in the bleeder hose ? Just ordered a pair of ATE Slotted Rotors and have the Akebono Euros ready to go on this Friday over at a General mechanic shop but when I read this .... what's the deal will these grease monkey's fook up my Brake System or if they're experienced enough can they do it safely without whatever tool BMW uses?

[Russell]

You do not need to bleed brakes to change rotors and pads. I have done it twice on my car with ASC+T with no problems. That said, my bmw indy bled my brakes about two years ago. Did not notice how he did it.

[shogun]

It can be very difficult. We did that some month ago on an E32 750iL 12/1992 with ASC+T.
Bleeding, bleeding, bleeding, pumping was still soft. Almost wanted to give up, then tried again and pumped and pumped for maybe 30 minutes, then suddenly it 'burped' down in the engine room near the regulating unit and the air was out.
I cannot tell you the exact method how it should be done, we did it the usual way, and that apparently created some problems. So better check carefully the proper method and what equipment might be necessary.

[Jehu]

Thanks Shogun. Russ I have yet to change the fluid in the nearly 120,000 i've been driving it and the pedal is feeling a bit soft.Pedal doesn't go to the floor but the info about corrosion from old fluid scares me, as i think it should...

[Russell]

I see. Yes by all means change the fluid. Does BMW still state, change fluid every two years?. I would use a mechanic knowledgable of BMW brake systems.

[pgrindstaff]

In BMW's GT1 and other bmw diagnostic software such as ediabas/inpa there are options for bleeding the brakes. I do not know exactly how this works but believe it manipulates the ABS and ASC+T systems. That being said, there is no way I am going to press the button for bleeding the brakes unless I am actually going to bleed my brakes. It would definately be interesting to see exactly how it works though.

[Jehu]

In BMW's GT1 and other bmw diagnostic software such as ediabas/inpa there are options for bleeding the brakes. I do not know exactly how this works but believe it manipulates the ABS and ASC+T systems. That being said, there is no way I am going to press the button for bleeding the brakes unless I am actually going to bleed my brakes. It would definately be interesting to see exactly how it works though.


Wow,,, sounds serious..lol.. thanks I'll have the dealership do it.

[shogun]

In many countries there is even a warning light in the cluster with a clock sign, that reminds you of the annual service to be done which includes brake fluid change.

The airbag/SRS/oil/service reset tools I am selling even include such a reset function with the clock sign, see pic here
http://www.bimmerboard.com/forums/posts/551746
That unit is made in Germany and German E34 and E32 and other models have this warning clock sign.

[Jehu]

In many countries there is even a warning light in the cluster with a clock sign, that reminds you of the annual service to be done which includes brake fluid change.

The airbag/SRS/oil/service reset tools I am selling even include such a reset function with the clock sign, see pic here
http://www.bimmerboard.com/forums/posts/551746
That unit is made in Germany and German E34 and E32 and other models have this warning clock sign.


I unplugged my Instrument Cluster wires without disconnecting my battery and now when I start the car the SRS light stays on for longer than normal, a few minutes but does go out. Will this tool fix that syndrome? I have honestly just been forgetful about this element of standard maintainance. It slipped my mind until i began planning to replace pads and rotors due to a slight warp in a front rotor discovered recently when I had new tires put on.

[shogun]

For such a case it is made, it cannot cure a problem such as a broken wire, it just resets the ewarning after a repair, that is why I mention in the specification:

Note: the SRS system on your BMW needs to be functioning properly in order to reset the SRS light. If the system detects a fault on any of the systems sensors a reset without replacement of those failed components is not possible.

[Jehu]

I assume the wires remained intact. I had unplugged the three plugs to allow the replacement of a bulb illuminating the Engine temperature Gage,I don't suspect I broke any wires but i suppose it must at least be possible though the several times before I did disconnect the negative cable from the battery. I can live with the SRS light lingering on if it is not indicative of a potential ignition of the airbag independent of a collision.. Tight budget at the moment but I saved your link.

[Blitzkrieg Bob]

I assume the wires remained intact. I had unplugged the three plugs to allow the replacement of a bulb illuminating the Engine temperature Gage,I don't suspect I broke any wires but i suppose it must at least be possible though the several times before I did disconnect the negative cable from the battery. I can live with the SRS light lingering on if it is not indicative of a potential ignition of the airbag independent of a collision.. Tight budget at the moment but I saved your link.

If you didn't remove the steering wheel, then I would think that you are okay, and just having an OCD moment over the timing of the SRS light on start up.

It does go out after a few seconds...right?

[Jehu]

If you didn't remove the steering wheel, then I would think that you are okay, and just having an OCD moment over the timing of the SRS light on start up.

It does go out after a few seconds...right?

Yep ,goes out eventually just seems to remain on longer than I remembered it..

[philbyil]

This was posted on the Z3 board and the source is Pelican Parts.

---- from Mike Miller ----

Brake Bleeding 101

Initially, many of you question the admonitions and procedures set forth in the Bentley service manuals for newer Bimmers. Bentley is sometimes compromised by the necessity of placating BMW of North America’s legal department. The chief concern with bleeding brakes on a DSC-equipped BMW is that you not introduce air into the system. If you do, it is doubtful you will get it out without cycling the ABS valves, which requires the BMW DIS tester. The DIS tester (and MoDIC) is the “special service equipment” referred to in the Bentley manuals.

As long as you don’t introduce air into the system, it’s okay to bleed your own brakes. Be advised that the procedure in the Bentley manual for depressing the brake pedal 5 times with the bleed screw open, holding the pedal down on the last pump until the fluid is free of bubbles, and then closing the screw and releasing the pedal is referring to the “pump the pedal” method. They mean for you to CLOSE the bleeder screw before releasing the pedal after every pump! This is not necessary as long as you use a Vacula bleeding tool.

I advise against the "pump the pedal" method for two reasons. First, it does not allow for evacuation of and removal of dirt from the master cylinder reservoir. Second, by pumping the pedal, it is very easy for the brake master cylinder piston to exceed its normal range of travel. If there is a bit of rust or dirt on the piston, and the piston exceeds its normal range of travel, damage to the seal and master cylinder failure can result. Moreover, it requires two people and takes a long time.

Pressure bleeders work better, and have the advantage of being inexpensive tools for the most part. They also pressurize the system slightly to aid in clutch hydraulic work, and guard against introduction of air into the system -- which is the primary concern the Bentley folks have with these cars. If you introduce air into the system on a DSC or ABS car, it is entirely likely you'll have to make a trip to the dealer so they can use their DIS tester to cycle the ABS valves during a brake fluid change. However, pressure bleeders don't evacuate or remove dirt from the reservoir either, and there is a risk of contaminating the fresh brake fluid in the machines holding tank and hoses.

My preference is for brake fluid suction tools. These require an air compressor, but as a practical matter anyone working on cars should have a compressor anyway. The suction tools allow the master cylinder reservoir to be vacuumed out using a piece of old brake pipe or similar implement. You then refill the reservoir with fresh brake fluid, and go to each caliper or wheel cylinder and use the tool to draw out the brake fluid until it runs clean through the clear hose. It's simple, and fast. But it's not cheap. The best suction tool I've ever seen is called a Vacula, and costs about $168 from Griot's Garage (www.griotsgarage.com), which calls it a "One-Man Brake Bleeder". This tool is also available from Snap-On tool trucks, but believe it or not, Griot's is cheaper even with shipping. It’s a pricey tool commitment, but versus paying someone to change your brake fluid, and the attendant hassle of getting the car there and picking it up later, the tool pays for itself eventually.

© 2001 Mike Miller










WARNING

-


On car

s with Automatic StabilityControl + Traction


(ASC+T). special BMW service equipment is required to properly bleed the ASC+T/ABS system.For


safety reasonsthe brake system on cars with



ASC+T must not be bled using the procedures described below.


BLEEDING BRAKES....


so I have to have the dealer or a BMW Indy bleed my brakes? Is the issue strictly being careful not to allow air to either enter thru the reservoir from low fluid or backing in the bleeder hose ? Just ordered a pair of ATE Slotted Rotors and have the Akebono Euros ready to go on this Friday over at a General mechanic shop but when I read this .... what's the deal will these grease monkey's fook up my Brake System or if they're experienced enough can they do it safely without whatever tool BMW uses?

[Jehu]

This was posted on the Z3 board and the source is Pelican Parts.

---- from Mike Miller ----

Brake Bleeding 101




That's great info right there.. Sounds like I might want to bring it by BMW anyway to get it done 100%. I just made an appointment for next Monday, quoted me $130 and they'll do it while I wait. Not having any idea of the type of maintainance done before I aquired the car two years I think it'll be worthwhile. Thanks. for the info.

[Blitzkrieg Bob]

$168?

I just use a syringe to empty the reservoir of the old fluid and get one of my kids to pump and hold to pedal down.

P.S. you may want to check the grommets that hold the reservoir on the master. They tend to rot out and fail right around the time your doing this.

[Bill R.]

really want to use the vacum tool to bleed them from the caliper fittings you can get one from Harbor freight thats just as good as vacula... I use it if i don't have someone to help me bleed in my preferred method. It goes on sale all the time at harbor freight for 19.99, normal price is 29.99. You have to remove the bleeder screws and wrap the threads with teflon tape before bleeding each caliper so that when you apply vacum at the bleeder screw it can't suck air around the threads on the bleeder screw.

The only drawback to those vacum brake bleeders is they use quite a bit of compressed air so you compressor runs continously while using one.