[copperstatetour]

I had to replace a brake line and feel that it would be prudent to bleed the ABS unit at the same time I bleed out the rest of the system - the question is how? It seems to me that I could bleed the module from the two bleed screws on top of the module in the same fashion I would bleed the calipers.

I have done some searching of the forum and can't really find any instruction on this but only some vague reference to this being a massive procedure.

Again, this is on a 2000 and it is before the new-fangled integrated brake system.

 

[amarider]

Fairly simple with speed bleeders.
The rear bleeder on the ABS unit( toward the back of the LT) is for the rear circuit.
There are two bleeders on the rear caliper, one on each side.
I bleed the caliper first one bleeder at a time then the abs unit. IF you are only doing the rear then just the rear bleeder. Be sure not to run the reservoir dry at any time.
Again I can not stress the need for speed bleeders ( two for the front wheel, two for the rear and two for the ABS) You can get these at any BMW shop or order them at about $7 - $10.
Bleeding without them is a major pain.

The ABS unit is split and does not mix the rear and front circuits on the 2000.

 

[gary45]

I just bled my 2000 at the calipers, nothing special, length of tubing elevated above caliper then into pan, bleed screw just open enough to pump fluid, other threads suggest bleeding ABS unit not necessary - always worked for me on any car have ever had bleeding by myself

 

[jzeiler]

The module bleed ports are just two high points in the system. Bleed the circuit you replaced the line on from the reservoir to the caliper. Once the air is gone from that then pull what little may have been trapped in the ABS module. HF for front, HR for rear.

I don't care for speed bleeders but I do Love thier bleeding bag and tubing ($6.00). Install the tubing, elevate the bag and open the bleed nipple while you pump away. Air will not go down the elevated tubing and it is a one man job.

 

[jackd]

I agree speed bleeders are not necessary but make the job a lot easier for a part time mechanic. If you use speed bleeders you might invest in a small hand operated vacumn pump. Also works better if you put a wrap of Teflon tape on the threads of the bleeder if you use a vacumn pump.

When you are done with calipers then do the bleeders on the top of the modulator.

 

[copperstatetour]

Thanks for the info guys, I didn't think it seemed too insanely complicated but some of the posts I read made it sound that way, going to tackle it tomorrow - wish me luck! :wave

 

[14wntr]

good luck. I have a 2000 as well and can tell you its not that hard. I use a vac bleeder and have stellar results.

 

[jzeiler]

Thanks for the info guys, I didn't think it seemed too insanely complicated but some of the posts I read made it sound that way, going to tackle it tomorrow - wish me luck! :wave

The later model bikes have a some what more complicated procedure as they are linked and have four seperate circuits to work with. Sometimes simpler is better.

 

[Razmataz]

I don't care for speed bleeders but I do Love thier bleeding bag and tubing ($6.00). Install the tubing, elevate the bag and open the bleed nipple while you pump away. Air will not go down the elevated tubing and it is a one man job.

John your writeup on this is flawless to me. Admittedly I was nervous the first time, but I've done it twice now, and the brakes work great.

 

[jzeiler]

Glad I could be of assistance.

 

[DrSuess]

Hello,
Newbe here but have been reading threads for about a year. I am getting ready to flush my brakes and thought I had all the correct info but just read this old thread from M Neblett and was wondering if it is correct?? The thread is below.

"If I recall correctly (read my Integral brake bleeding Word .doc in the Files section** to verify), the rear half of the rear dual reservoir is the reservoir for the rear brake actuation circuit (feeds fluid to the Integral unit for the rear actuation circuit -- level in this reservoir will drop as the rear pads wear).

The front half of the rear dual reservoir serves both the front brake actuation circuit (leading to the Integral unit) and the rear brake pedal control circuit (hose leading to the rear brake master cylinder behind the footpeg plate -- this reservoir 's level will decrease as the front brake pads wear).

**http://www.bmwlt.com/files/displayi...album=15&pos=11 -- note in the picture on page 10 that there are two hoses coming out of the bottom of the front half of the rear dual reservoir -- one to the Integral unit's front brake actuation circuit, and one to the rear master cylinder."

HTH,
__________________
Mark Neblett
I thought front portion of the reservoir was for the rear control circuit and the rear calliper (two hoses), while the rear reservoir is for the front calliper only (one hose)???

 

[copperstatetour]

So I purchased and used speedbleeders and am more or less unimpressed. I found I needed to tighten them down much further than I am comfortable in order for them to stop 'bleeding' - certainly more than the 10Nm prescribed in the service manual.

I bled the front system (where I replaced the hose) and after running 2 pints of fluid through the front half I still feel that the brakes are spongy . I didn't get any bubbles after the first pint, but the spongy feeling never went away. I do encounter significant resistance, but I can still draw the brake lever all the way to meet the grip. I cannot do that on my R1200C of the same year which I believe has basically the same system. I bled the left caliper, then right, then ABS, did it 3 times and no bubbles but still no improvement.

I was not able to replace the filler tube on the right caliper with a bleedscrew because it failed to seat . I think the previous owner may have 'modified' the brake caliper in some way so that the bleed screw does not make contact and seat properly (speculation).

I am open to any ideas

 

[amarider]

Now does the lever meet good resistance with an easy pull then if you hold does it slowly go all the way to the grip?
If so it could mean the master cylinder is leaking past the seals.

If not then you still must have some air trapped, maybe because of right caliper trouble? I had a hard time with the right side because of the factory filler. I'm going to remove it for good next time around.

The only thing I noticed about the speed bleeders was that they had a health coating of sealer on the threads. Made it a little hard to tighten the first time but was normal after that.

 

[copperstatetour]

Now does the lever meet good resistance with an easy pull then if you hold does it slowly go all the way to the grip?

I have to continually apply additional pressure to make contact with the handgrip but I can do it with one hand. I'm sure there is air in there somewhere, I just don't know where or have any idea how to remove it.

I probably need to find a caliper and start there, then at least I could get rid of that ugly filler/grub screw thing.

 

[jzeiler]

I was not able to replace the filler tube on the right caliper with a bleedscrew because it failed to seat . I think the previous owner may have 'modified' the brake caliper in some way so that the bleed screw does not make contact and seat properly (speculation).

I am open to any ideas

You can leave the fill adapter on and just replace the grub screw. Or you can heat the fill adapter and remove it completely and replace it with a regular bleed screw. Make sure you remove all of the threaded part of the fill adapter as it may have broken off.

If your lines are still spongy then consider replacing all of them. If you had one fail the rest are about to and are likely expanding under presssure. If yours is a 2000 those lines are now at least 12 years old or more.

I don't use speed bleeders either but I love the hose and bag they sell for $6.00. That makes it a one man job with standard bleed screws.

 

[amarider]

I agree with replacing the lines (spieglar), I just did that this last winter on my 01.
Have you check the old lines to see if your getting a bubble anywhere when under pressure?

 

[14wntr]

How are your pads? If they are too far gone you may have trapped air in the caliper. Try pushing them back and wedging them. I can gravity bleed my 2K. X2 on the replacement with Spieglers. My brakes are remarkably crisp now that I changed mine out! I think mine were stretching under pressure.

 

[copperstatetour]

Update:

After pushing more than a quart of brake fluid through the front half of the system I finally figured it out - the problem that prevented me from getting the air bubble out was technique:brick:

Apparently I was squeezing the handle like a sissy when bleeding, I was using a steady, slow squeeze to push the fluid through. I finally resorted to quickly smashing the brake lever from full open to handgrip with the bleeders open. That did the trick, the bubbles started flowing and after a few more dollars of fluid I now have a solid feeling brake lever.

I used a milk cap to float on top of the fluid in the reservoir to keep the fluid from squirting up during the rapid pulses and it worked like a charm.

If nothing else, I have thoroughly flushed my brake system