ABS Brake Bleeding ???

[warthog]

Need to bleed my brake system on my 91 K100LT and the Clymer book indicates that the ABS systems require the dealer to hook them up to a power bleeder. Called the dealer and they have a three week waiting list for work. Have called a couple other motorcycle dealers in the area and they will not touch a BMW.

Any ideas? I had to disconnect the front line when I was removing the front fender and air got into the system.

[HODAG]

I bleed mine like normal?

ABSI

[warthog]

Mark I was hoping that was the case. Did not know if having the dealer do it with a power bleeder was mandatory or just a recommendation.

Don

[PHMARVIN]

Hi, Don,
Since you got air into the system, it's probably better to use either a power bleeder or a vacuum bleeder, BUT it is possible to do it the old fashioned way - loosen, squeeze, tighten, let go, repeat as much as necessary. Just be sure you use short strokes, not squeezing the lever more than halfway. You don't want the piston in the master cylinder to be trashed as it passes over crud (technical term) past where it had normally traveled. And if you are just changing brake fluid, gravity works. I attach a hose to the bleed connection and place the end of the hose in a bottle with about an inch of brake fluid in it. I do the open,squeeze, tighten, let go, repeat until bubbles no longer come out of the hose. Then I leave the bleed connection loose and let the brake fluid siphon through the sustem, making sure the reservoir doesn't fully empty. It works for me.

[boomyr]

I bled the brakes on my '96 K1100 pretty much the same way I did on a friends '88 K75.

Need to bleed my brake system on my 91 K100LT and the Clymer book indicates that the ABS systems require the dealer to hook them up to a power bleeder.

The line you mentioned in the Clymer manual caused me to hesitate bleeding the brakes on my ABSII system for a while for fear that I would destroy the ABS system if I attempted to flush the system myself. The hesitation proved to be more damaging than bleeding the brakes, and I ended up having to rebuild the master cylinder.

I bled the master cylinder with a Miti-Vac (just because I happen to have one), but I don't think that you need to do anything beyond pumping the lever and pedal. An advantage of using a Miti-Vac is that you have constant pressure coming out of the bleed valve, so no air is getting in.

I also bled the ABS unit under the seat (it has it's own bleed valves) using the brake pedal and lever. Most of the ABS unit fluid was flushed when the master cylinder was flushed through the system. When I flushed the ABS unit only about a teaspoon of dirty fluid was extracted, then it was clean fluid. I believe if you flush the master cylinder fluid regularly, it's probably not necesary to bleed the ABS unit. I was told by another member whom I feel is very competent, that there is a small cavity at the top of the bleed valve that "traps" a small amount a fluid from circulating during the master cylinder flush. When the ABS unit is bled, it is then extracted.

There's no reason that you can't do it yourself (dispite Clymer's advice). If you get into an area that makes you unsure, or need more info, post it on here or the KOG site, and I alway have had my questions answered.

Good Luck!

[warthog]

I decided that I would give it a try myself. I stopped by Autozone on the way home and picked up the Actron system for about $49 and a large container of brake fluid just in case. Using the Actron system I was able to get most of the air our of the front system. I have not done the rear yet because I wanted to see how the front turned out. Took her out for a test drive tonite and no problems.

When I get time I will give the rear a shot seem pretty straight forward.

Thanks for all the input. I also read the article on ibmwr about the Actron system.

Don