Bleeding ABS brakes

[dale]

Yep, this has been posted before


You clever cats skip right over the juicy stuff!


I'd like to bleed my brakes since i had the front brake master cylinder upside down for a few months (don't do this) and now my front brake caliper is locked up on the disk.


In regards to bleeding the abs, what do you lot do? I have read a lot of "just do it the normal way" and seen many people online just skip the ABS and do the caliper only... i would like to do the abs as well and looking for help (k1100LT 1999)




Best regards,
Dale

[The Mighty Gryphon]

First off, you aren't just bleeding the brakes, but flushing the old fluid out and replacing it with fresh fluid.

There is nothing special about the technique.  Put a length of vinyl tube on the bleed fitting and run it down into an old gallon milk jug that is half filled with water.  Stick the tube down into the handle of the jug so it won't pull out and dump fluid on anything.  The water in the jug helps keep it from moving and tipping over, as well as diluting the old fluid so if you do spill it it won't be so nasty.

First spot to bleed is the ABS Modulator.  With an 11mm wrench open the bleeder and then slowly squeeze the brake lever.  When it stops, close the bleeder and slowly release the lever.  Keep repeating until you get nice clear fluid coming out, or until you have pumped at least 3 ounces of fluid through the system. 

When you're done, use a wet rag to pull the tube off of the bleed fitting, wipe the fitting down with the wet rag to remove any remaining fluid.  When the ABS Modulator is done, go to the Calipers, and repeat the process.  On some bikes there is only one bleeder on the front, on bikes with two it doesn't matter which one you do first because they are split at a wye. 

[stokester]

First off, you aren't just bleeding the brakes, but flushing the old fluid out and replacing it with fresh fluid.

There is nothing special about the technique.  Put a length of vinyl tube on the bleed fitting and run it down into an old gallon milk jug that is half filled with water.  Stick the tube down into the handle of the jug so it won't pull out and dump fluid on anything.  The water in the jug helps keep it from moving and tipping over, as well as diluting the old fluid so if you do spill it it won't be so nasty.

First spot to bleed is the ABS Modulator.  With an 11mm wrench open the bleeder and then slowly squeeze the brake lever.  When it stops, close the bleeder and slowly release the lever.  Keep repeating until you get nice clear fluid coming out, or until you have pumped at least 3 ounces of fluid through the system. 

When you're done, use a wet rag to pull the tube off of the bleed fitting, wipe the fitting down with the wet rag to remove any remaining fluid.  When the ABS Modulator is done, go to the Calipers, and repeat the process.  On some bikes there is only one bleeder on the front, on bikes with two it doesn't matter which one you do first because they are split at a wye.

I just replaced the brake lines in my K75S w/ABS and a brake pressure bleeder makes short work of bleeding or flushing.


What Gryph is describing is the way I've done it many times on both motorcycles and cars and it works just fine but can be a PITA.  I've also used a MityVac as well as a Motive Products pressure bleeder on my cars.  With the need to change out fluid every couple of years in both my vehicles and cars I was always looking for an easier way.  While working at the Chevy dealership I used various methods and found this brake bleeder made the job fast and easy.

[The Mighty Gryphon]

Those pressure bleeders are really nice, but how do you connect them? 

[johnny]

greetings...

i gotts a never used mityvac cause nobody on the mityvac forum would tell me how to use it...

j o

[stokester]

Those pressure bleeders are really nice, but how do you connect them?

It has a rubber connector that fits tightly over the bleeder.


- hook up bleeder to shop air
- put box end wrench on bleeder
- connect rubber connector over bleeder
- be sure master cylinder is full (if bleeding it's a good idea to evacuate it and fill with new fluid)
- pull trigger on pressure bleeder and use lock if desired (there is a vacuum pressure limiter)
- open bleeder, look for bubbles and clean fluid
- monitor master cylinder level, fill as necessary
- tighten bleeder screw under vacuum then release trigger and remove hose

[The Mighty Gryphon]

Got it!  You have an air operated VACUUM bleeder.   It uses air pressure in a venturi to create the vacuum that pulls the brake fluid out of the system. 

I was thinking you had a bleeder that used the pressure to push the fluid through the system.  That would require some sort of attachment to the top of the reservoir.

[stokester]

Got it!  You have an air operated VACUUM bleeder.   It uses air pressure in a venturi to create the vacuum that pulls the brake fluid out of the system. 

I was thinking you had a bleeder that used the pressure to push the fluid through the system.  That would require some sort of attachment to the top of the reservoir.

Yes, you're right it's vacuum, poor choice of words.


I do have a Motive Products pressure bleeder which uses a plastic container and requires adapters for the reservoir which are expensive so I have ones for VW bugs and GM products only.  While it would be possible to make an adapter for motorcycles I think the vacuum unit works best.

[The Mighty Gryphon]

Yeah, I got a great deal on a power bleeder last winter, and then saw what it would cost me to make it work with four different reservoirs.  So far, all I have are two covers for the rear brake reservoirs on my K75's and K100RS4V.  Even with the covers, the setup of everything is a bigger PIA than bleeding the old way.

[Martin]

Mk 2 Nescafe vacuum bleeder you need a suction gun, Nescafe jar, 2 x 1/4 bulkhead fittings, copper tube, and some hose. Mk 1 Dolmio Pasta Sauce version finally kicked the bucket when the lid would not seal after about 30 years of use.
Regards Martin.

Brake Bleeder Nescafe Mk2.jpg (49.68 kB . 768x576 - viewed 1743 times)

[alexis291]

A vacuum pump has worked a treat on my 1995 K1100 RS on front and rear brakes. Bleed the ABS unit first. Can I suggest you check that your caliper pistons aren’t stuck. I am in the process of rebuilding my calipers because one of the pistons was so tight I had to drill and tap it to get it out. This is on a bike that is used most days.

[dale]

Hi everyone,
Thanks for the replies!


Yes alexis my pads are pressed up against the disk.
I thought this was because of my left side of handle bar hanging low for such a long time. When i flush the brakes ill try and manipulate the pads so that they return to normal.


Is the picture which stokster posted the abs bleed point? If so... i dont want to share where abouts i was trying to bleed from :hehehe

[alexis291]

When i flush the brakes ill try and manipulate the pads so that they return to normal.

I would just make sure the pistons move in and out freely. The one which stuck in my calliper moved in by hand but then jammed. 100psi air pressure wouldn’t move it out again.