Brake bleeding ABS II system

[Rolland]

I have replaced all the rubber brake lines and new pads, got the rear brake working great good solid pedal this is on the R1100RSl. The front set I am having a little trouble, I have to pump the handle up a couple of times to get what I would be a solid feel on the brakes. I have bled them and am getting no air bubbles altho I think there must be in the system ,  Is there a trick to getting the front better. I did have good brakes prior to losing the front hose and some fluid.

 

[Michaelr11]

Try pumping up the front brake lever good and solid, then hold the lever and tie some string or rubber bands around the lever to hold it. Leave it overnight and check it in the morning. This is supposed to force any air up to the master cylinder.

[Rolland]

40 minutes ago, Michaelr11 said:

Try pumping up the front brake lever good and solid, then hold the lever and tie some string or rubber bands around the lever to hold it. Leave it overnight and check it in the morning. This is supposed to force any air up to the master cylinder.

 

Ok I will try that 

[dirtrider]

11 hours ago, Rolland said:

I have replaced all the rubber brake lines and new pads, got the rear brake working great good solid pedal this is on the R1100RSl. The front set I am having a little trouble, I have to pump the handle up a couple of times to get what I would be a solid feel on the brakes. I have bled them and am getting no air bubbles altho I think there must be in the system ,  Is there a trick to getting the front better. I did have good brakes prior to losing the front hose and some fluid.

 

Morning  Rolland

 

Have you ridden the motorcycle yet? If not and you have enough brake feel to ride it safely then do that. The ABS on your 1100 resets & calibrates the ABS displacement pistons on ride-off, not every time but it usually will when it hasn't been done in a while  (that is the "rr uu ppppp" sound you hear at ride-off from a stop. 

 

If you still have a soft hand lever after riding then____

 

You probably have a little air still trapped in the system, usually in the master cylinder, or the ABS pump, or in a caliper behind a piston.

 

First thing (easy thing) to try is to put the motorcycle on the center stand then turn the handlebars all the way right then lightly pump the hand leaver (only about 1" to 1-1/2", NO MORE than that). Slow lever movement, do not pull full stroke & do not pull until pressure is felt. 

 

Then turn the handlebars all the way left & do the same about 1" to 1-1/2' of lever movement. 

 

Then see what the brakes feel like-- doing the above can purge trapped air out of the end of the master cylinder bore back up into the fluid reservoir. 

 

If you still don't have a solid brake lever feel then pry both side front brake pads back away from the brake rotors then hold them there with shims or wedges. (cedar shingle wedges work, as well as thin pieces of wood or plastic). You don't need to hold the caliper pistons all way into their bores but hold them in far enough to decrease the fluid volume behind the pistons. 

 

Then rebleed the front calipers, if you get a little air out then you probably found your trapped air. If you don't get any air out then it is probably in another area. 

 

If the above doesn't help AND you have enough brake lever feel to ride the motorcycle, then do that as that can (usually will) dislodge any trapped or at least combine it in one or two locations. 

 

I seldom have to get this far in bleeding the 1100 brakes but have had to a few times when the brakes were not bled correctly by someone else then brought to me with a soft feeling brake pedal or lever. (usually from not bench bleeding the master cylinder properly before a full system bleeding)

 

I have had to ride the motorcycle on a loose substrate road (sand, gravel, dirt, etc) then brake the had enough to get the ABS system to kick in (this exercises the ABS motor, clutches, & pistons to dislodge any trapped air.   Then do a complete re-bleed including the ABS pump. 

 

Did you replace all the rubber brake hoses on the front?   If you didn't then some (or most of) that soft brake feel (air in the system feel) could be caused by the old rubber brake hoses swelling up under pressure (can feel just like air in the system).

 

 

[Jim Moore]

As DR said, I found that riding it fixed my seemingly incomplete bleed. 

[Rolland]

First off thanks for all the information, I managed to get things working. I went back and bled both front calipers and Dirtriders instruction. Still had what I deemed as a too soft brake lever so I pumped it up and tied the lever back and let it sit over night. Voila' I have brakes now.  So again thanks for the help.