Excess "Pull" in Front Brake Lever

[Chop96]

2010 R1200R with ABS and 10k miles. Last regular service performed at 7.5k by the dealer - brakes were bled.

Problem: Front brakes don't engage until well into the lever travel and it takes pulling the lever nearly all the way to the grip to get full braking power. I usually brake with first two fingers and with my last two fingers on the throttle, but now I can't pull the lever close enough for full braking (lever hits outer two fingers - caused an "oh $hit" moment on Saturday). No brake warning lights illuminated. Front fluid reservoir is full.

When I left the dealer after service, front brake lever was very firm with great engagement after just a little travel - in fact, first time I used the brakes, I didn't expect the short pull before engagement and inadvertently ended up grabbing pretty hard. While the pull has gotten progressively "longer" since the service, there was a sharp drop in performance on Saturday and it's now to the point where I really don't like it. I've got plenty of wear left in the front pads (just pulled off the retainer springs to check), but the lever feels like the pads are completely worn and need to be replaced.

It seems like the brakes need to be bled again, but I haven't noticed any leaking brake fluid (entry for air). I did some very aggressive riding (and braking) last Thursday during a cornering clinic, but there was no difference in braking from Thursday morning until Saturday after already riding 250 miles (200 then a 5 hour break, then started again). Not sure what could be wrong, but I'm going to try to get it into Morton's this Friday to get it checked out.

Any ideas out there as to what the issue could be or causing this degradation in braking performance? Anyone else experienced anything similar?

[deilenberger]

Similar.. yes. The pads are being knocked back from the rotors. It seems to happen more as the pads wear, although even with almost new ones (EBC HH's) - there is still a bit of this effect.

It's one of those "they all do it.." sort of things. Some worse then others.

You can change the lever position with the adjusting screw to move it away from the grip.. Yours sounds worse then mine ever has been.. I've had finger pinching like you describe, but I also have GripPuppies (foam grip covers) on my grips, which reduces the clearances.

Probably worth bleeding the brakes again, but I haven't found that a long term answer. Cleaning (toothbrush works) the exposed part of the caliper pistons (with pads out) - then pushing them back into the caliper, and finally reinstalling the pads and pumping the pistons back out with the brake lever seems to have the best effect on the travel.

FWIW - the pads are purposely moved back from the brake rotor so it doesn't overheat and you don't wear out pads too fast (wish they did this with the rear brake, but that's a slightly different issue..) It's done by rotor runout, and by the design of the caliper piston seals. Pushing the pistons back into the caliper seems to reset the seals. The seals are designed to allow free movement toward the rotor, and provide a slight retraction force when brake hydraulic pressure is released.

BTW - if you do go to push the pistons back into the caliper bores - you may need to lower your brake fluid level. If fluid was added, or it was topped off when they were bled last time, retracting the pistons may cause the fluid to be too high, which might cause a leak around the master cylinder cap.

[Chop96]

Well, I wasn't able to get into Morton's on a couple of days notice, but they gave me a suggestion over the phone for something to try... This:

Or you can use some electric tape to hold the lever squeezed in tight and leave it overnight to bleed the air, a trick an old dirt bike racer taught me.

Specifically, leave it on the side stand with the bars turned to the left full lock with the lever pulled all the way in (I used a long velcro strap). In the morning, gradually release then very slowly squeeze and release the lever a couple of times to help work any bubbles out of the master cylinder. Worked like a charm! Nice and firm now.

[Anyname]

I hate to ask the obvious, but have you checked the adjuster on the lever?

[Chop96]

I hate to ask the obvious, but have you checked the adjuster on the lever?

First thing I checked - no change in starting lever position. I could have moved the lever further out, but don't like the extra reach required.