Locked up front brakes 2001 1150 GS

[rkitts119722]

Help, I noticed my front brakes tended drag when stopped at a light. So I pulled the master cylinder cover and slowly squeezed the brake handle to maybe back some fluid out of the lines and let the pads back off of the disc. WRONG! The opposite happened! The front brakes locked up tight. I front wheel wouldn't budge. I opened the bleed screw. The brakes backed off a little. The wheel would spin once before coming to a halt. I closed everything back up. Gave the brakes a squeeze, and the brake locked up tight and would not release. I have repeated the process a few times with the same results. The pads do not want to back out from the disk!! I have the big Clymer manual but it doesn't discuss this problem. Thanks, Rick

 

[BC1100S]

Sounds like you need a full rebuild of your brake system. Let me venture a guess...original brake lines still on it?

 

[69zeff65]

Lucky you discovered this at a stop!

If you have the original rubber brake lines plan on replacing them with some good quality stainless brake lines, there are a number of sources out there.If your brakes haven't had a regular service (fluid change and bleeding) then you may have bigger issues with individual components. Brakes are not the component to cheap out on or attempt a "do it yourself" repair if you are not comfortable or lack tools and knowledge.

Start with research on brake service history on the bike and go from there.

 

[cycleman2]

When you have the cover off the master cylinder, it should squirt some break fluid when you pull the lever. The small hole in the bottom of the master cylinder could be plugged, not allowing the caliper pistons to return to resting position.

Bleed the brakes, but not sure or which procedure you should follow if yours had the servo system or the same abs system as on the 1100's. Some or maybe all of the 1150's had servo brakes, not sure about the GS. Somebody will chime in soon.

 

[69zeff65]

My '00 had non servo

My 2000 GS had the non servo brakes, 03 GSA had the servo the way to tell for me was the distinct klunck curchunk noise when you first take off after start up. Of course the servo brakes have the whizzy whiney noise when the brakes are applied. I think the servo brakes were a one or two year run from 'late 03 to 05 and then dropped. They work good if they are maintained properly.

 

[pglaves]

Brakes locking up are usually caused by one of three things: all of which prevent the fluid from freely returning to the master cylinder reservoir. 1. Collapsing lining in the rubber brake line. Pressure will push it through to the wheel but might not let it return. 2. A clog in the hole in the bottom of the master cylinder rewervoir may prevent the fluid from returning. 3. The piston in the master cylinder not fully returning blocks the return passage to the reservoir. This is usally due to a cruddy lever/lever pivot.

 

[rkitts119722]

Thanks to all

Thanks to all of you that chimed in with suggestions! The 2001 had the Brembo calipers and not the EVO system. Tomorrow I will have it and I'll post what happens. Thanks again, Rick

 

[happy wanderer]

Paul Glaves outlined the 3 possibilities above. If your bike still has the OEM rubber brake lines on it my money would be on his first suggestion which is failure of the inner lining of the brake lines which causes blockages. Brakes that won't release are the classic symptom of this.

Reports of failed OEM rubber brake lines on oilheads have been posted here for years now. Bottom line is if you have an oilhead of any year you should replace them. This is a critical safety item. I would not bother trying to bleed them. How would that work with brakes that lock up at every squeeze anyway? If your lines are rubber just go to Speigler.com and order new ones. Make sure you bleed the system out really well once they are installed to flush out any old rubber crud that may be lurking in the calipers etc.

No idea why so many cars and trucks go years and years and years without ever having to worry about brake lines but my guess is whatever material was used on the oilhead brake lines seems to have been chosen on price on not quality. And that was a terrible decision IMO.

 

[BMUUsed]

Same thing happened with the right front caliper on my 97 R1100rt after I installed new pads earlier this year. Got it back to the shop to try bleeding the brakes again, nothing came out. Pulled the banjo bolt off the brake line and chunks of rubber fell out. New lines fixed the problem.

 

[69zeff65]

First hand adventure for me

When those rubber lines get plugged up two things happen, the brakes don't release and the brake fluid heats up. When the brake fluid heats up it expands and applies more pressure to the brakes and will cause them to lock up. I know from personal experience with a '94 RS that I rehabbed a few years back. First test ride after I got it running, quick test ride on my street, turned into my driveway and the front wheel locked up and slid out. Lucky me the bike had no bodywork other than the gas tank and that didn't get touched, I had a good amount of bleeding from my shins that got caught up in the pegs.

The only way I got the bike to move from there was to completely remove the bleeders release the pressure.

 

[gsaddict]

Common issue with the old rubber lines. It will cause ABS modulator failures as well. Be sure to flush the entire system thru after replacing the lines

 

[henzilla]

No idea why so many cars and trucks go years and years and years without ever having to worry about brake lines but my guess is whatever material was used on the oilhead brake lines seems to have been chosen on price on not quality. And that was a terrible decision IMO.

Seems same line of thought about bio-degradable insulation and wiring looms on same generation of bikes...must be good intentions turn into future headaches as it has been mentioned "done to meet Germany's TUV regulations" or something close. The rubber lines were designed to break down after (insert#)years

 

[junkjohn]

Caliper piston could also be hanging up because of corrosion and debris.

 

[gsaddict]

Caliper piston could also be hanging up because of corrosion and debris.

bet not in this case

 

[rkitts119722]

Thanks again and again

This forum has been incredibly helpful and I really appreciate everyone taking time to help me out. I was heading to the dealer for tires anyway so after much trial and error with the brakes I had the dealer come and picked it up. Upon testing they said one of the lines ruptured!! So, from here on out I will be very diligent about brake maintenance! Thanks again. If I get it back on Thursday I still may make it to the rally!! Hope to see some of you there. Rick

 

[lowndes]

SAME problem with my '99 R1100S a month ago.

Hey, rkitts119722,

Recently I had a partial front brake seizure on my '99 R1100S ABS with 11k miles, on a day ride. I noticed the bike was extremely hard to push even a few feet on level concrete. On arrival back home and several hours of head scratching and wrenching, the problem was discovered in the small passages inside the left front Brembo caliper: there was substantial ground up, decomposing black rubber crud clogging the passage between halves of the caliper. This prevented the pistons there from retracting. Fortunately, it did not hold ALL the pressure, just enough to make the brake drag. The only place this rubber could have come from is decomposing OEM brake lines. Everything else in the system, seals, pistons, was pristine. I have pics of all this.

A retired motorcycle mechanic (Honda, Triumph, BSA) said this is a very common problem on most all bikes at 8-10 years. DOT4 is very aggressive chemically, eats paint, plastic, and stock brake lines are a synthetic rubber (plastic).

I learned a bunch.

Drop a quarter in each handlebar reservoir and leave it. This is the cheapest part you will ever "buy" for a BMW, and will prevent squirting brake fluid all over your bike. Ask me how I know.

Use some plumbing thread tape on the bleed nipples. They WILL leak around the threads when partially open, either pushing or pulling (bleeding) the brakes. You don't want either.

I replaced ALL flexible lines on the bike with PTFE (teflon) lined AN3 braided lines (Spiegler), front and rear brakes, and clutch. They are all the same age and have been maintained well and used DOT4.

When you bleed or try to change the brake fluid in the brakes or clutch, you DO NOT replace ALL the fluid in the system. Any fluid in the slave (caliper) cylinders is on a "dead end" in the system and will NOT be flushed no matter how much you pump thru there. This can be minimized by using a VACUUM system in stead of a "pressure", as in handle bar lever/master cylinder pumping action. You can push the new fluid thru, or pull it thru with a vacuum type device. With a vacuum device, you will be pulling all the caliper pistons into the fully retracted position and REMOVING as much of the old fluid as possible.

While doing this, you can visually verify that all pistons are FULLY retracting and operating properly by sighting along the surface of the disc at the pads with a small light.