Lost Rear Brakes Today on 2000 RT

[Theophilus]

I did not want to hijack ETZ's "very weak rear brakes" post, though my problem may be similar enough to just refer me there. If so, someone just say so.

 

On the other hand, ETZ's problem sounds like one that came on gradually. My rear brake was fine yesterday, but noticeably weird this morning on the way to work. This evening, once home, the brake could barely keep me from rolling the bike with my left foot (on pavement) with the rear brake depressed as hard as I could with my right foot. I noticed that the pedal goes down (even) further than usual. It also rests lower than usual without being pressed. I have to actuate my ankle further than usual to reach the pedal at all. When depressed, the pedal seems to reach end-of-travel - either for the lever or for my ankle(!) - fairly quickly. The rear brake is useless at the moment.

 

I typically use the rear brake for all braking, favoring the front brake. When using the rear to smoothe out power application in very low speed curves or when using the brake to hold me against a light slope at a stop sign/light, I use only the rear brake.

 

I am (or had been) planning a day trip in 5 days. So would anyone like to advance:

 

1. Best guesses at what is wrong?

2. Advice on whether to make trip on front brakes only?

[flat_twin]

The pedal itself is lower than normal? Have you checked to see that the pedal assembly is bolted up tight? Mine came loose one day and felt kinda weird just before the bolt fell out and there was nothing for the linkage to push against.

If the pedal assembly is tight and you've got enough fluid in the reservoir, the master cylinder might be bad.

I would NOT take a trip with the rear brakes as you describe.

You should be able to get it repaired in five days and enjoy your trip.

[Theophilus]

You should be able to get it repaired in five days and enjoy your trip.

 

F_T - thank you for the thought. Yes, the pedal is lower than usual; I am 90% certain in saying this. If it is just dinking with a bolt that I can easily reach, then it may be do-able, but if we are talking about dealer service, your experience is far different than mine to suggest a 5-day turnaround...

 

Not to mention the fact that I cannot take it to a dealer until the morning I was planning to leave on the trip...

[Tony_K]

Ok I am tearing into my rear tomorrow night before leaving for Torrey

 

I have a draging piston. The front one of the two in the rear is going out but not easily returning to release pressure on the disc.

I found this after switching out to new brake lines.

 

Your pedal could be low because your shoes are worn beyond spec. Very easy to let happen. Your adjustment at the piston rod could be out of whack. You can readjust this so easily it's laughable.

Worst case thing is air in the ABS due to too low a fluid in the res. Ugh this sucks. I got air into mine with the in the line change. You have to bleed the ABS to resolve this.

 

Check your pads and fluid reserve first. Adjust the rod second, if there is enough pad and fluid left.

If that dosen't fix it...ABS bleed may be in order!

 

If your not currently intimate with your bikes workings the ABS bleed will make you so!!!!

[bluedawg]

Check the caliper bolts also. I saw one once where one bolt had worked its way out allowing the caliper to rotate around the remainin bolt.

Also check the fluid level in your rear master cyl.

If it's low (and it's not leaking), your pads are probably worn down.

Don't leave home without your rear brake.

Good Luck

Mike Canant

Albuquerque

[NoLongeraK1200RSRider]

Theo.. why on earth do you "use the rear brake favoring the front?" Am I misreading this or?? The FRONT has way more stopping power than the rear due to several things that occur during braking. Also, that would most likely be the reason most high performance bikes have 2 disks on the front. JMHO and am truly curious.

[Theophilus]

OMK12RSR -- Yes I believe you have misunderstood my meaning. It was not well expressed, despite my best effort. "...favoring the front" means that I use the front brake for the lion's share of the work. I use the rear in almost all of my braking actions, but the front is always the main player, except in the two cases outlined. Sorry not to have been clearer.

[Theophilus]

<snip> Your pedal could be low because your shoes are worn beyond spec. Very easy to let happen. Your adjustment at the piston rod could be out of whack. You can readjust this so easily it's laughable.

Worst case thing is air in the ABS due to too low a fluid in the res. Ugh this sucks. I got air into mine with the in the line change. You have to bleed the ABS to resolve this.

 

<snip>

 

Tony, thank you for the tips. I need to look at the bike. If it is any worse than a linkage adjustment, it will have to wait and probably be done at the dealer. The brake system is not where I intended to get my wrenching start, and I am working very long hours at the moment.

 

If it were air in the system or worn pads, wouldn't the problem have come on gradually? Wouldn't the symptoms make more likely a rod/linkage problem, or a loose caliper assembly as mentioned by bluedawg?

 

 

[Tony_K]

Air in the system would yeild no petal right quick.

Worn pads would be a slow curve. Loose parts a quicker slow curve.

Air is the quickest, resulting in a petal symptom just as you described.

You need to do a visual and physical inspection of all related parts in the system.

 

If air is in the system pumping the pedal several times will compress the air resulting in a pedal firmness increase. If this builds the pedal you for sure have air in the ABS.

[Theophilus]

I have just gone out and done a visual, and I think this may be related to another issue I have been noticing for some time(?)

 

The strut that runs from the rear drive to a point near the vertical bar of the brake pedal linkage has its forward-end bolt covered in what I fear may be brake fluid, and this has run onto the catalytic converter as well. I have been smelling fluid on the cat for some time, but thought it was tranny fluid overflow from a sloppy job at the dealer last time in. It was tranny fluid at one time, but I cleaned that up, and I think this is something else. At the same dealer trip at which the tranny fluid was replaced, there was also a rear and front brake flush. I wonder if they botched it....

 

Anyhow, the pedal position looks correct, and the spring is intact, so I think my contention that the pedal position is low was incorrect; there just isn't any pickup in load until the pedal is fully depressed. I haven't checked the fluid reservoir; am I right in inferring from what I see that I can't properly get to the reservoir w/o removing tupperware? Or do I just need really small fingers?

 

Self-diagnosis: Pinhole fluid leak from rear brake system for some time that today decided to become larger and drain my system. Thoughts?

[Tony_K]

Self-diagnosis: Pinhole fluid leak from rear brake system for some time that today decided to become larger and drain my system. Thoughts?

 

To see the reservoir the only piece to remove is the black D shaped cover.

If you do have a leak and have drained the res and are unwilling or unable to do the work yourself be prepared for at least 4+ hours labor at dealer.

 

Anytime you see leaking fluids of any kind it is imperative to diagnos and identify what it is and where it is coming from ASAP.

 

I feel for you as you will have quite a repair bill coming your way if it is what you think. One I know I couldn't afford.

 

If it can be traced to dealer repair error in anyway during the flush you may be saved! Take in the work order and hopefully it's a loose connection .That wouldn't be good at all but at least it may be a faulty repair.

 

Remove the D cover and look very closely while depressing the brake hard looking for the leak. The actual piston is behind the foot plate so get a flashlight on there. The tell will show, hopefully in your favor.

[RFW]

One word.. air in the line. Ok, OK!....that's 4 words!

.

[Ken H.]

Disconnect the linkage and pull the boot back from it into the rear master cylinder. If you've got fluid in the boot, the master cylinder seal is gone. There is a rebuild kit for it. If it's dry, look elsewhere.

[NonComp]

Theo.. why on earth do you "use the rear brake favoring the front?" Am I misreading this or?? The FRONT has way more stopping power than the rear due to several things that occur during braking. Also, that would most likely be the reason most high performance bikes have 2 disks on the front. JMHO and am truly curious.

It is an interesting comment. As a new rider on an r1100, I am finding that I also use the rear brake more than the front, for the simple reason that the front is very sensitive. I really have to concentrate on applying pressure to the front so that I don't end up throwing my head forward all the time. When combined with the engine braking effect, which is considerable, it is hard to get a smooth deceleration. Another interesting note was that when I got the bike wih 58K miles on it, the front brakes looked like new, while the rear rotor was badly worn and needed replacement. So the previous owner used the rear quite a bit also.

[Tony_K]

the front brakes looked like new, while the rear rotor was badly worn and needed replacement. So the previous owner used the rear quite a bit also.

 

Nope, I bet the PO didn't use it as much as you think. The rear is a nororious for dragging. Gunk, rust and such cause this and it's often attributed to infrequent use!

[Bill_Walker]

Ok I am tearing into my rear tomorrow night before leaving for Torrey

 

That sounds really painful! Perhaps you should consult a specialist.

[Tony_K]

Ok I am tearing into my rear tomorrow night before leaving for Torrey

 

That sounds really painful! Perhaps you should consult a specialist.

 

whoops. That does look terribly bad in written word dosen't it.... ok back to your regularly scheduled programming.

 

I took everything apart last night no damage to dragging piston. Still drags.

Rear brake is all wacked out, guess I wont be using it much.

[russell_bynum]

Ok I am tearing into my rear tomorrow night before leaving for Torrey

 

That sounds really painful! Perhaps you should consult a specialist.

 

whoops. That does look terribly bad in written word dosen't it.... ok back to your regularly scheduled programming.

 

I took everything apart last night no damage to dragging piston. Still drags.

Rear brake is all wacked out, guess I wont be using it much.

 

FWIW, I always had odd pad wear on that rear brake.

[Theophilus]

Thank you for all the advice. The PO (who has also become a good friend) came over and showed me how to bleed the brakes. We could not find a leak, and the reservoir had fluid in it. We flushed at the caliper and found air bubbles during that flush. That explains the problem with the brake. We then flushed at the ABS, which apparently had not been done in a while, judging by the much darker fluid present right at the nipple, as compared to that at the caliper.

 

Well, then, you might ask, what about all that fluid that was leaking around? If it wasn't brake fluid, what was it? That is a tale for another post having nothing to do with brakes, sadly. I think I will title it "Swingarm Stealth Leak." Stay tuned...

[Tony_K]

Good, I am happy to see you did it yourself! It's not difficult, just time consuming thus expensive when done by paid professionals.

 

I will await your next tale into the world of oilhead wrenching.