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#991019 - 07/01/17 05:00 AM Lower front brake hose burst - R1100RT  
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Reecehk Offline
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Reecehk  Offline
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South Australia
I just got all the new rotors and pads installed, I pulled the brake lever and it went all the way down to the hand grip!!
I pumped it up but with steady pressure just kept moving down to the grip.
I then discovered that the wheel was jammed tight, I could barely move it then suddenly the LH lower brake hose swelled and burst!! confused
Now I am in a fix, I assume I'll now have to replace the lower 2 hoses (minimum) and bleed the brakes.
But what caused the pressure build up and the wheel to lock up?
If I repair it what's to stop it from happening again? Where did I go wrong?
Please Help! dontknow

I just had a horrible thought, it's ABS, I probably should have had the bike running, the manual never mentioned anything. Could there be any damage to the, I assume, power assistance??

#991024 - 07/01/17 10:26 AM Re: Lower front brake hose burst - R1100RT [Re: Reecehk]  
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eddd Offline
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eddd  Offline
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Most likely the inner lining of the hose deteriorated to the point where a piece of that lining got loose and acted like a one way valve. Pressure was built up as you pumped the brakes, but it was unable to return to normal.

The fact that the hose burst is a clear indication that the integrity of the hose had been compromised allowing fluid to leak passed the inner lining and rupture the outer covering. I'm guessing the hose(s) were in a weaken condition prior to you working on the rotors, and removing the calipers was enough to cause the problem.



12 Kawasaki EX650
13 Yamaha XT250
16 KTM RC 390
96 R1100RT - forced retirement at 175,000

#991025 - 07/01/17 10:30 AM Re: Lower front brake hose burst - R1100RT [Re: Reecehk]  
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dirtrider Offline
The Oracle
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Ohio
Originally Posted By: Reecehk
I just got all the new rotors and pads installed, I pulled the brake lever and it went all the way down to the hand grip!!
I pumped it up but with steady pressure just kept moving down to the grip.
I then discovered that the wheel was jammed tight, I could barely move it then suddenly the LH lower brake hose swelled and burst!! confused
Now I am in a fix, I assume I'll now have to replace the lower 2 hoses (minimum) and bleed the brakes.
But what caused the pressure build up and the wheel to lock up?
If I repair it what's to stop it from happening again? Where did I go wrong?
Please Help! dontknow

I just had a horrible thought, it's ABS, I probably should have had the bike running, the manual never mentioned anything. Could there be any damage to the, I assume, power assistance??


Morning Reecehk

Difficult to tell what happened from here but it might be as simple as the hose that burst had the inner liner break or split then act like a check valve as the hydraulic pressure got behind the lining & ballooned it into the fluid passageway.

It doesn't sound an ABS controller problem but nothing is assured.

Did the front wheel unlock after the hose burst? If so then it was more that likely that hose inner liner causing the lock-up or possibly the master cylinder take-up port plugged then trapped pressure in the line. (small hole in bottom of master cylinder reservoir)-- If this hole is plugged, or the master cylinder piston isn't returning far enough to uncover that hole, then you probably won't be able to bleed the front brakes.

If you get good fresh brake hoses on that bike (all the hoses as they are probably all in the same condition) then you shouldn't be able to break or fail a hose just by pulling on the brake lever.


D.R. ___
Sent from my rotory dial wall phone!
#991026 - 07/01/17 10:31 AM Re: Lower front brake hose burst - R1100RT [Re: Reecehk]  
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szurszewski Offline
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Portland, OR
Sorry to hear that, but very glad it happened in the garage, so to speak, and not out on the road.

Are these the original brake lines? If so, it's not a surprise that it burst - more of a surprise that it lasted this long.

It's possible that the lines were coming apart internally and you had a piece of line lodge somewhere preventing fluid from moving back away from the caliper, and then you pushed more down and it was too much for the lines.

Having installed new pads/rotors means you must have pushed the caliper pistons well back into the calipers, so it's normal that your lever was able to go all the way to the bar. That said, I'm always careful in that situation to gently work the lever less than the full travel - I'm no expert but I've been told that pulling it all the way will move the piston in the master cylinder further than it normally goes, which puts into territory that could have crystallized fluid/crud build up that might damage the seals up there.

When you did the pads/rotors, did you also bleed the brake circuits?

When you say you should have had the bike running, are we talking about an 1100? I am maybe mixing years up, but I thought that meant you would have non-servo brakes so it would not matter if the bike was running.

I'm sure you'll get better answers soon - good luck!
josh


EDIT: I type slowly - you ALREADY have better answers smile

Last edited by szurszewski; 07/01/17 10:32 AM.

*insert witty remark here*
#991027 - 07/01/17 11:26 AM Re: Lower front brake hose burst - R1100RT [Re: szurszewski]  
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Reecehk Offline
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Reecehk  Offline
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South Australia
The bike is a 1998 R1100RT, All I did was to install the rotors and new pads, I was avoiding having to bleed it, was going to take it to a BMW mechanic. The brake lines are likely the originals.
Problem is the mechanic is over 200Kms away, I don't have much choice other than doing the job myself.
Once I get the tupperware off is it easy enough to get the hoses off without taking the petrol tank off?
I assume I am to replace the 4 hoses, anything else?
What's the easiest way to drain the existing fluid?
Is there a simple method of bleeding the brakes? I don't have any bleeding tools other than normal spanners etc.
Sorry about all the questions but I have never done this before only on an old car with drum brakes!! ohboy

#991030 - 07/01/17 11:42 AM Re: Lower front brake hose burst - R1100RT [Re: Reecehk]  
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Ozzyal Offline
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Ozzyal  Offline
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Victoria Australia
I just put new brake rotors on my old CBR1000F and replaced the hoses with braided line at the same time . Its not a hard job , though I'd be surprised if you can do it without removing some of the bodywork on the Beemer . I bought a vacuum bleeder but I already have an air compressor . I believe that you can buy a hand vacuum bleeder .
I'll be changing the lines on my R1100RT soon to I think . It isn't very expensive to change them to braided line and the factory recommendation is replacement each five years I think .

#991032 - 07/01/17 12:19 PM Re: Lower front brake hose burst - R1100RT [Re: Reecehk]  
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dirtrider Offline
The Oracle
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Morning Reecehk

I was avoiding having to bleed it, was going to take it to a BMW mechanic. The brake lines are likely the originals.--You will definitely have to bleed it now as the fluid is gone & the new hoses will be full of air.

Problem is the mechanic is over 200Kms away, I don't have much choice other than doing the job myself.
Once I get the tupperware off is it easy enough to get the hoses off without taking the petrol tank off?
I assume I am to replace the 4 hoses, anything else?
--This kind of depends on what or how much you replace. You might look into a brake line replacement kit.

What's the easiest way to drain the existing fluid?--The front sounds like it is already drained (just put a hose on the bleeders screws then run that hose into a bottle or jar then open the bleeder screw & let the fluid run into the container. (just be VERY careful to not get any brake fluid on the bike's plastic, paint, or dash plastic as brake fluid will remove paint & ruin plastic)

Is there a simple method of bleeding the brakes? I don't have any bleeding tools other than normal spanners etc.
Sorry about all the questions but I have never done this before only on an old car with drum brakes!!
--With all the air you will have in it you will probably have to remove the fuel tank & bleed the ABS controller bleed fittings. BUT__ if you don't want to remove the fuel tank then you can just bleed from the master cylinder to the caliper bleed fitting as that will get most of the air out of the system (enough to ride the bike). Then you should be able to ride it to a repair facility for a full system bleeding.

Do you have any way to trailer the bike to the BMW mechanic? If so then the BMW mechanic can install the hoses & fully bleed the brakes.


D.R. ___
Sent from my rotory dial wall phone!
#991033 - 07/01/17 01:07 PM Re: Lower front brake hose burst - R1100RT [Re: dirtrider]  
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Reecehk Offline
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Reecehk  Offline
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South Australia
This is turning into a nightmare!! It's winter here so getting it to the mechanic is going to be even more painful.
Maybe I will have to take the tank off, would be a good time to change the petrol filter!!
If I go ahead and take the petrol tank off is there a method that you could point to or do you know what is to be done?
The stupid manual says if it gets air trapped in the modulator then you have to take it to a BMW dealer!!

Edit: Does bleeding at the ABS under the tank mean the rear caliper has to be bled as well? I have no info on this, I was going to leave the rear for the mechanic to do later.

#991035 - 07/01/17 01:34 PM Re: Lower front brake hose burst - R1100RT [Re: Reecehk]  
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szurszewski Offline
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I would suggest as above that you purchase a kit of stainless brake lines - here in the US that is generally cheaper than buying the factory lines and they should last longer. In any case, you're going to need to replace the burst line (and if that one burst...well, the others are probably in the same shape - you really don't want one to rupture while you're on the road!).

If you are ok removing the body work, removing the tank is really not any harder - you will need to disconnect the fuel lines (mark them so you can put them back together the same way) and the electrical plugs, but it's really way less work than removing all the body screws was - not complicated.

You *can* actually get to the abs bleed ports by just lifting the rear portion of the tank (once the body work is removed) and blocking it up a few inches, but as you said you might as well replace the fuel filter while you're in there if it's due, or if you don't know when it was last done.

Here's a vid for you - I confess that I haven't watched it as our motel internet is very slow, but check it out. I did the lines on our K1200LT at the beginning of this trip in a friend's garage with only the instructions in the brake line kit package (and they really just said, remove this line, replace it with this one... and repeated that for each line). It took me a handful of hours, but mosty that was removing and replacing a lot of body work.

https://www.youtube.com/watch?v=3qDYjAfwow8

You can do it - good luck!

Oh - you can manually bleed the brakes by hand. Just make a container from an old water bottle, put a hole in the lid to fit in some tubing that is sized to fit the bleeder. Helps to have someone to open/close the bleed valve, but if you put enough fluid in the container so you can't suck air back into the caliper you can use it as a one man bleeder. Just remember that after you have it bled and closed off, gently pump the brake lever (not full travel!) to get the pistons moved back into place before you try to ride the thing.

josh

edit: here's a DIY brake bleeder on youtube

https://www.youtube.com/watch?v=1wwq1Vlk4Wg

Last edited by szurszewski; 07/01/17 01:38 PM.

*insert witty remark here*
#991038 - 07/01/17 01:44 PM Re: Lower front brake hose burst - R1100RT [Re: Reecehk]  
Joined: Jun 2010
Posts: 13,194
dirtrider Offline
The Oracle
dirtrider  Offline
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Ohio
Morning Reecehk


Maybe I will have to take the tank off, would be a good time to change the petrol filter!!
If I go ahead and take the petrol tank off is there a method that you could point to or do you know what is to be done?
--Taking the tank off can be a challenge on the BMW 1100 as the 1100 didn't come with quick disconnects. (hopeful someone has added them in past as that makes tank removal easier)-- You C-A-N get to the ABS controller bleed screws by just lifting the rear of the tank up & propping it up while you work. Not easy to work but possible.

The stupid manual says if it gets air trapped in the modulator then you have to take it to a BMW dealer!!--No, you don't have to take it to a dealer. The dealer can run some bleeding tests & functions that you can't easily do at home but basically you CAN bleed & get the air out at home without dealer assistance.

Edit: Does bleeding at the ABS under the tank mean the rear caliper has to be bled as well? I have no info on this, I was going to leave the rear for the mechanic to do later. --No, on the BMW 1100 brake system you can do only one end. BUT!-- if you remove the tank, have all the bleeding equipment out & handy then might as well go ahead the do the rears also. (rear is easier than the front & you really SHOULD replace the rear rubber brake hose at this time as it probably isn't far behind the front hose on failure.

(IF)- you are planning on having a mechanic do the rear then you can probably do the front without bleeding the ABS controller bleeders or removing the fuel tank. You probably won't get ALL the air out of the front without bleeding at the ABS controller but you should be able to get enough out to easily ride the bike to the BMW mechanic.


D.R. ___
Sent from my rotory dial wall phone!
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