"Soggy" rear brake pedal
- Thread starter Spud
- Start date
I have to pump my rear brake for it to work. I don't normally use the back brake, but when I do I find that I have to press the peddle several times. It has only started to happen since I put new pads in.
Just keep bleeding the brakes, i do mine every 3-6 months, front and rear. BTW my rear pads have lasted over 12,000 miles with plenty left
Did it on my Honda VFR and all the time on my Triumphs (with the Triumphs I used to have to crack the nut near the master cyclinder and then re-tighten). So not just BMW's
just one of those jobs to do, you don't need a fancy tools, patience, a tube and decent fluid.
Did it on my Honda VFR and all the time on my Triumphs (with the Triumphs I used to have to crack the nut near the master cyclinder and then re-tighten). So not just BMW's
just one of those jobs to do, you don't need a fancy tools, patience, a tube and decent fluid.
I had this on my 2016 GSA. It's a known fault and has got something to do with not using the rear brake (ie the rear brake is only operated by the front brake lever linked braking). BMW dealers will bleed the rear brake for you on request foc.
How is the air getting in? I have had this rear brake issue on both my LC GSs, if the brakes are bled by the dealer they are fine for only a short while before going back to 'normal' they don't get any worse after this. This is such a common issue I would have thought that some of the clever folk out there would have found the cause.
The dealer acknowledges it happens but can’t work out where the air is getting in - BMW aren’t letting on if they know.
I have this problem too. I adjusted the pedal to give ONLY 1mm clearance at the stop and this improved things for a while.
I’m going to follow the BMW procedure to replace the fluid in my front and rear brakes.
- push pads back, remove and hold the pistons back.
- suck out all the old fluid from the reservoir
- suck out old fluid from the line at the bleed nipple
- draw new fluid through from the reservoir at the bleed nipple till no bubbles are seen
- bleed using the old school method
- re-fit pads, pump to set and top up
This procedure is the same for each caliper but there is no mention of how this might affect the ABS pump. Anyone got a plumbing diagram?
I’m going to follow the BMW procedure to replace the fluid in my front and rear brakes.
- push pads back, remove and hold the pistons back.
- suck out all the old fluid from the reservoir
- suck out old fluid from the line at the bleed nipple
- draw new fluid through from the reservoir at the bleed nipple till no bubbles are seen
- bleed using the old school method
- re-fit pads, pump to set and top up
This procedure is the same for each caliper but there is no mention of how this might affect the ABS pump. Anyone got a plumbing diagram?
Oh the neck bone connected to the.....
Brain bone...
Further study of the BMW software results in...
Front brake master hose goes to the ABS pressure modulator (PM). A second hose goes from the PM to the t junction on the forks from where the lines go to each caliper.
Back brake master hose travels forwards to the PM and the the output hose comes all the way back to the cylinder. That’s a lot of hose!
The BMW drain and fill method makes sense to me now as it’s a good way to ensure the whole circuit is refreshed.
Brain bone...
Further study of the BMW software results in...
Front brake master hose goes to the ABS pressure modulator (PM). A second hose goes from the PM to the t junction on the forks from where the lines go to each caliper.
Back brake master hose travels forwards to the PM and the the output hose comes all the way back to the cylinder. That’s a lot of hose!
The BMW drain and fill method makes sense to me now as it’s a good way to ensure the whole circuit is refreshed.
OldSteve
Registered user
This thread seems to have morphed into one about bleeding brakes rather than excessive travel. My 1250GS has solid rear brake action, just a lot of dead travel in the pedal before anything happens so I think this is a different issue that bleeding won't help. I may be wrong and at the next service (whenever that might be now) I'll get the dealer to check the brakes and see what happens as it will be due a fluid change anyway.
There may be two issues, however I can state with absolute certainty that my current and previous 1200 GS TE both both suffered from air getting into the back brake circuit leading to excessive travel and spongy action. Each time my dealer bled the bakes to fix the issue lots of air came out. Rear brake would be fine after bleeding but would slowly deteriorate until same problem re-occurred after say 3000 miles, which is about 3-4 months of use for me.
(My reply below from a similar thread here).
Am experiencing same loss of rear brake pedal after repeated bleedings.
Put in a new master cylinder, same result.
Am currently trying out ATE200 high temp brake fluid.
I suspect it's a failure in the abs cum proportioning valve (ie the linked brakes). Try bleeding and then test riding using only the rear brake pedal, the brake will not deteriorate.
With bike on center stand, can you "induce" linking by braking the front and seeing whether the rear wheel is stopped? I can occasionally get this to happen, almost randomly, hence my guess about the failure of proportioning valving.
Nonetheless, am mystified as to where this air is getting into the system. Has there been any conclusions yet here?
Thanks
Am experiencing same loss of rear brake pedal after repeated bleedings.
Put in a new master cylinder, same result.
Am currently trying out ATE200 high temp brake fluid.
I suspect it's a failure in the abs cum proportioning valve (ie the linked brakes). Try bleeding and then test riding using only the rear brake pedal, the brake will not deteriorate.
With bike on center stand, can you "induce" linking by braking the front and seeing whether the rear wheel is stopped? I can occasionally get this to happen, almost randomly, hence my guess about the failure of proportioning valving.
Nonetheless, am mystified as to where this air is getting into the system. Has there been any conclusions yet here?
Thanks
Just suffered excessive sudden rear pedal movement , 2 months ( and 1,000 miles ) after dealer fluid change .
(My 2014GSA was also an mot failure , in 2019, for ‘excessive pedal travel / dangerous ‘)
Dealer, this August , ‘unable to help me for 6 weeks ‘ , despite them recently changing fluid and me having extended warranty and breakdown insurance
Dealer recommended “ activating ABS in case there is an air bubble” and commented that an ABS bleed is not routine at fluid change .
So, in desparation , bleeding done using GS-911 to activate ABS on two occasions , in between bleeds . Think now OK, but nevertheless a recurring problem
Seems a common problem
Sent from my iPhone using Tapatalk
(My 2014GSA was also an mot failure , in 2019, for ‘excessive pedal travel / dangerous ‘)
Dealer, this August , ‘unable to help me for 6 weeks ‘ , despite them recently changing fluid and me having extended warranty and breakdown insurance
Dealer recommended “ activating ABS in case there is an air bubble” and commented that an ABS bleed is not routine at fluid change .
So, in desparation , bleeding done using GS-911 to activate ABS on two occasions , in between bleeds . Think now OK, but nevertheless a recurring problem
Seems a common problem
Sent from my iPhone using Tapatalk
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