Rear brake pedal goes down too far.. bleeding?

Thats interesting.. will have a full read when I get time... does it have all the same stuff as the 911?... how do you connect?
 
beaver said:
Thats interesting.. will have a full read when I get time... does it have all the same stuff as the 911?... how do you connect?
Click to expand...

It doesn't have all of the GS911 but has some very useful functions. Requires an android phone for the ap. A bluetooth OBD tool and an adaptor cable. Lots of info on his website use google translate as website is in German, but the ap is free to try. (Need a paid version to make changes).
There is a video https://www.youtube.com/watch?v=3ET0FLheZTQ and ap is on google play https://play.google.com/store/apps/details?id=de.wgsoft.motoscan&hl=en_GB
 
My rear brake is the same. The pedal travel was improved after the 12k fluid change, but it soon became excessive again. It’ll still lock up momentarily if I stamp on it.

With regards to the rear disc getting hot, bear in mind that the brakes are linked, so the bike still applies the rear brake even if you never touch the pedal :thumby: It may be worth cleaning the pistons though if you think they’re sticking. It’s only a 5 minute job.
 
Excessive rear pedal travel developing between services is not unheard of on the LC GS - my last one did it and the dealer had no explanation as to what was causing it - after a service the pedal would be rock hard but would gradually soften over time until halfway between the service intervals the excessive travel had completely returned.
 
My 2016 had this problem. I reported it at first service and was told it was normal. Didn't report it at second service and was told they had fixed it (it was better for a while). The woman on service reception at NOG is so clueless I didn't bother to argue.
My 2017 has also developed excessive brake pedal travel. It is due for its annual service in a couple of weeks. Let's see if Bahnstormer can do any better.
 
My 2016 is the same - far too much travel on the rear pedal though pumping it does make it slightly better.
 
We'll, cracked the bleed nipple, fitted a pipe into my oil bowl.... 11mm ring on the nipple... 3 pumps, hold pedal down, reach over the bike and release some fluid. Lock off and release the pedal... Did this a few times and it felt better.. took filler top off and it was close to the bottom, so filled up beyond max. Did the same... May be 25 goes before it was low again.. topped up above max... And did the same until it hit max level... Final lock off and replaced filler top... Travel now 20mm so see how we go...
Also pushed the pistons in and out a few times to make sure they are free...
Easy to do.. 15 mins all in.. fingers crossed ��
 
beaver said:
We'll, cracked the bleed nipple, fitted a pipe into my oil bowl.... 11mm ring on the nipple... 3 pumps, hold pedal down, reach over the bike and release some fluid. Lock off and release the pedal... Did this a few times and it felt better.. took filler top off and it was close to the bottom, so filled up beyond max. Did the same... May be 25 goes before it was low again.. topped up above max... And did the same until it hit max level... Final lock off and replaced filler top... Travel now 20mm so see how we go...
Also pushed the pistons in and out a few times to make sure they are free...
Easy to do.. 15 mins all in.. fingers crossed ��
Click to expand...

20mm is what I have from first service
 
Altitude seems to be a factor, after an 11,000 ft pass in Colorado last summer I had no rear brake at all. All the dealer did was bleed it and has been fine since.
 
some 1 in 3's around... but not mountains :)
 
OK do not shoot me down to fast, I am just wondering if these 2 problems are possibly linked, failing brakes and the excessive heat rising from the exhaust, boiling the master cylinder hence the brake fluid going like water quickly, because if you look at the design of this little bracket that I got today, even though I have no problems yet, it might just be that directing the hot air away from the master cylinder helps in the long run, first picture shows heat being pushed back, as bracket is installed, and second picture with no bracket shows heat going up, so on pretty hot days, this must certainly be useful even for that.

https://www.ukgser.com/forums/showt...-getting-cooked/page21?highlight=exhaust+heat



bildhochladen
 
I think if you were seeing temps that would be detrimental to the brake fluid, you'd be melting the plastic container also.
Not sure how hot it gets in the brake caliper itself, but must be way above what it would see here I'd guess?

Boiling point
................Dry boiling point.......Wet boiling point
DOT 4........230 °C (446 °F)........155 °C (311 °F)
LHM+ ........249 °C (480 °F)........249 °C (480 °F)
DOT 5........260 °C (500 °F)........180 °C (356 °F)
DOT 5.1.....260 °C (500 °F).........180 °C (356 °F)

The Dry Boiling Point of brake fluid refers to the boiling temperature of fresh, new brake fluid from an unopened container. Whereas the Wet Boiling Point is defined as the temperature DOT brake fluid will begin to boil after it has absorbed 3.7% water by volume. DOT brake fluid will reach this level of water volume after roughly 2 years of service, which is why it is advisable to renew your brake fluid every 1-2 years.

Do we use DOT5 in our bikes??
 
beaver said:
I think if you were seeing temps that would be detrimental to the brake fluid, you'd be melting the plastic container also.
Not sure how hot it gets in the brake caliper itself, but must be way above what it would see here I'd guess?

Boiling point
................Dry boiling point.......Wet boiling point
DOT 4........230 °C (446 °F)........155 °C (311 °F)
LHM+ ........249 °C (480 °F)........249 °C (480 °F)
DOT 5........260 °C (500 °F)........180 °C (356 °F)
DOT 5.1.....260 °C (500 °F).........180 °C (356 °F)

The Dry Boiling Point of brake fluid refers to the boiling temperature of fresh, new brake fluid from an unopened container. Whereas the Wet Boiling Point is defined as the temperature DOT brake fluid will begin to boil after it has absorbed 3.7% water by volume. DOT brake fluid will reach this level of water volume after roughly 2 years of service, which is why it is advisable to renew your brake fluid every 1-2 years.

Do we use DOT5 in our bikes??
Click to expand...

I see your point beaver, but my thinking was, given some of the ops are getting excessive heat from their exhausts, not sure what the temps are, it would be keeping the fluid warm all the time giving it no time to cool down, no cool air flowing through, maybe, I am totally wrong but was just a thought.
 
Just use oil in the system.. it will not boil or go off over time as it won't absorb water... mind you, any water getting into the system would pool and not be taken up by the fluid, making the wet boiling point of the system 100 deg c.. so maybe not the best idea :)
Do you think keeping the brake fluid warm / hot is an advantage or disadvantage.. if the water could get back out, it may help reduce the water content.. on the other hand, it may just cause condensation to form, adding more water to the system. I think the cycle of hot to cold could have the effect of drawing more in. Maybe that's whats happening to our brake fluid over time?
 
Moisture in the brake fluid can cause soft brakes when in heavy use due to the water vaporising to gas due to the heat, making the contents of the brake line compressible, which won't be the case while the water is in liquid form.

However, I think a common problem with the GS is a soft rear brake pedal even when the brakes are cold. This seems to be due to some sort of problem, possibly related to the ABS plumbing, that lets air into the system. I had this with my 1200GS, and it only improved for a while after the dealer bled the brakes under warranty. It also improved after the scheduled brake fluid replacement. So far, after 2500 miles the 1250 still seems OK.
 
Nippy Normans supply Touratech, Wunderlich, Desert Fox and many other makes of accessories.
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