R1100GS Front Master Cylinder

[MotoCammy]

Evening folks,

Looking for some advice, about 4 months ago I rebuilt the front master cylinder as it was leaking quite badly. I did notice some scoring on the bore and did my best to hone this carefully with some fine emery cloth and when I put it all back together it was sorted. However it’s started to leak again and I suspect that it again needs to be rebuilt.

My question is, is it just a case of a new master cylinder at this point? If so, does anyone know if there are alternatives to the original R1100GS one which would work since one from motorworks is going upwards of £300 quid…?

Some photos of the scoring below.

Cheers

 

[Riceburner]

Tbh, i don't mess about with trying to bodge brakes, get a new replacement.

Its your life.

 

[Paradiso]

I had the same experience as you. Rebuilt master cylinder, it seemed OK for a while, then started to leak. I bought a new master cylinder. I'm not aware of any alternatives. It's all integrated into the bars and controls. Ridiculous price when I can buy a new Yamaha master cylinder from China for not much more than a fiver.

Sent from my SM-S901B using Tapatalk

 

[Udders]

Never skimp on brakes and tyres! Always buy the best you can afford.

 

[chopper_harris]

Which grade of emery cloth did you use ?
Emery typically has a grit from 40-200 ish.

You could try carefully repeating the process with 1000 wet and dry, wrapped around a dowel and used wet with a soap solution.

As above, these are precision components - if you have gouged the bore, the new mid and end rubbers may be unable to create an effective seal.

 

[chopper_harris]

Checking the parts fiche, the front m/cyl unit for the R1100GS is common to all the R and K bikes from 1989 to 2001 ish.

You may find a decent pre-loved part from a reputable seller - eBay Germany is likely to have a better selection.

BMW Motorcycle Parts | Search for parts

MAX BMW Motorcycles offers an extensive BMW Motorcycle Parts fiche. OEM BMW Motorcycle Parts and Accessores can be ordered online for fast delivery. View our detailed BMW Motorcycle Parts diagrams and locate the part that you need efficiently.

shop.maxbmw.com

 

[MotoCammy]

I’ve ordered a new one…

I tell you, a late twin cam oilhead 1200 is getting more tempting…

 

[Wrigsby1]

I’ve ordered a new one…

I tell you, a late twin cam oilhead 1200 is getting more tempting…

I was having a clear up the other day and realised that I had spent at least £1500 on my £2k 90k miles + R11GS... Admittedly £800 was new front and rear shocks and included tyres and injector upgrade but TBH, even with the odd service, fix, tidy still to do, I'm glad I did...
Later bikes are better in so many departments but that "better" doesn't always mean the "quality" of the experience is much better...
I've had 5x R11Gss and I have finally realised why I keep coming back for more... Or is that more punishment...

PS .. just noticed yr Aberdeen... I live north and work in Aberdeen... There's even a bit of a custom GS appearing in the next door carpark which is great... mines out as an all year runner with condition to match...

 

[MotoCammy]

I was having a clear up the other day and realised that I had spent at least £1500 on my £2k 90k miles + R11GS... Admittedly £800 was new front and rear shocks and included tyres and injector upgrade but TBH, even with the odd service, fix, tidy still to do, I'm glad I did...
Later bikes are better in so many departments but that "better" doesn't always mean the "quality" of the experience is much better...
I've had 5x R11Gss and I have finally realised why I keep coming back for more... Or is that more punishment...

PS .. just noticed yr Aberdeen... I live north and work in Aberdeen... There's even a bit of a custom GS appearing in the next door carpark which is great... mines out as an all year runner with condition to match...

Well got round to fitting the new master cylinder today and feeling much more confident in the brakes.

I’m in a similar boat, my 3k R1100 has probably had about 2k worth of parts put in this year and I keep thinking of upgrading but there’s something about it… I can use it all year without worry, it goes well, stops well and with some new suspension handles superbly. Can’t help thinking if I put 10k on a 1200 LC or towards a 1250 I’d feel I wasn’t getting the same value for money…. Time will tell

 

[Wrigsby1]

Well got round to fitting the new master cylinder today and feeling much more confident in the brakes.

I’m in a similar boat, my 3k R1100 has probably had about 2k worth of parts put in this year and I keep thinking of upgrading but there’s something about it… I can use it all year without worry, it goes well, stops well and with some new suspension handles superbly. Can’t help thinking if I put 10k on a 1200 LC or towards a 1250 I’d feel I wasn’t getting the same value for money…. Time will tell

Use it all year and park in anywhere because we're pre blingtastica... One of the reasons I like well used and a bit scruffy is the fact that it's totally for using and no-one notices you... I've tried later, newer blingier but feel comfier on what I've got and looking after it myself...

 

[MotoCammy]

Just to close out this thread for anyone who may find it in the future. Having fitted the new master cylinder and bled the brakes fully I took the GS out for a run today. After about 2 miles down the road the brakes started to stick on, slightly to begin with then fully to the extent that I ground to a halt on the side of the road. Thankfully it was a busy town area so only about 15mph. Que my frustrations and head scratching at the side of the road.

After recovering the bike back to the house I set about trying to figure out what I’d done wrong. My first port of call was the lever pivot bolt as I’ve had problems with this on an RS in the past. As soon as I removed the lever the front wheel became free.

Long story short the adjuster screw on the lever (controls the depth of the plunger onto the master cylinder) needed to be backed out a little. Obviously I should have considered this when fitting the new master cylinder rather than just a recon kit but I thought I’d share for the benefit of anyone else.

Cheers.

Cammy