Brake bleeding

[ajd]

I've searched for threads about brake bleeding but perhaps there's room for one other...

I have a 1996 1100GS with ABS and there's a slight weep of hydraulic fluid from the front master cylinder. The reservoir level never seems to go down but there's often a slight drip inside the hand guard and the underside of the cylinder is moist. If I pump the brake lever I can see tiny 'bubbles' in the moisture around the cylinder so I deduce there is a leak. I had the piston seals changed a few years ago by someone else but I'm not sure how good a job they did...obviously not very well! So I'm going to do it myself this time.

I'm scared to death of bleeding the system, never done it before and all those nipples on the pressure modulator are a worry (I know I shouldn't need to bleed from there though...)

I've seen threads talking about speed bleeders, I've even seen the You Tube video. Very impressive. But is a pressure bleeder worthwhile? Anyone got any experience of those?

Given the age of the bike, might it be worth just cutting my losses and putting on a refurbished cylinder from Motorworks? Thanks.

 

[Disaster Area]

My bike is the same age and had the same problem.
I bought a repair kit and did it myself and there is still an occasional drip, but I can't tell if your drip is more than mine! If I remember correctly, you don't need to bleed the system after doing the seal.

I recently put braided lines on the bike and bled the system myself. I did use a speed bleeder, mainly because it meant I could buy another tool!
There is a really good video on YouTube from the Illinois BMW riders group.

If I can do it, anyone can!

 

[beemer pimp]

Corrosion build up in cylinder that what cause leak , as well side glass leaks sometimes so check that.
What concerns bleeding, take pipe off cylinder and keep at highest point when do job, then when reassemble back fill cylinder with fluid then push break pistons in all the way with cylinder cap open and with bit luck you drive air out

 

[beemer pimp]

And me personally no need replacing seals

 

[kennyc]

I had this problem on my R1100RT it first became obvious after flushing the system (apparently during flushing you are prone to move the lever more than normal allowing the seals to rub on corroded cylinder walls) I rebuilt it and cleaned the cylinder, this lasted well for 2-3 years and then last year I came out of a friends house in Luxembourg (where the temp was 38C in the shade, and the bike wasn't in the shade!) to find it weeping all over the tank it was OK for the rest of the trip and I kept it from doing more damage by wiping it and making sure I left it in the shade.
my point being that eventually the bores wear and even new seals are not going to do the job, I bought a new Magura master cylinder from Beemerboneyard although Motorworks also do them.

 

[ajd]

Thanks for the responses chaps. The story has moved on, the job is definitely now to replace the entire master cyclinder. See my thread 'Front brake master cylinder can't get brake lever off' for a horror story.

 

[beemer pimp]

Drill it out , don't give up man