K11 Owners Group

kamu

Hi folks...
I'm new to the group and have been lucky enough to find a '93 K1100RS with 25K miles. I've had quite a few different bikes in the past but this is my favorite and my first BMW. I'm having a little issue with the front brake. When I ride and use the front brake I'm getting some drops of brake fluid leaking from somewhere below the reservoir. This only seems to happen when I'm riding. If I try to get it to leak by squeezing the front brake when I stop it doesn't seem to leak. Not sure if this is ABS related or not. I'm willing to tear into it but if someone has had this issue and has some idea where I should be looking it would help. I have 2 lines going to the reservoir, one about 3/16" (5mm) diameter and that can swivel where it goes into the reservoir, the other is about 5/16" (8mm) and is bolted into the reservoir plus what I think is a wire that may go to the ABS system. Any ideas as to what I'm up against here?
Thanks for your time...
Dan

Phil Marvin · Posted: Fri Dec 18, 2009 1:41 am Post subject:

Hi, Dan,
First, where are you? I, for example, am in El Paso, TX and have had the same problem you are having and repaired my '95 K1100LT. If you were close, I would go and guide you through the procedure instead of saying to check out the "Tech Resources and Stickies" and read the thread "Phil Marvin's front master cylinder overhaul". If that doesn't fix the problem or you don't feel you want to rebuild a critical (brake system) part, then it's new master cylinder time ($$$) unless you want to replace your leaking used part with a non-leaking used part. If so, you can also contact Phil Marvin, who just happens to have a used master cylinder he bought before he attempted to (successfully) rebuild his master cylinder.
Good Luck!
_________________
Ride Safe,
Phil Marvin in El Paso, TX
'94 K75A/3
'95 K75RTP

kamu · Posted: Fri Dec 18, 2009 1:53 am Post subject:

Well, I'm in Hawaii and appreciate the fact that your'e willing to come and help. Might be a somewhat expensive option (plane tickets and all... Smile

. I'll try and find Phil's post. I kind of figured that's what I might have to do. Looks like it may be time to pull out the book and rebuild it. Can I buy a rebuild kit somewhere? Thanks for responding.

Jim · Posted: Fri Dec 18, 2009 2:20 am Post subject:

Phil Marvin · Posted: Fri Dec 18, 2009 2:30 am Post subject:

Hi, Dan,
The Tech Resources and Stickies discussion area is one below the Tech, one above the Campfire. My post is there. The "kit" is available from your dealer or from Beemer Boneyard or other parts people. It is a Magura part, whether it comes with a BMW part number or not. I did not buy mine through BMW. I bought the kit as well as the two copper gaskets which are on either side of the banjo fitting connecting the brake hose to the master cylinder. As it was, I didn't use the new gaskets; I annealed my old ones and then reused them. But I would advise having new ones on hand. That way you KNOW you won't need them!

I've been to Hawaii (1969-1972). I was on a Polaris submarine which was home ported in Pearl Harbor, but operated out of Guam. Hawaii, to me, was not a pleasant experience. I'd do most anything to not have to go there again. That said, if you enjoy it, that's great. Hopefully I can help you from afar! Good Luck!
_________________
Ride Safe,
Phil Marvin in El Paso, TX
'94 K75A/3
'95 K75RTP

kamu · Posted: Fri Dec 18, 2009 4:41 am Post subject:

Thanks folks...I do appreciate the quick response. I have a 3rd party manual and will search around a little and order a rebuild kit. It sounds like it's one of those jobs that's worse thinking about it than just jumping in and doing it. I'll post after I get it done. It's nice there's a group like this to call on when you need a little help or advice. Hope I can return the favor sometime.....Again, thanks.

BMGraeme · Posted: Fri Dec 18, 2009 5:22 am Post subject:

One think to check would be the condition of the hoses if they are the original fitments. I had a mysterious leak from "under the MC" which turned out to be a pin hole in the hose about 1 inch underneath. I decided to replace all the lines with braided hoses while I was there.
_________________
1980 CB900FA
1994 K1100RS
2008 R1200GSA

Flying Duck · Posted: Fri Dec 18, 2009 7:58 am Post subject:

BEFORE you order a rebuild kit, you want to take the master cylinder apart and inspect the wall of the cylinder bore. If it is pitted then a rebuild kit won't do you any good and you'll need to replace the master cylinder.

If you just got the bike and it's leaking then it may just be some old crud built up in there. The first thing I'd do is take the master cylinder off, remove the piston, clean the cylinder bore out with some 0000 steel wool and carefully inspect the wall of it for pitting. If it is pitted then you're going to need to replace the master cylinder. Next, clean up the piston and the seals on it and check the condition of the seals.

It may be that just disassembling it and cleaning it up will solve your problems. It's worked for me before.

Whatever you do, keep brake fluid away from painted surfaces and if you do get any brake fluid on the paint then clean it off immediately. Brake fluid likes to eat paint.

When you remove it from the bike, be very careful with the heated grip wiring. IF you break the connection where the wires meet the heating element near the end of the grip then you won't be able to reattach it.

Where are you in Hawaii?
_________________
93 LT (x2)
94 RS
86-97 K75F(K75/100/1100 Frankenbrick)
86 K75C w/paralever, hi perf cams,TURBO!
91 & 92 K75Ss
91 K1
86 custom K100
14 WR250R
IBA #17739 (SS1K, BBG, 50CC)
Buy parts HERE

kamu · Posted: Fri Dec 18, 2009 1:28 pm Post subject:

Sounds good...I'll let you know how it turns out. Flying Duck, I'm on the Big Island. Again, all the advice is appreciated. I'll follow up as soon as I get it apart.

kamu · Posted: Mon Jan 18, 2010 6:06 pm Post subject:

Well it's after the holidays, got the front master apart the bore of the cylinder looks fine so I ordered and got the new piston. The old seals seemed less firm than the new ones. I'm going to soak the piston for 15 minutes in DOT 4 and and coat the bore with DOT4 as well. From what I understand I should't push the piston to far forward as it might hurt the seal if it passes over the hole in the cylinder. I don't have a pressure bleeder so is there any way I can bleed the front brakes after I reinstall the cylinder. Tips and comments would be appreciated.

Tim (Midland Section) · Posted: Mon Jan 18, 2010 6:58 pm Post subject:

You don't need a pressure bleeder. If nothing else has been disturbed, one can just refill the reservoir, operate the lever SLOWLY (to stop fluid squirting onto the tank) the air from the pipe & the cylinder will rise through the hole. Operate a few times to feel resistance, then leave the lever tied back overnight. Release next day, should be back to normal.
HTH
_________________
Regards Tim,

Grey haired riders don't get that way by pure luck
1996 Guzzi Cali3 LAPD
1972 750 Commando
G6HRN
#485

kamu · Posted: Mon Jan 18, 2010 7:07 pm Post subject:

By tieing in overnight do you mean like you're squeezing it? Also is it ok to bleed the petcock on the front calipers? Thank you...

Scott_Anderson · Posted: Mon Jan 18, 2010 7:14 pm Post subject:

Tim (Midland Section) · Posted: Mon Jan 18, 2010 8:15 pm Post subject:

Scott is indeed correct. Once you have achieved normal operation, then you can open the caliper nipple with a length of pipe running to a jar & new fluid to top up, pump SLOWLY until the new fluid appears in the pipe. It will be a different shade. Done with care no further bleeding necessary.
_________________
Regards Tim,

Grey haired riders don't get that way by pure luck
1996 Guzzi Cali3 LAPD
1972 750 Commando
G6HRN
#485

kamu · Posted: Mon Jan 18, 2010 8:41 pm Post subject:

Thanks folks...almost got to bleeding, started filling the reservoir with fluid and the sight gage is leaking...argh!! Oh well. It was ready to fall apart and the o-ring was starting to harden. Better it happened as I was filling in my garage not on the road. Any ideas where I might find that little gem and o-ring? Guess I can take my riding jacket off for a few more days...