K11 Owners Group

buckles · Posted: Thu Jan 12, 2012 7:12 am Post subject: Rear brake pedal adjustment

I have just fitted a new rear master cylinder and I am not sure if I have done the adjustment correctly. Firstly I am not sure how far the pushrod should be threaded into the actual pedal and then the locknut tightened.
I also am having difficulty understanding the .2mm gap which is supposed to exist between the brake pedal adjustment bolt and the frame.
What I am referring to is described on page 34.30 of the workshop manual.
Clymer does not refer to this .2mm gap at all.
Ian

_________________
Ian, owner of:-
1999 K1100 LT

SugarHillCTD · Posted: Thu Jan 12, 2012 7:44 am Post subject:

Have you downloaded the free manual from here?

http://www.carlsalter.com/motorcycle-manuals.asp

Just another source.
_________________
John & Cathy

'92 K100RS4V Pearl White SOLD
'04 K1200GT
IBA Several-SS1k, BBG, 50CC NYC to S.F.

buckles · Posted: Thu Jan 12, 2012 8:43 am Post subject:

Yes John, I printed the manual when I found the free download. I have made a neat folder with tabs for all the chapters. cheers
_________________
Ian, owner of:-
1999 K1100 LT

Stoked Steve · Posted: Thu Jan 12, 2012 8:33 pm Post subject:

I believe it is refering to how much free play, "gap" there should be between the top of the adjusting screw head and the part that it connects with when you depress the lever.

If I recall, several folks have not set this gap and had the rear brake drag and catch fire (or seriously over heat)!

My manual page has numbers and arrows that point it on those same photos, but I can't figure out how to copy and paste a PDF page...

Be careful with it!
_________________
Steve
Virginia Beach, VA
93 K1100RS Mystic Red SOLD
12 Suzuki DL650A VStrom

buckles · Posted: Thu Jan 12, 2012 11:12 pm Post subject:

Steve, thanks I have already had the rear brake dragging a little after only travelling a short distance so I went home, made more adjustments and it is ok now. I 'released' the brake by screwing the pushrod further into the brake pedal thereby taking all pressure off the master cylinder. I think I now have this pushrod in a more natural psition in that it is not holding any pressure on the master cylinder piston in the released position.

I have adjusted the pedal using the adjusting screw head which sandwiches a shim which I think operates the brake light but I cannot see how I can introduce the .2mm clearance. Also the locknut seems impossible to tighten with a spanner.
_________________
Ian, owner of:-
1999 K1100 LT

rbm · Posted: Fri Jan 13, 2012 8:31 am Post subject:

In the rear master cylinder brake assembly, there are two adjustments - (1) gap between the master cylinder plunger and the brake pedal and (2) the gap between the brake pedal and the brake switch. The manual page 30.34 describes those adjustments. The 0.2mm gap should exist between the brake switch arm and the frame (the brake switch arm rests on the brake pedal). When the brake is applied, the switch arm releases the microswitch just at the brake contacts the plunger, turning on the brake light. This gap ensures that the switch actuates at the correct time when the brake is applied. The second gap is not specified in the text but should exist between the brake pedal and the actuating plunger of the master cylinder while the brake pedal is at rest. This free play is narrow enough that it ensures the plunger is not engaged but not too wide as to cause excessive brake pedal travel before engaging the master cylinder. It's up to you but maybe starting with adjusting screw 3 until it contacts the master cylinder plunger then backing off 1/3 to 1/2 turn.
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- Robert
1987 K75 @k75retro.blogspot.ca
2011 Moto Guzzi V7 Racer

rkildu · Posted: Mon Jan 16, 2012 3:50 pm Post subject:

This thread had me concerned since I had replaced my master cylinder a while back and was having problems with the brake light staying on. So I studied the diagram and instructions in the manual and headed to the garage to check things out.

After going through the process and checking the results I have concluded the intent is to make sure that the brake light comes on at the proper time and to make sure that the brakes are not rubbing when the pedal is not depressed.

The process assures that you have a minimum of 0.2mm travel, measured at the pedal stop, to provide that clearance.

After some consideration I decided that this is too close. I wanted more pedal travel than that, so I backed out the master cylinder adjuster to give me about 2.5 mm at the pedal stop. This allows me to tap the pedal and flash the brake light without engaging the brake but still gives me a pretty fast brake engagement.

The important thing is to make sure that the brake isn't dragging when the pedal is released.

Anyway, that's my take on it.
_________________
Rod Kilduff
97 K1100LT HighLine
82 R100Lufty

Stoked Steve · Posted: Mon Jan 16, 2012 8:33 pm Post subject:

drikko · Posted: Mon Jan 16, 2012 9:03 pm Post subject:

It would slow you down!!
_________________
K1100RS '97
Laverda RGS 1000 '84
Jim Young Trailer Sailer 5.7M WB

DISCLAIMER:- Anything I say may have been when I was drunk so please don't take it personally.

'Bigamy is having one wife/husband too many. Monogamy is the same.'
Oscar Wilde

Al. · Posted: Wed Aug 14, 2013 5:09 pm Post subject:

I was doing same but just cannot get the 2mm gap at all. Seems impossible. I understand the play at the master cylinder requirement ok
but no way can I get the 2mm.

Just figured it - advice from a guy on this site matched my brain.

http://www.motobrick.com/index.php