BMW Motorcycles: /5 Brake Overhaul
By Kim Dromlewicz
Disassemble and Assemble
- Remove front wheel from the BMW motorcycle.
- Remove brake drum assembly
- Check brake lining with vernier caliper (min. thickness: 1.5mm)
- Remove brake levers making sure to mark position for reinstallation
- Using eye protection, remove the two springs. NOTE: front spring
is the stronger of the two and must be installed in the same position.
- Mark brake shoes if they are to be reused.
- Remove circlips holding brake shoes onto their pivot.
- Remove brake shoes.
- Remove each brake camshaft.
- Clean and dry all parts.
- Grease the camshafts and install.
- Install brake levers.
- Grease the pivot posts and cams where they contact brake shoes.
NOTE: do not put any grease where it may contact brake shoes.
- Install the two brake springs, the stronger toward the front.
- Install the brake drum assembly on the bike.
- Install the wheel.
- Install the brake cable.
- Adjust front hand
lever to have 8 to 15mm free-play.
- Loosen locknut of adjustment cam on backing plate.
- Turn the internal hex to the left (CCW) until tight then back
until lower front brake lever has free movement of 4mm measured
at the cable anchor (end of lever) before the shoe is fully applied. a) adjusting the forward shoe first, turn adjustment cam until there is
drag on the wheel, back off until there is 4mm of movement in your
forward brake arm, visually, this should not look like it moves very much.
Both of these only partly describe what is usually needed. It
is much easier to adjust this cam stop while pulling the front brake
lever. If the brake lever isn't pulled then one is trying to apply
the brakes with that very narrow adjuster. This cam stop adjusts
the amount that the first shoe must travel before it contacts. At
that time the other shoe will start to apply and make contact. Then
the brakes will start to brake. The thing that the person should
look for when adjusting the cam stop is that the two levers will
move about the same distance when properly adjusted. The cam stop
only adjusts the trvel of one shoe. Therefore as the shoes wear
more only one can be compensated.
- Loosten the cam lock nut
- Pull the brake lever and tie it down to the bars.
- Rotate the adjuster until it comes to a stop in either direction,
then back off very slightly.
- While holding it, tighten the lock nut.
- Release the brake lever and test it for about equal travel of
the two levers. As the shoes wear out the rear lever will still
travel the same amount, but the front one's travel will be greater.