Checking The Brake Calliper Main Cylinder; Extracting The Brake Disk; Fitting The Brake Disk; Wear To The Brake Disk - Derbi GP1 50 cc Workshop Manual

Checking the brake calliper main cylinder:

- Check that the anti-dust boots are not damaged.
If they are, change them.
- Check that the piston return is not damaged. If it is, renew it.
- Check that the relief port and feed port are not blocked.
if the relief port is blocked, the brake pads will bind on the
disk. Inject compressed air to clean the ports.

Extracting the brake disk:

- Remove the front wheel.
- Unscrew the mounting bolts and extract the disk.

Fitting the brake disk

- Fit the brake disk onto the front wheel so that side (2) faces
outwards.
- Apply a temporary blocking device to the threads of the
brake disk mounting bolts(1).
- Tighten the front brake disk mounting bolts(1).
Nominal tightening torque:
0.8 ÷ 1 m.kg (8 ÷ 10 N.m)

Wear to the brake disk:

- Measure the thickness of the disks (A) at the point where
they are most worn.
- If the disk is more worn than specified in the service limit,
renew it.
Measurement area (B).
Standard thickness of the front brake disk.
3.3 ÷ 3.6 mm.
Service limit:
3.1 mm
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