Brake Fluid Replacement / Air-Bleed - Sym HD 125 Service Manual

Brake fluid replacement / Air-bleed

Connect drain hose to air-bleed valve.
Open the drain valve on the caliper and operate
the brake lever until the old brake fluid is entirely
drained out.
Close the drain valve and add specified brake fluid
into the brake master cylinder.
Recommended brake fluid: WELLRUN DOT 3
brake fluid
Connect one end of transparent hose to the drain
valve, and put the other end into a container.
Open the drain valve around 1/4 turns, and at the
same time hold the brake lever until the there is no
air bubble in the drain hose and also feeling
resistance on the brake lever.
Close the drain valve when finishing the brake
system refilling fluid procedure, and operate the
brake lever to check whether air bubble is in
brake system or not.
If brake is still soft, please bleed the system as
described below:
1. Tightly hold the brake lever and open the drain
valve around 1/4 turns, and then close the
valve.
Caution
Do not release the brake lever before the
drain valve is closed.
Always check the brake fluid level when
carrying out the air bleeding procedure to
avoid air enter into the system.
2. Slowly release the brake lever, and wait for a
few seconds until it reaches its top position.
3. Repeat the steps 1 and 2 until there is no air
bubble at the end of the hose.
4. Tightly close the drain valve.
5. Make sure the brake fluid is in the UPPER level
of the master cylinder, and refill the fluid if
necessary.
6. Cover the cap.
To this chapter contents
Air-bleed valve
Bubble
14. BRAKE
Air-bleed valve
Transparent hose
14-7