Brake Fluid Replacement / Air-Bleed - Sym GTS 250 Service Manual

14. Brake System

Brake fluid replacement / Air-bleed

Connect drain hose to air-bleed valve.
Open the drain valve on the calipers and delay
valve 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
Caution
Divulges the air to have to pump by the minute
first divulges, then to caliper.
May use fluid the replacement machine, the
replacement fluid, the time is quicker, the air
bubble also Compared with cannot remain
14-6
To this chapter contents
Front brake
caliper
Air-bleed valve
Bubble
Air-bleed valve
Delay valve
Air-bleed valve
Rear brake caliper
Air-bleed valve
Transparent hose