Brake Reservoir Refilling

I did some work on the handle bar which requires both the brake hose to be detached from reservoir. After attaching the hose there will be trap air inside the lines and some fluid need to be top up. Here are few simple procedure to do this.


SYM specified brake fluid DOT 3 or DOT 4, I recommend DOT 4 since this one have higher boiling point that the earlier.

Make sure you have cloth covering the bike panel on the side that you want to work, slightly damp the cloth to make it absorb better.

Remove the 2 Philip screw and gently lift the cap.

Ensure reservoir is level and slowly add fluid, note you don't normally add fluid to brake reservoir unless there is leakage or work done on the bike. Fluid level drop is normal as it take up space for worn brake pad and after replacing with new pad the level will return to it initial point.

With new brake shoe, this is the level that you should have, since I had disturb the hose and some fluid loss occur I need to top up to slightly lower than this mark because my bike brake shoe is already worn.

Slowly depress the brake lever to get the air out and also change the orientation of handle to make sure all air can be displace. Few depress is necessary until you get a good pressure on the lever. This procedure is after you have disconnect the hose at the reservoir.

Once done, close the reservoir don't do it too tight since it has a rubber gasket and it should just enough to be air tight.


If you disconnect the hose at the calliper end you will need to do brake bleeding, by loosening the brake nipple at the calliper as you depress the lever and close it before the lever is release. This step need to be repeated until all air is expelled from the calliper or the bottom hose.