By Alan Dowds
HYDRAULIC brake setups are excellent reliable systems these days, and generally get by without too much in the way of regular maintenance. But over time, the hydraulic fluid inside the lines and calipers absorbs water from the atmosphere, and needs refreshing. Bleeding the lines with fresh fluid every six months or so can restore feel and power – and if you do any work on the brakes, like swapping lines or replacing seals, you need to bleed all the trapped air out after the work.
Here are five essential tips on bleeding your brakes.
1 Choose your kit
Strictly speaking, you don’t need anything except a spanner to open the bleed nipple, and a screwdriver to open the reservoir cap. And back in the 1980s when I started riding, that's all we had. Pump the brake lever, hold it into the bar against the pressure, loosen the nipple, let the old fluid/air out, tighten the nipple, then release the lever and repeat till (no) fade. Bosh.
Nowadays though, there are various gadgets to help speed up the process. This white bleeding jar from BikeIt has a one-way valve in the bleed hose, so you just open the nipple and pump the fluid through – the valve stops air getting sucked back into the caliper when you release the brake lever.