Fork seals

Each fork leg has an oil seal with a dust seal (wiper) above it. The oil seal keeps the fork oil inside, while the dust seal scrapes dirt off the tube before it can reach the oil seal.

A leaking seal shows up as an oily ring or film on the fork tube after a ride. The leak lowers the oil level and damping, and oil can reach the brake disc and pads – which is dangerous. Often the cause is dirt trapped under the seal: on off-road bikes, cleaning it out with a thin plastic seal tool sometimes cures the leak.

Seals are usually replaced in both legs at once, together with fresh fork oil. Check the tubes for nicks and rust, which will quickly ruin new seals. Find the right oil volume with our fork oil level calculator.