Serpent SER500904 Shock Cap O-Ring 13mm Replacement Seal for RC Shocks  [SER500904]

Overview of the 13mm cap seal

The Serpent SER500904 Shock 13mm cap o-ring is a dedicated sealing ring fitted at the shock cap interface. It retains oil inside the shock body and stops dirt entering where the cap joins the body, which supports steady damping characteristics.

Replace the o-ring when the original shows flattening, cracks, or oil leakage. This seal is located at the cap rather than on pistons or shafts, so swapping it out only requires removing the cap. Clean the seating groove and inspect the cap surface for damage before refitting to ensure a reliable seal.

For tuning consistency, a correctly installed 13mm cap o-ring keeps oil levels stable between runs. Change the cap seal as part of scheduled shock maintenance to avoid intermittent leaks that can affect handling and setup precision.