Remove the air cap and depress the Schrader valve to release air from the positive air chamber. While releasing air, occasionally pull the air shaft to top out to ensure air is also released from the negative air chamber.

Clamp the dropout around the axle flats in a soft jaw vise, using a microfiber cloth to protect the finish. Double check that ALL air has been removed from BOTH the positive AND negative chambers. Failure to do so can result in injury.

Using a 13mm socket, unthread the double air assembly from the air side leg. Gently wiggle and pull to walk the double air assembly out past the dropout threads.

Using a 38mm socket, remove the air cartridge tube. A large socket driver or breaker bar may be necessary. Resistance from thread locker will be felt during removal.

With a plastic tire lever, pry the lip of the circlip retaining puck and remove it from the air shaft. Alternate prying both sides if needed until the puck can be removed.

Double check that ALL air has been removed. Pull the air shaft to ensure the negative air chamber is empty.

Use a small pick to remove the circlip from the air cartridge. Pull to remove the air shaft assembly and thoroughly clean.

Always use extreme caution when using a pick in this step or others to avoid scratching metal parts. Failure to do this can create scratches in the o-ring glands which cause leak paths for oil or air. When possible, pinch and remove o-rings rather than using a pick.

Remove and discard the main piston quad ring. Place the main piston flats into the vise jaws or secure with a 20mm wrench. Use a 13mm socket or box wrench to remove the main piston nut. Remove the main piston, then remove and discard the inner o-ring from the main piston.

Clamp the air shaft using 8mm shaft clamps. Use a 20mm socket to remove the air piston seat. Remove the air seal head assembly, top out bumper and nylon washer from the shaft assembly.

Hold the air seal head body with a thin 29mm box wrench or small Knipex. Remove the air seal head nut with a Knipex or 20mm socket/box wrench.

Remove the back up washers and quad ring, and discard the quad ring. Grease the new quad ring and reinstall with a back up ring on either side.

Apply blue Loctite (243) to the threads, thread the nut onto the seal head and torque to 6 Nm.

Reinstall the air seal head, top out bumper and nylon washer onto the shaft. Grease and install a new inner o-ring and quad ring on the main piston.

Apply red Loctite (263) to the shaft threads and thread on the air piston seat. Install the air piston. Apply red Loctite (263) to the air piston nut and install. Torque the complete shaft assembly to 6 Nm at the air piston nut.

Lightly grease the piston quad ring. Insert the shaft assembly into the air cartridge sleeve.

Install the circlip into the air cartridge and ensure it is fully seated. Align the tab of the circlip with the flat of the retaining puck and press the puck until fully seated.

Set the desired air volume setting on the double air assembly. Inspect and grease the o-rings. Do not apply thread locker. Gently insert the double air piston past the threads. Thread in and torque the double air assembly to 10 Nm using a 13mm socket.

Grease the o-ring and apply blue Loctite (243) to the threads. Thread the air cartridge assembly into the air side dropout. Torque to 36 Nm using a 38mm socket.

Clean the air leg assembly and fill to the desired air pressure.

Upon completion of the air spring service and any damper service, reinstall the air leg assembly per the 50 hour service instructions.