LEWIS AX Brake Service Kit for AX Lever and Caliper

Larger pistons call for their own seals, and the AX caliper seals come in 18mm and 20mm, so this kit is not one to swap with its AE cousin. Have your brake model confirmed first, then work through the parts by end.

Identify the AX before opening the bag

Look for the AX name on your brake rather than going by appearance. The AE kit uses smaller seals and mostly different lever codes, which makes a mix-up costly once fluid is out. If there is doubt, the kit notes recommend consulting before you buy, and a photo of the lever and caliper usually settles it.

The hose connector ring on the AX lever

One item stands out in this kit: COX030615, an O-ring for the lever oil hose connector. Changing it means disconnecting the hose at the lever, which is normally a bigger job than a seal swap, so decide early whether it is on your plan. You will also find two COX761012 O-rings for the piston sleeve.

Sorting 18mm and 20mm caliper seals

Two CMF39-HNBR seals are for 18mm and two CMF40-HNBR seals are for 20mm, and two bore cap seals come with them. Those cap seals are given by code only and are not assigned to a bore, so hold each one against the old seal. Keep the pairs separated until the pistons are back in.

• CHS35 piston body and CTZ10 sleeve
• CLS75 set screw for the piston sleeve
• CTH01 spring and CMF21 diaphragm
• CMF22 front seal and COX040715 rear seal
• COX560812 banjo fix screw O-rings, two pieces
• COX070901 caliper oil port O-ring

Bleed tools and fluid are not in the AX kit, so collect them before you begin and follow the fluid requirement of your own brake for the final fill.