# Seal Replacement S2/K2 Type

Atlas Copco use different seal configurations due to differences in tensioner specifications and tensioner usage environments. This section details the replacement of S2/K2 type high pressure seals.

1. Make note of the correct orientation of the triangular backup ring.

2. Put the outer backup ring into the piston outer seal housing.

3. Position and stretch the outer seal into the piston outer seal housing.

   The seal fits above the backup ring.

4. With a rounded smooth screwdriver, push the seal until the seal clips into the seal housing.

   Make sure that the seal and backup ring are fully seated around circumference.

5. Squeeze the inner seal into the inner seal housing.

6. Push the inner seal in place with a smooth rounded screwdriver.

7. Put the inner backup ring below the inner seal.

8. Carefully bend the backup ring to enable it to clip into position. Make sure that the seal and backup ring are fully seated around the circumference.