1. Remove the 2 underdrive brake piston seals from the underdrive brake piston.
2. Clean all the underdrive brake components and dry thoroughly.
3. Inspect the underdrive brake discs for excessive wear or damage and replace as necessary.
4. Inspect the underdrive brake piston for cracks or porosity and replace as necessary.
5. Inspect the underdrive brake piston return spring for distortion or weakness and replace as necessary.

Install the new underdrive brake piston seals onto the underdrive piston.