CONVERSION GP-CYLINDER HEAD 2261803 - Caterpillar

(1SF, 1YK) 910 F (1SF, 1YK) 918F (2CK, 3TJ) 924F (4YN, 5NN, 6MN) 928F (2XL, 8AK) 938F (1KM, 2RM, 7SN) 928G (6XR, 7SR) 938G (4YS, 6WS) Wheel Loaders IT12B (1KF) IT12F (1KF) IT14B (3NJ) IT14F (4EL) IT18F (5EJ, 6ZF) IT24F (4NN, 6KN) IT28F (1JL, 3CL) IT28G (8CR, 9AR) IT38F (5DR, 6FN) IT38G (1CW, 7BS) Integrated Toolcarriers 446 (6XF) 446B (5BL) Backhoe Loader 515 (4LR) 525 (1DN) Wheel Skidder 12H (4XM, 2WR, 8MN, 5ZM, 4ER, 2LR, 2GS) 120H (4MK, 2AN, 6TM, 5FM, 9FN, 6NM, 9YR) 135H (3YK, 7MM) 140H (2ZK, 9ZN, 9TN, 8KM, 3AS, 8JM, 5HM) 143H (1AL) 160H (6WM, 2HS, 9JM, 2FM, 9EJ, 3GM) 163H (5AK) Motor GradersAll countershaft transmission hydraulic controls use spools made of aluminum. Aluminum spools can be identified by their brownish-green to black color and they are not magnetic.
The spools are treated electrochemically to harden the surface by a process called annodizing.
If a spool sticks, it should be replaced with a new spool. The spool should never be deburred or polished in any manner.
The act of deburring or polishing the spool removes the hard annodized surface. This exposes the softer aluminum base metal. With the anodized surface removed, the aluminum will wear at a much faster rate. Wear debris will increase spool sticking. The faster wear rate will increase the leakage in the control valve.