FRONT ATTACHMENT / Cylinder Disassemble Boom, Arm, Bucket Cylinders 7. Install the cylinder head (6) assembly to piston rod (1). Special tool when installing cylinder head: Boom cylinder (ST 8027) Arm cylinder (ST 8022) Bucket cylinder (ST 8021) IMPORTANT: Face the slit in cushion seal (28) to the piston. Check the direction of oil groove in cushion bearing (27). 8. Install cushion seal (28) to piston rod (1). Install cushion bearing (27) and piston (26) to piston rod (1). (Cushion seal (28) and piston (26) are not equipped for the bucket cylinder.) 9. Install shim (16) to piston rod (1). Align the matching marks before disassembling and tighten nut (15) (bucket cylinder:
piston nut (29)) by using special tool (ST 5908) and special tool for nut. Special tool when turning nut: Boom cylinder 115 mm (ST 3247) NOTE: The procedure for arm cylinder is an example. 1. Install bushing (7) into cylinder head (6). Special tool when installing bushing: Boom cylinder (ST 8027) Arm cylinder (ST 8022) Bucket cylinder (ST 8021) IMPORTANT: Check the direction to install. 2. Install U-ring (4), backup ring (3), buffer ring (5) and snap ring (8) to cylinder head (6). 3. Install wiper ring (2) to cylinder head (6) by using a plastic hammer. Special tool when installing wiper ring: Boom cylinder (ST 8027) Arm cylinder (ST 8022) Bucket cylinder (ST 8021) 4.
Install O-ring (10) and backup ring (9) to cylinder head (6). 5. Install O-ring (24) and seal ring (25) to piston (26) (bucket cylinder: piston nut (29)). After installing seal ring (25), adjust seal ring (25) by using special tool B. Special Tool A, Special Tool B: Boom cylinder (ST 2979, ST 2310) Arm cylinder (ST 2970, ST 2211) Bucket cylinder (ST 2967, ST 2090) 6. Install backup rings (23) (2 used), slide rings (22) (2 used) and (21) (2 used) to piston (26) (bucket cylinder: piston nut (29)). : 9060 N m (924 kgf m, 6680 lbf ft) Arm cylinder 130 mm (ST 3276) : 21150 N m (2157 kgf m, 15600 lbf ft) Bucket cylinder 115 mm (ST 3247) : 12200 N m (1244 kgf m, 9000 lbf ft) Special Tool:
ST 5908 W158-04-02-022 W4-2-27