NUT-SPECIAL 2852277 - Caterpillar

Do not disconnect any oil lines until all pressure in the main system has been released.
1. Remove four bolts (1) securing the two oil lines to the frame. 2. Disconnect oil lines (2), (3) and (5). Disconnect six oil lines (8).3. Remove six oil lines (4) from the machine. Remove oil line (6) and (9) from the machine. Install plugs in all openings in the control valve.4. Remove three bolts (7). 5. Install tooling (A) and fasten a hoist to control valve (10). Remove the three stem control valve. The weight of the control valve is 218 kg (480 lb). The following steps are for the installation of the three stem control valve.6. Install tooling (A) and fasten a hoist to control valve (10). Put control valve (10) in position and install three bolts (7). Check the condition of the O-ring seals in all the oil lines that have been disconnected or removed. Replace if necessary.7. Connect six oil lines (8). Connect oil lines (2), (3) and (5).8. Install six oil lines (4). Install oil lines (6) and (9).9. Install four bolts (1) to secure the two oil lines to the frame.10. Fill the hydraulic tank with oil to the correct level. See the Operation And Maintenance Manual.11. Remove the air from the pilot system. See the topic, Air Removal From The Pilot Oil System, located in the 254B Excavator And Front Shove Hydraulic System, Testing And Adjusting Module, Form No. SENR3893.Disassemble & Assemble Three Stem Control Valve
Start By:a. remove three stem control valves 1. Remove two housings (1). Remove springs (3) and retainers (2) from housings (1). Remove the O-ring seal from each housing (1).2. Remove retainers (4) and spool (5) from the main valve body. 3. Remove two housings (6). Remove springs (8) and (9) and retainers (7) from housings (6). Remove the O-ring seal from each housings (6).4. Remove retainers (10) and spool (11) from the main valve body. 5. Remove two housings (12). Remove springs (14) and (15) and retainers (13) from housings (12). Remove the O-ring seal from each housing (12). On the raise boom portion of the control valve, remove additional spacer (18).6. Remove retainers (16) and spool (17) from the main valve body.
There is spring tension on housings (19).
7. Replace two bolts located diagonally on each housing (19) with two 1/21/2 -13 x 3 bolts. Remove the remaining two bolts. Slowly remove the two 1/21/2 -13 x 3 bolts to relieve the spring tension on each housing (19). Remove two housings (19). Remove the O-ring seal from each housing (19).8. Remove springs (20) and spacers (21) from housings (19). Remove spools (220 from the main valve body. The following steps are for assembly of the three stem control valve.9. Clean and inspect all parts. Carefully remove burrs by light stoning or lapping. Make sure there are no burrs or paint on mating surfaces of the valve body. Coat all parts with clean hydraulic oil. Use 1U6395 O-ring Assembly Compound to hold