BUTTON 2G3787 - Caterpillar

Before removing any air system components lower the scraper bowl and apron, move the ejector forward, and block the wheels. Let the air out of air reservoirs before disconnecting lines.
1. Move ejector forward and lower the apron and bowl. Move all hydraulic levers to release the pressure in the system.2. Slowly loosen the cap for the hydraulic tank to release the pressure in the tank.3. Let the air out of the air reservoirs.4. Disconnect eight oil lines from the control valve (1). Put covers on the openings.5. Disconnect air line (2).6. Fasten a hoist to the valve as a support.7. Remove three bolts (3) and nut that hold the valve.8. Remove control valve (1). Weight is 192 lb. (87 kg).Install Hydraulic Control Valve
1. Put the control valve (1) in position using a hoist.2. Install three bolts and nut that hold the valve in place.3. Remove the covers from the openings and connect the eight oil lines to the valve.4. Connect the air line to the valve.5. Start the engine and operate the hydraulic levers to remove the air from the system.6. Stop the engine and check the oil level in the hydraulic tank.Disassemble And Assemble Hydraulic Control Valve
start by: a) remove hydraulic control valve When disassembling and assembling a hydraulic control valve group, do the work on a clean area. The valves and valve bores have precision machined surfaces. Scratches on a valve or a bent valve will not permit the valve to operate correctly. Clean all parts and put oil on them. Keep covers on all openings to prevent dirt from getting in the valve assembly. Put valve spools back in the valve body as soon as possible.1. Remove control lever housing (1) valve centering cover (2) and O-ring seal under the cover.2. Remove the bolt and lockwasher (3).3. Remove retainer (9), ring (6), springs (8), (two springs) retainer (4) and stem (5) for bowl lift cylinder.4. Inspect stem (5) and bore of body (7) for damage.5. Install stem (5), retainer (4), springs (8), ring (6), retainer (9), bolt and lockwasher (3), cover (2), control lever housing (1) and O-ring seal under the cover.6. Remove the control lever housing (10) for the ejector cylinder control valve.7. Remove the four plug assemblies (11), valve centering cover (12) and O-ring seal under the cover.8. Remove the bolt, lockwasher and detent (15).9. Remove the retainer (16), spring (13) and stem (14). Inspect stem (14) and body (7) for damage.10. Install stem (14), spring (13), retainer (16) and detent, bolt and lockwasher (15).11. Install control lever housing (10).12. Install the valve centering cover (12) and O-ring seal under the cover.13. Install the four plug assemblies (11). Tighten the plug assemblies equal amounts and move the stems to see that they operate freely in the valve body.14. Remove the control lever housing (17) for the elevator motor forward speed control valve.15. Remove the four plug assemblies (18), valve centering cover (19) and O-ring seal under the cover.16. Remove the bolt, lockwasher and