0986281 JOHNSON RELAY & CIRCUIT BREAKER ASSY

At operating temperature, the hydraulic oil is hot and under pressure. Hot oil can cause burns. To prevent possible personal injury, release the pressure in the implement hydraulic circuits (boom, stick and bucket) before any hydraulic lines or components are disconnected or removed.
1. Release the pressure in the hydraulic system as follows: a. Lower the blade to the ground if so equipped.b. Fully retract the rod in the stick cylinder.c. Adjust the position of the bucket so it will be flat on the ground when the boom is lowered.d. Lower the boom until the bucket is flat on the ground.e. Shutt off the engine, and put the hydraulic activation control lever in the "Lock" position.f. Move the control levers for the boom, bucket, stick and swing through their full travel strokes. This will relieve any pressure that may be present in the pilot system.g. Slowly loosen the Fill/Vent plug on the hydraulic oil tank to release the pressure.h. Tighten the Fill/vent plug on the hydraulic oil tank.i. The pressure in the hydraulic system has now been released. Lines and components can now be removed.2. Remove the plug from the bottom of the hydraulic oil tank. Install the ecology drain valve to drain the oil from the hydraulic oil tank. Drain the oil into a suitable container for storage or disposal. The capacity of the hydraulic oil tank is 57 liters (14.8 U.S. gal). 3. Open right rear access door (1) to the engine/main hydraulic pump compartment. 4. Remove the bolts and washers that hold sheet assembly (2) in position above the main hydraulic pump. Remove the sheet assembly. 5. Remove all bolts (3) and the washers that hold sheet assemblies (4) and (5) in position. Remove the sheet assemblies from between the engine and main hydraulic pump.6. Put identification marks on all hose assemblies (6) and tube assemblies that are connected to the main hydraulic pump. Disconnect the hose assemblies and tube assemblies. Put plugs in the lines to prevent oil loss and to keep dirt out of the hydraulic system.
Do not attempt to remove the main hydraulic pump by removing four bolts (7) that hold the pump to the cover and flywheel housing. The bolts are required to be tightened from the coupling side of the cover. Therefore, the main hydraulic pump can only be removed by removing the bolts that hold the cover to the flywheel housing.
Typical Example7. Fasten a lifting sling and a hoist to the main hydraulic pump (8) as shown. Put slight lifting tension on the main hydraulic pump. Remove 12 bolts (9) and the washers that hold the main hydraulic pump and cover to the flywheel housing.
The main hydraulic pump must be held level during removal to prevent binding of the coupling in the flywheel.
8. While keeping the main hydraulic pump level, remove it and the drive coupling from the flywheel and flywheel housing. The combined weight of the main hydraulic pump and the pump drive coupling is approximately 64 kg (140 lb). 9. Remove six bolts (10), the washers and coupling (11) from the flywheel. 10. Loosen two setscrews (12). Remove coupling assembly (13) from shaft (14) of the main hydraulic pump. 11. Disassemble coupling assembly (13). Remove six socket head bolts (16) and six couplings (17) from hub (15).
Typical Example12. Remove the four nuts, washers and bolts (7) that hold cover (18) to the main hydraulic pump. The following steps are for the installation of the main hydraulic pump and pump drive coupling. Four bolts (7) that hold cover (18) to the main hydraulic pump are installed from the back side of the cover.13. Put cover (18) in its original position on the main hydraulic pump. Install four bolts (7), the washers and nuts that hold it. 14. Assemble coupling assembly (13). Put six couplings (17) in position on hub (15). Install six socket head bolts (16) that hold the couplings in position. 15. Apply a thin coat of 5P-0960 Multipurpose Grease on the splines of shaft (14). Slide coupling assembly (13) on the shaft. Position the face of the coupling assembly so it is flush with the end of the shaft. Tighten two setscrews (12) to a torque of 70 8 N m (50 6 lb ft). 16. Be sure the mating surface of coupling (11) and the flywheel are clean. Put coupling (11) in position in the flywheel. Install six bolts (10) and the washers that hold it. 17. Fasten a lifting sling and a hoist to main hydraulic pump (8) as shown. While holding the main hydraulic pump level, put it in position on the engine flywheel. Be sure the coupling assemblies are in alignment with each other. Push the main hydraulic pump against the flywheel housing. Install 12 bolts (9) and the washers that hold the main hydraulic pump to the engine flywheel housing. 18. Check the condition of the O-ring seals used in the end of hose assemblies (6) and the tube assemblies that connect to the main hydraulic pump. If any of the seals are damaged, use new parts for replacement.19. Connect hose assemblies (6) and the tube assemblies to the main hydraulic pump in their original locations.20. Put sheet assemblies (4) and (5) in position between the engine and main hydraulic pump. Install bolts (3) and the washers that hold the sheet assemblies in position. 21. Put sheet assembly (2) in position above the main hydraulic pump. Install the bolts and washers that hold it.22. Fill the hydraulic oil tank with oil to the correct level. See the Operation & Maintenance Manual for the correct filling procedure.
The main hydraulic pump must be filled with clean hydraulic oil before operation or damage to the components will result. Also, the air must be purged from the main hydraulic pump to prevent component damage.
23. Purge the air from the main hydraulic pump. See the topic "Purge Air From Main Hydraulic Pump" in the 307 Excavator Machine Systems Disassembly & Assembly module, SENR6199.