812422A 8 Mercruiser MC IV SSM

At operating temperature, the hydraulic oil tank is hot and under pressure. Hot oil can cause burns. Remove the fill cap on the hydraulic oil tank only when the engine is stopped, and the fill cap is cool enough to touch with your bare hand.
1. Release the pressure in the hydraulic system by slowly loosening the fill cap located on top of the hydraulic oil tank.2. Drain the hydraulic oil from the hydraulic oil tank. The capacity of the hydraulic oil portion of the tank is approximately 55 liters (14.5 U.S. gal).
At operating temperature, the engine cooling system is hot and under pressure. Steam can cause personal injury. Check the coolant level only after the engine has been stopped and the fill cap and radiator are cool enough to touch with the bare hand. Remove the fill cap slowly to relieve pressure. Cooling system conditioner contains alkali. Avoid contact with skin and eyes to prevent personal injury.
3. Release the pressure in the cooling system by slowly loosening the fill cap on the radiator.4. Drain the coolant from the cooling system into a suitable container. The capacity of the cooling system is approximately 25.7 liters (6.68 U.S. gal). 5. Remove the two nuts and bolts that fasten clamp (2) to brace assembly (1).6. Mark or identify the cable assemblies for installation purposes. Disconnect cable assemblies (3) and (4) from the quick start post. 7. Mark or identify the cable assemblies for installation purposes. Disconnect cable assemblies (7) from the disconnect switch.8. Remove the disconnect key from the disconnect switch. Remove nut (6), and remove disconnect switch (5) from the brace assembly. 9. Remove nut and bolt (8) that fastens the fuel line to brace assembly (1).10. Remove four bolts (9) and four nuts and bolts (10). Use two persons to remove brace assembly (1) from the machine. The weight of the brace assembly is 27 kg (60 lb). 11. Disconnect hose assemblies (11) and (12). Cap and plug immediately.
View From Under Machine12. Disconnect hose assemblies (13). Cap and plug immediately. 13. Disconnect hose assemblies (14) and (15). Cap and plug immediately.14. Remove the nut and bolt that fastens hose assembly (15) to the clip and other hose assembly. 15. Disconnect hose assemblies (16) and (17). Cap and plug immediately. 16. Disconnect hose assemblies (18) and (19). Cap and plug immediately. 17. Disconnect hose assembly (20). Cap and plug immediately. To gain access to hose assembly (21), it is necessary to disconnect hose assembly (22) (not shown).18. Disconnect hose assembly (22) (not shown). Disconnect hose assembly (21). Cap and plug immediately.
View From Under Machine19. Disconnect hose assembly (23). Cap and plug immediately. 20. Disconnect hose assemblies (24) and (25). Cap and plug immediately. 21. Disconnect hose assemblies (27) and (28). Cap and plug immediately22. Remove bolt (26) that holds the clip, and move hose assembly (27) out of the way. 23. Close fuel shut-off valves (29). Disconnect fuel lines (30) and (31) from the shut-off valves. Cap and plug immediately.24. Remove bolt (32) and the clamp holding fuel lines (30) and (31) to the side of the engine compartment.25. Remove bolt (33) (not shown) and the clamp holding fuel line (30) to the side of the engine compartment. 26. Disconnect hose assembly (34). Cap and plug immediately.27. Remove bolt (35) and the hose clamp, and move the two hose assemblies out of the way. Remove the two bolts and hose clamp (36), and move the three hose assemblies out of the way. 28. Disconnect hose assemblies (37). Cap and plug immediately. 29. Remove the bolts that fasten two clamps (38) and cable assembly (4) to the frame. Move the cable out of the way. 30. Disconnect hose assembly (40) from the steering pump, and remove the hose assembly from the engine. Cap and plug immediately.31. Disconnect hose assembly (39) from the steering pump. Cap and plug immediately. 32. Put identification marks on two wires (41) for installation purposes. Disconnect the wires from the fuel level sending switch. Remove the cable ties that fasten wiring harness (42) to the fuel/hydraulic oil tank and the frame. Move the wiring harness out of the way. 33. Put identification marks on two wires (43) for installation purposes. Disconnect the two wires from the hydraulic oil temperature switch.34. Remove the two bolts that fasten starter relay switch (44) to the frame. Remove all the cable ties that fasten the harness assembly to the frame. Move the wiring harness out of the way. 35. Remove the bolt and three screws (45), and separate electrical connector (46). Disconnect electrical connector (47).36. Remove the nut that fastens ground wire (48) (not shown) to the frame. Disconnect the three electrical connectors (not shown) which are located under electrical connector (46). Remove all the cable ties that hold the wiring harnesses to the frame.
View From Under Machine37. Disconnect cable assembly (ground) (49) from the engine. 38. Remove four nuts and bolts (50) that hold the engine to the frame of the machine. 39. Attach Tooling (A) and a hoist to engine (51) as shown. Make sure all the necessary hose assemblies and electrical wires have been disconnected. Carefully remove the engine, radiator and pumps as a unit from the machine. The weight of the engine, radiator and pump as a unit is 726 kg (1600 lb). After the engine has been installed, fill the cooling system with coolant to the correct level. Fill the hydraulic oil tank to the correct level. See the Operation & Maintenance Manual for the correct filling procedures. For installation of the engine, reverse the removal steps.