MTU 20 V 4000 G23 Generator Set

⚠ Engine coolant temperature max. 40 °C.

⚠ Valves must be closed.

Tools: Feeler gauge Y20010128, Torque wrench 60-320 Nm F30047446, Ring socket, 24 mm F30039526

1. Remove cylinder head cover.
2. Install barring tool.
3. Rotate crankshaft until marking OT-A1 and pointer are aligned.
4. Check TDC position of piston in cylinder A1.
5. Check valve clearance with cold engine: inlet 0.2 mm, exhaust 0.5 mm.
6. Check all clearances at firing and overlap TDC per diagram.
7. If deviation exceeds 0.1 mm, adjust.
8. Release locknut, set adjusting screw, tighten locknut to 90 +9 Nm.

Tools: Feeler gauge Y20010128, Torque wrench 60-320 Nm F30047446, Ring socket 24 mm F30039526

1. Remove cylinder head cover.
2. Install barring tool.
3. Rotate crankshaft until marking OT-A1 and pointer are aligned.
4. Check valve clearance with cold engine.
5. Inlet valves (long rocker arm) = 0.2 mm.
6. Exhaust valves (short rocker arm) = 0.5 mm.
7. Adjust if deviation exceeds 0.1 mm.
8. Release locknut, set adjusting screw, tighten locknut to 90 +9 Nm.

1. Loosen clamp.
2. Remove air filter and clamp from flange of intake housing.
3. Verify flange is clean and free of objects.
4. Place new air filter with clamp onto intake housing.
5. Tighten clamp.
6. Reset signal ring of service indicator.

1. Loosen clamp.
2. Remove air filter and clamp from flange of intake housing.
3. Verify no objects in flange of intake housing and clean it.
4. Place new air filter with clamp onto intake housing.
5. Tighten clamp.
6. Reset signal ring of service indicator.

⚠ Spring/circlip/tensioning roller preload: risk of injury; only use specified tool and equipment.

1. Remove guard cover.
2. Slacken screws (1) and (2) by half a turn.
3. Press belt tensioner fully using socket adapter on screw (3).
4. Tighten screw (2).
5. Remove used drive belt.
6. Fit new drive belt.
7. Slacken screw (2) by half a turn.
8. Tighten screw (1) to 42 Nm and screw (2) to 60-65 Nm.
9. Install guard cover.
10. Readjust belt tension after 30 minutes and after 8 hours runtime.

⚠ Spring/circlip/tensioning roller preload. Risk of injury. Only use specified tool and equipment.

Tools: Socket adapter or box wrench

1. Remove guard cover.
2. Slacken screws (1) and (2) by half a turn.
3. Place socket adapter or box wrench on screw (3) and press belt tensioner fully.
4. Tighten screw (2).
5. Remove used drive belt.
6. Fit new drive belt.
7. Slacken screw (2) by half a turn.
8. Tighten screw (1) to 42 Nm and screw (2) to 60 Nm up to 65 Nm.
9. Install guard cover.
10. Readjust belt tension after 30 minutes and again after 8 hours engine runtime.

⚠ Hot oil: wear protective clothing, gloves, goggles.

⚠ Compressed air: do not direct jet at persons; wear goggles and ear protectors.

Tools: Torque wrench 6-50 Nm F30027336

1. Remove clamp.
2. Release Tommy nut and take off cover.
3. Lift rotor, allow oil to drain, remove from housing.
4. Release rotor cover nut, take off rotor cover.
5. Remove filter sleeve and measure oil residue thickness; if >45 mm shorten interval.
6. Disassemble rotor tube, conical disk and rotor base; wash with cleaner.
7. Blow out with compressed air.
8. Check/renew sealing rings.
9. Assemble rotor tube, conical disk and rotor base with sealing ring.
10. Insert new filter sleeve with smooth paper surface facing wall.
11. Mount rotor cover with sealing ring and tighten rotor cover nut 35-45 Nm.
12. Place rotor in housing and check ease of movement.
13. Fit sealing ring, cover, Tommy nut by hand; fit clamp 8-10 Nm and cover nut 5-7 Nm.

⚠ Hot oil. Wear protective clothing, gloves, goggles. Avoid contact with skin. Do not inhale oil vapor.

⚠ Compressed air: do not direct jet at persons; wear protective goggles/safety mask and ear protectors.

Tools: Torque wrench 6-50 Nm F30027336

1. Remove clamp.
2. Release Tommy nut and take off cover.
3. Carefully lift rotor, allow oil to drain and remove from housing.
4. Release rotor cover nut.
5. Take off rotor cover.
6. Remove filter sleeve.
7. Measure thickness of oil residues on filter sleeve.
8. Assemble with new filter sleeve and sealing rings; tighten rotor cover nut 35-45 Nm, clamp 8-10 Nm, cover nut 5-7 Nm.

⚠ Coolant is hot and under pressure.

1. Provide suitable container.
2. Turn breather valve counterclockwise to first stop and remove.
3. Draw off segregated corrosion inhibitor oil in expansion tank.
4. Open drain valves/plugs and drain coolant at LT coolant pump and LT thermostat housing.
5. Drain residual coolant at intercooler.
6. Close all drain valves and install drain plugs with new sealing rings.
7. Place breather valve on filler neck and close.

⚠ Coolant is hot and under pressure.

⚠ Fill/top up coolant only into cold engine.

1. Turn breather valve counterclockwise to first stop and remove.
2. Connect pump to drain valve; open and pump coolant at 0.5 bar minimum.
3. Fill expansion tank until overflow edge reached.
4. Close drain valve and fit breather valve.
5. Start engine, run unloaded 10 seconds, stop engine.
6. Check coolant level and top up if required; repeat as necessary.

⚠ Hot oil: wear protective clothing, gloves, goggles; avoid skin contact and inhalation.

Tools: Torque wrench 6-50 Nm F30027336

1. Remove cover with O-ring.
2. Remove filter element from housing.
3. Insert new filter element in housing.
4. Fit cover with new O-ring.
5. Tighten cover screws to 10 Nm -2 Nm.
6. For diaphragm: remove cover, take off spring, seal and diaphragm.
7. Check diaphragm for damage, fit new if damaged.
8. Mount diaphragm, install new seal and spring with cover.
9. Tighten cover screws to 10 Nm -2 Nm.

Tools: Torque wrench 10-60 Nm F30510423

1. Clean very dirty covers prior to removal.
2. Remove screws.
3. Remove cover with gasket.
4. Clean mating faces.
5. Check gasket, replace if necessary.
6. Place gasket and cover on cylinder head.
7. Install screws and tighten to 42 Nm.
8. Use new gasket when installing.