Doosan P126TI-II Engine

1. Loosen fixing bolts (M8) of injection pump driving gear.
2. Turn crank pulley clockwise until V-groove of flywheel housing sight hole aligns with injection timing degree.
3. Turn flange until injection pump pointer mark matches mark (FB) on drive gear flange.
4. Tighten bolt M8 to specified torque being careful not to move drive gear.
5. Recheck the injection timing start point of fuel delivery.

⚠ Only adjust the valve clearance when the engine is cold.

Tools: Feeler gauge, Ring spanner

1. Rotate crankshaft so #1 cylinder is at compression TDC.
2. Loosen lock nut of #1 cylinder rocker arm.
3. Push feeler gauge between rocker arm and valve stem.
4. Adjust clearance screw and tighten lock nut.
5. Rotate crankshaft; when a cylinder reaches compression TDC adjust its valve clearance.
6. When a cylinder is at valve overlap, adjust the cylinder at compression TDC.

Tools: Compression pressure gauge, Gauge adapter

1. Warm up the engine then stop it and remove nozzle assemblies.
2. Install special tool (gauge adapter) in nozzle holder hole.
3. Connect the compression pressure gauge to the adapter.
4. Cut off fuel circulation, rotate the starter, measure each cylinder pressure.

⚠ Fuel is highly inflammable; no naked flames or sparks.

1. Loosen the air bleeding plug on the fuel filter.
2. Operate the priming pump by hand to bleed air.
3. Operate the priming pump until air is discharged completely.
4. Close the plug screws of the filter and the pump.

⚠ Do not mix antifreezes from different manufacturers.

⚠ Discard exchanged coolant according to regulations.

1. Ensure that the engine is cool.
2. Open the radiator cap.
3. Pour the coolant in slowly.
4. Be sure that the air is gone from the cooling system.
5. Check the coolant level when warmed up and replenish if necessary.

⚠ Always wear protective goggles.

⚠ Never use steam spray, gasoline, alkali or hot cleansing solution.

Tools: Air gun, Protective goggles

1. By compressed air: use air gun at 90° from inside, blow from inside out.
2. Do not exceed 5 bars.
3. By washing: preclean with compressed air, soak in warm solvent 10 minutes, agitate 5 minutes.
4. Rinse with clean water, dry at room temperature fully before reassembling.

⚠ When removing the pressure filler cap while hot, cover with a rag and turn slowly.

⚠ Never open the radiator cap while the engine is overheated.

1. Remove the pressure cap.
2. Open the drain valve located at the bottom of the radiator to drain coolant.
3. Loosen the coolant drain plug of the cylinder block.
4. Drain cooling water in the oil cooler.

⚠ Do not add so much engine oil that the level rises above max. marking.

1. While oil is still hot, take out the dipstick.
2. Remove the drain valve from oil pan and drain plug from oil filter head, drain engine oil.
3. Reassemble drain valve with oil pan and drain plug with oil filter head.
4. Refill with new engine oil at the oil filler neck in accordance with engine oil capacity.
5. Operate engine at idle for a few minutes to circulate oil.
6. Shut down engine, wait 10 minutes, measure quantity and refill if necessary.

⚠ Tighten the drain plug after draining engine oil.

⚠ Use DOOSAN genuine oil filter cartridge.

Tools: Filter wrench

1. Drain engine oil by loosening the drain plug on the filter head.
2. Loosen the oil filter by turning counter-clockwise with a filter wrench.
3. Wipe clean the fitting face of the filter body.
4. Lightly oil the O-ring and turn the filter until sealing face fits.
5. Turn 1-1/4 turns further with the filter wrench.

⚠ During warranty, dismantling must be done in an approved workshop.

⚠ Change antifriction bearings, O-ring seal, preloading washer and adhesive paste.

Tools: Ratchet spanner + extension, Torque wrench, Flat spanners 8/10/18 mm, Socket set 8-30 mm, Puller

1. Remove box lid, NDE panel and the 2 screws from part (122).
2. Disconnect stator outputs T1 to T12 and auxiliary winding wires AREP (X1,X2,Z1,Z2).
3. Disconnect exciter wires (5+,6-).
4. Remove air inlet louvre (51), bearing thrust screws (72) and all 4 screws (37).
5. Remove shield (36), take out bearing (70) with a puller.
6. Fit new bearing after heating by induction to approximately 80°C.
7. Mount new preloading washer (79) + new O-ring seal (349) and coat bearing seat with adhesive paste.