WEICHAI WP6GNA User manual

Assembly & Disassembly Manual
Gas Engine
Model: WP6GNA
WEICHAI AMERICA CORP.
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Weichai America Corp.
Revision: August 2019 1
Purpose
This manual is intended to inform customers on how to assemble and disassemble theWeichai America
6 Liters naturally aspirated engine. This document will be provided to customer so they can incorporate
this information into their manuals and service documents.
Maintenance Providers
Maintenance and repair services may be performed by you or any qualified engine service provider that
you choose. However, your engine warranty does not cover damage or failure caused by improper
maintenance or repairs.
Owner’s Manual & Maintenance Records Storage & Use
Store this Owner’s Manual and Maintenance Records in a safe, visible place by your engine. The
maintenance log must be updated whenever your engine is serviced. If repairs are being done under
warranty be sure to follow proper warranty procedures.(see Weichai America CorpWarranty Procedure
Manual)
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Table of Contents
1Disassembly & Assembly of Engine.....................................................................................5
1.1 Safety Precautions............................................................................................................5
1.2 Environmental Protection Measures .................................................................................5
1.3 Notes for Disassembly and Assembly of Engine...............................................................5
2Fuel System.........................................................................................................................6
2.1 Fuel System Assembly and Disassembly .........................................................................6
2.2 LPG Intake System Assembly and Disassembly...............................................................7
2.3 NG Shut-Off Valve Assembly and Disassembly................................................................8
2.4 Electronic Pressure Regulator (EPR) Assembly and Disassembly....................................9
2.5 Mixer Assembly and Disassembly ....................................................................................9
3Intake and Exhaust System ...............................................................................................12
3.1 Intake and Exhaust System Assembly and Disassembly................................................12
3.2 Intake Manifold Assembly and Disassembly...................................................................14
3.3 Exhaust Manifold Assembly and Disassembly................................................................14
3.4 Ignition System Assembly and Disassembly...................................................................16
3.5 Signal Generator Assembly and Disassembly ................................................................17
3.6 Engine Control Unit (ECU) Assembly and Disassembly..................................................19
4Starting System .................................................................................................................19
4.1 Starting System Assembly and Disassembly..................................................................19
5Engine Accessory System .................................................................................................21
5.1 Engine Accessory System Assembly and Disassembly..................................................21
5.2 Alternator Assembly and Disassembly............................................................................21
6Closed Crankcase Ventilation (CCV) Breather System Assembly and Disassembly..........23
6.1 CCV Breather System Assembly and Disassembly ........................................................23
6.2 CCV Breather Assembly and Disassembly.....................................................................24
7Cooling System..................................................................................................................26
7.1 Cooling System Disassembly and Assembly ..................................................................26
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7.2 Fan Assembly and Disassembly.....................................................................................27
7.3 Thermostat Disassembly and Assembly.........................................................................28
7.4 Water Pump Assembly and Disassembly .......................................................................29
8Front Cover Components...................................................................................................30
8.1 Torque Vibration Damper and Crankshaft Pulley Assembly and Disassembly................30
8.2 Gear Housing Assembly and Disassembly .....................................................................31
8.3 Intermediate Gear Assembly and Disassembly...............................................................34
9Cylinder Heads and Valves................................................................................................36
9.1 Lifting Lugs Assembly and Disassembly.........................................................................36
9.2 Cylinder Head Cover Assembly and Disassembly ..........................................................36
9.3 Rocker and Rocker Shaft Assembly and Disassembly....................................................38
9.4 Tappet and Pushrod Assembly and Disassembly...........................................................39
9.5 Cylinder Heads Assembly and Disassembly...................................................................41
9.6 Assembly and disassembly of valve................................................................................44
10 Oil & Lubrication System ......................................................................................47
10.1 Assembly and disassembly of oil sump.................................................................47
10.2 Disassembly and Assembly of Engine Oil Strainer ...............................................48
10.3 Disassembly and Assembly of Lubricating System...............................................49
10.4 Assembly and disassembly of piston nozzle.........................................................49
10.5 Disassembly and Assembly of Engine Oil Pump...................................................51
10.6 Disassembly and Assembly of Engine Oil Filter....................................................51
10.7 Disassembly and Assembly of Engine Oil Cooler .................................................52
10.8 Disassembly and Assembly of Main Oil Gallery Pressure Limiting Valve..............53
10.9 Disassembly and Assembly of Deputy Oil Pressure Limiting Valve.......................54
11 Crank-rod mechanism ..........................................................................................55
11.1 Assembly and disassembly of flywheel housing....................................................55
11.2 Assembly and disassembly of flywheel and ring gear...........................................57
11.3 Assembly and disassembly of front oil seal and rear oil seal.................................59
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11.4 Assembly and disassembly of crank-rod mechanism............................................61
11.5 Assembly and disassembly of piston-rod assembly..............................................61
11.6 Assembly and disassembly of crankshaft system .................................................65
11.7 Assembly and disassembly of crankshaft bearing shell ........................................68
11.8 Assembly and disassembly of thrust plates...........................................................69
11.9 Assembly and disassembly of camshaft ...............................................................70
12 Engine block assembly.........................................................................................72
12.1 Disassembly and assembly of engine block assembly..........................................72
12.2 Steps to Assemble and disassemble Engine Block Module..................................75
13 APPENDIX A........................................................................................................78
14 APPENDIX B........................................................................................................79
15 APPENDIX C........................................................................................................80
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1Disassembly & Assembly of Engine
1.1 Safety Precautions
Please strictly comply with instructions in this manual to safely and properly disassemble and
assemble the engine.
1.2 Environmental Protection Measures
Please comply with relevant laws and regulations on environmental protection when handling oil
and hydrocarbon waste. For further instructions please contact your local officials.
1.3 Notes for Disassembly and Assembly of Engine
Failure in complying with safety regulations and basic safety practices causes the majority of
engine-related accidents. Proper training is required for all engine operators and maintenance
personnel. Any violation of instructions in this manual may result in serious injury or death.
Note: Before proceeding with any maintenance or repair operation, place a sign clearly
stating “Maintenance In Progress, Do Not Use” on the engine starter switch.
Take the following precautions before using a lockout tool and beginning maintenance or repair:
•Ensure the maintenance site and surrounding area are clean and suitable for safe operation.
•Remove any rings, necklaces, watches, or other jewelry and wear appropriate close-fit work
clothes before entering the maintenance site.
•Wear relevant protective devices (goggles, gloves, shoes, masks, work clothes, helmet, etc.)
that are in good condition prior to entering the maintenance site.
•Do not use any defective, worn, broken, or inappropriate tools.
NOTICE: THE ENGINE MUST BE COMPLETELY SHUT DOWN PRIOR TO
MAINTENANCE.
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2Fuel System
2.1 Fuel System Assembly and Disassembly
2.1.1 Fuel System Exploded View
Fig. 2-1 Exploded view of gas supply system
2.1.2 Fuel System Disassembly Procedure
1. Remove ECU.
2. Remove the LPG intake system.
3. Remove the NG intake system.
4. Remove the electronic pressure regulating system.
2.1.3 Fuel System Assembly Procedure
Reverse the Disassembly Procedure (2.1.2) to assemble the Gas Supply System.
2.1.4 Fuel System Inspection and Maintenance
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2.2 LPG Intake System Assembly and Disassembly
2.2.1 LPG Intake System Exploded View
Fig. 2-2 Exploded view of LPG supply system
2.2.2 LPG Intake System Disassembly Procedure
1. Remove the clamps from the gas hose. Separate the hose from the NG intake system.
2. Remove the nuts and washers bolting the LPG bracket to the cylinder head assembly. Separate
the LPG bracket and LPG evaporator from the cylinder head assembly.
3. Remove the water inlet and outlet fitting clamps. Disconnect the LPG evaporator from the water
inlet and outlet hoses.
4. Remove the connecting bolts and isolator cushions between the LPG evaporator and the LPG
bracket. Fully remove the LPG evaporator assembly from the LPG bracket.
5. Remove the hex nipple fitting between the LPG evaporator and LPG lock-off valve. Separate
LPG evaporator and LPG lock-off valve.
6. Remove the LPG evaporator plug and adapter from the LPG evaporator.
2.2.3 LPG Intake System Assembly Procedure
Reverse the Disassembly Procedure (2.2.2) to assemble the LPG Supply System.
2.2.4 LPG Intake System Inspection and Maintenance
1. Check the LPG gas valve and hoses for leaks.
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2. Check the coolant fittings and hoses for leaks.
2.3 NG Shut-Off Valve Assembly and Disassembly
2.3.1 NG Shut-Off Valve Exploded View
Fig. 2-3 Exploded view of electromagnetic valve
2.3.2 NG Shut-Off Valve Disassembly Procedure
1. Remove the bolts and nuts bolting the NG shut-off valve to the gas pipe joint.
2. Remove the bolts and nuts bolting the NG bracket to the NG shut-off valve. Remove the NG
shut-off valve.
3. Remove the O-ring from the groove in the NG shut-off valve.
2.3.3 NG Shut-Off Valve Assembly Procedure
Replace the O-ring and reverse the Disassembly Procedure (2.3.2) to assemble the NG
Electromagnetic Valve.
2.3.4 NG Shut-Off Valve Inspection and Maintenance
The inspection and maintenance of the NG shut-off valve must be performed at a special service
station.
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2.4 Electronic Pressure Regulator (EPR) Assembly and Disassembly
2.4.1 EPR Exploded View
Fig. 2-4 Exploded view of electronic pressure regulating valve
2.4.2 EPR Disassembly Procedure
1. Remove the socket head bolts and washers bolting the gas pipe joint to the EPR.
2. Remove the hex bolts and washers bolting the EPR to the mixer. Remove the EPR.
2.4.3 EPR Assembly Procedure
Reverse the Disassembly Procedure (2.4.2) to assemble the EPR.
2.4.4 EPR Inspection and Maintenance
The Inspection and Maintenance of the EPR must be performed at a special service station.
2.5 Mixer Assembly and Disassembly
2.5.1 Mixer Exploded View
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Fig. 2-5 Exploded view of mixer
No. Part Name No. Part Name No. Part Name
1 Screws 6 Diaphragm 11 Spring
2 Mixer Cover 7 Ring 12 Adjustment Screw
3 Spring 8 Air Fuel Regulator
Valve 13 Gasket
4 Screws 9 Diaphragm
Assembly
5 Board 10 Mixer body
2.5.2 Mixer Diaphragm Disassembly Procedure
1. Remove the screws on the mixer cover. Remove the mixer cover.
2. Remove the diaphragm spring.
3. Remove the diaphragm assembly.
2.5.3 Mixer Diaphragm Assembly Procedure
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Reverse the Disassembly Procedure (2.5.2) to assemble the Mixer Diaphragm.
2.5.4 Mixer Diaphragm Inspection and Maintenance
If gas flow is insufficient:
1. Rotate the adjustment screw clockwise to increase the flow of gas.
2. Replace the gas diaphragm with a biogas diaphragm to increase the flow of gas.
To replace the mixer diaphragm according to maintenance specifications:
1. Remove the old mixer diaphragm.
2. Check the diaphragm for deformation, tears, and deficiencies. Replace it if necessary.
3. Check the diaphragm for oil contamination and corrosion. Clean it if necessary.
4. Clean the diaphragm with a special cleaning agent.
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3Intake and Exhaust System
3.1 Intake and Exhaust System Assembly and Disassembly
3.1.1 Intake and Exhaust System Exploded View
Fig. 3-1 Exploded view of intake and exhaust system
Fig. 3-2 Exploded view of intake elbow
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3.1.2 Intake and Exhaust System Disassembly Procedure
1. Loosen the clamps on the air filter elbow, elbow pipe breather connection, and the mixer hose.
Remove the air filter elbow, elbow pipe, and mixer hose.
2. Remove the hex bolts bolting the air filter to the air filter bracket. Remove the air filter
3. Remove the socket head bolts bolting the throttle adapter to the mixer. Remove the mixer.
Note: If the EPR has not been removed, remove the hex bolts bolting the EPR to the mixer.
4. Remove the nut and bolt bolting the intake elbow to the throttle and throttle adapter. Remove
the throttle adapter and throttle together in one piece, then the throttle gasket.
Note: After removal, hold the throttle and throttle adapter together with bolt holes still
aligned to prevent the O-ring from falling out.
5. Remove the bolts bolting the intake elbow to the intake manifold. Remove the intake elbow
and intake elbow gasket.
6. Remove the nuts bolting the exhaust elbow to the exhaust manifold. Remove the exhaust pipe
and gasket. See details in Exhuast Manifold Assembly and Disassembly (3.3).
CAUTION: The exhaust elbow will be extremely hot after engine operation.
7. Remove the bolts bolting the intake manifold to the engine block. Remove the intake manifold,
cover plates, and gaskets. See details in Intake Manifold Assembly and Disassembly (3.2).
3.1.3 Intake and Exhaust System Assembly Procedure
Reverse the Disassembly Procedure (3.1.2) to assemble the Intake and Exhaust System.
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3.2 Intake Manifold Assembly and Disassembly
3.2.1 Intake Manifold Exploded View
Fig. 3-3 Exploded view of intake manifold
3.2.2 Intake Manifold Disassembly Procedure
1. Remove the nuts bolting the intake manifold to the engine block. Remove the intake manifold
and gaskets.
2. Remove the bolts bolting the cover plates to the intake manifold. Remove the cover plates and
the gaskets.
3.2.3 Intake Manifold Assembly
Reverse the Disassembly Procedure (3.2.2) to assemble the intake pipe. Recommended tightening
torque for the nuts bolting the intake pipe to the engine block is 23Nm.
3.2.4 Intake Manifold Inspection and Maintenance
1. Check the intake manifold for weld defects. Replace the pipe if necessary.
2. Check the intake pipe gaskets for damage and tears. Replace the gaskets if necessary.
3.3 Exhaust Manifold Assembly and Disassembly
3.3.1 Exhaust Manifold Exploded View
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Fig. 3-4 Exploded view of exhaust manifold
3.3.2 Exhaust Manifold Disassembly Procedure
CAUTION: All parts of the exhaust manifold and exhaust elbow will be extremely hot after
engine operation.
1. Remove the heat shield bolts and the heat shield.
2. Untie the exhaust elbow insulation ties. Remove the exhaust elbow insulation with the ties.
3. Loosen and remove the oxygen sensor.
4. Remove the nuts bolting the exhaust elbow to the exhaust manifold. Remove the exhaust elbow
and gasket.
5. Remove the nuts bolting the exhaust manifold to the engine block. Remove the exhaust
manifold.
3.3.3 Exhaust Manifold Assembly Procedure
Reverse the Disassembly Procedure (3.3.2) to assemble the exhaust pipe. Note the following
during assembly:
1. Apply molybdenum disulfide to exhaust manifold bolts before use.
2. Torque the exhaust manifold attachment bolts to the recommended tightening torque of
65~80Nm.
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3. Do not reuse exhaust manifold attachment bolts more than twice.
3.3.4 Exhaust Manifold Inspection and Maintenance
1. Check for cracks in the exhaust manifold and deformations in the exhaust elbow flange. Replace
the exhaust manifold and exhaust elbow if necessary.
2. Check the exhaust elbow flange for any air leakage. Replace the exhaust elbow gasket if
necessary.
3. Check exhaust elbow gasket for any deformation, tearing, or deficiencies. Replace it if
necessary.
3.4 Ignition System Assembly and Disassembly
3.4.1 Ignition System Exploded View
Fig. 3-5 Exploded view of ignition system
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Fig. 3-6 Exploded view of ignition system
3.4.2 Ignition System Disassembly Steps
1. Unplug the wiring harness connector from the ECU and ignition coil.
2. Remove ignition coil bolts and ignition coils.
3. Remove spark plugs.
4. Remove signal generator. See Signal Generator Assembly and Disassembly (3.5) for details.
3.4.3 Ignition System Assembly Steps
Reverse the Disassembly Procedure (3.4.2) to assemble the Ignition System
3.4.4 Ignition System Inspection and Maintenance
Inspection and Maintenance of spark plugs, ignition coils, and the signal generator must be
performed at a special service station.
3.5 Signal Generator Assembly and Disassembly
3.5.1 Signal Generator Exploded View
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Fig. 3-7 Exploded view of signal generator
3.5.2 Signal Generator Disassembly Procedure
1. Remove the connecting bolts of the pump gear and signal generator.
2. Remove the hex nuts between signal generator flange and engine block.
3. Remove the signal generator from the engine.
3.5.3 Signal Generator Assembly Procedure
1. Adjust the crankshaft to TDC: the first cylinder piston should be in its compression stroke.
Tighten the connecting bolts between the pump gear and signal generator.
2. Tighten the hex nuts between signal generator and engine block.
3. Adjust the fluted signal generator disc until its TDC mark points at the center of the speed
sensor and the predetermined ignition angle is reached.
4. Tighten the locknut on the signal generator fluted disc.
5. Tighten the hex nuts on the signal generator cover plate.
3.5.4 Inspection and Maintenance of Signal Generator
1. Check for damage to the signal generator shaft threads.
2. Check that the locknuts of the signal generator fluted disc are tightened and that the ignition
angle of the signal generator is correct.
3. Check for damage to the speed sensor, tooth disc, or housing.
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3.6 Engine Control Unit (ECU) Assembly and Disassembly
3.6.1 ECU Exploded View
Fig. 3-8 Exploded view of ECU
3.6.2 ECU Disassembly Procedure
1. Remove the fuse box bolts. Remove the fuse box from the bracket.
2. Remove the Harness ECU Connection from the ECU.
3. Remove the ECU bolts. Remove the ECU from the bracket.
3.6.3 ECU Assembly Procedure
Reverse the Disassembly Procedure (3.6.2) to assemble the ECU
3.6.4 Inspection and Maintenance of ECU
1. Check to see if any ECU connection pins are corroded, bent, broken, missing, or damaged.
Replace the pins if necessary.
2. Check the plastic portion of the ECU connection for damage. Replace the ECU if there is any
damage.
4Starting System
4.1 Starting System Assembly and Disassembly
4.1.1 Starting System Exploded View
The starter is the core component of the starting system. The starter converts battery power to
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