JCB 672 Mechanical Engine Service Repair Manual Instant Download

Foreword The Operator's Manual You and others can be killed or seriously injured if you operate or maintain the machine without first studying the Operator's Manual. You must understand and follow the instructions in the Operator's Manual. If you do not understand anything, ask your employer or JCB dealer to explain it. SERVICE MANUAL Do not operate the machine without an Operator's Manual, or if there is anything on the machine you do not understand. Treat the Operator's Manual as part of the machine. Keep it clean and in good condition. Replace the Operator's Manual immediately if it is lost, damaged or becomes unreadable. JCB 672 Mechanical Engine Contents 01 - Machine 06 - Body and Framework 09 - Operator Station EN - 9806/6900 - ISSUE 3 - 2016-08-22 15 - Engine 18 - Fuel and Exhaust System 21 - Cooling System 33 - Electrical System 72 - Fasteners and Fixings 75 - Consumable Products 78 - After Sales This manual contains original instructions, verified by the manufacturer (or their authorized representative). Copyright 6-08-22 JCB SERVICE All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any other means, electronic, mechanical, photocopying or otherwise, without prior permission from JCB SERVICE. www.jcb.com

15 - Engine 00 - General 00 - General 00 - General Introduction Introduction ...................................................... 15-3 Health and Safety ........................................... 15-7 Technical Data ................................................. 15-8 Component Identification ................................. 15-9 Operation ....................................................... 15-14 Fault-Finding .................................................. 15-17 Drain and Fill ................................................. 15-26 Clean ............................................................. 15-26 Check (Pressure) .......................................... 15-28 Remove and Install ....................................... 15-30 Store and Recommission .............................. 15-34 Basic Description The 6 cylinder mechanical engine has fuel ignited by compression ignition (C.I.). The engine operates on a four stroke cycle. The engine is started by an electric starter motor. The starter motor turns the engine via a pinion and teeth on the engine flywheel, refer to (PIL 09-75). When the engine runs the crankshaft drives the camshaft via gears. The camshaft opens and closes the inlet and exhaust valves and via push rods in time with the four stroke cycle. The engine has 24 valves, 2 inlet and 2 exhaust valves for each cylinder. The crankshaft also drives a mechanical fuel injection pump via gears. The pump injects fuel via injectors, or atomisers into each cylinder in time with the four stroke cycle. The pump injects fuel via injectors, or atomisers into each cylinder in time with the four stroke cycle. The pump is part of the mechanically actuated fuel injection system, refer to (PIL 18-00). Air is drawn into the engine, via the inlet manifold and exhaust gases exit via the exhaust manifold. The engine uses a turbocharger which pressurises the air at the inlet manifold, refer to (PIL 18-36). A mechanical lubrication oil pump is driven by the crankshaft via gears. The pump pressurises and circulates oil for engine lubrication and cooling purposes. A drive belt driven by the crankshaft, drives a coolant circulation pump, alternator, radiator cooling fan and other ancillaries such as an air conditioning compressor. 15 - 3 9806/6900-3 15 - 3

15 - Engine 00 - General 00 - General Figure 3. 1 Flywheel 3 Camshaft 5 Exhaust valves (12 off) 7 Turbocharger 2 Crankshaft 4 Inlet valves (12 off) 6 Push rods (12 off) 8 Lubrication oil pump 15 - 4 9806/6900-3 15 - 4

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15 - Engine 00 - General 00 - General Internal As viewed on the right hand side. Refer to Figure 4. The following identifies the main internal components of a typical engine assembly. Some variants may differ in detail. Figure 4. 1 3 5 7 9 Rocker assembly Valve bridge piece (12 off) Exhaust valve (12 off) Connecting rod assembly (6 off) Main bearing - crankshaft (7 off) 2 4 6 8 10 Valve bridge piece (12 off) Inlet valve (12 off) Piston assembly (6 off) Crankshaft Big end bearing - crankshaft/connecting rod (6 off) Flywheel 11 Front crankshaft oil seal (not shown) 12 15 - 5 9806/6900-3 15 - 5

15 - Engine 00 - General 00 - General 6a 6c 6d Piston ring - top compression (6 off) Piston ring - oil control (6 off) Gudgeon pin circlip (12 off) 6b 6d Piston ring - 2nd compression (6 off) Gudgeon pin (6 off) As viewed on the rear left side. Refer to Figure 5. Figure 5. 1 Flywheel 2 Fuel injector (atomiser) (6 off) 4 Lubrication oil pump 6 Tappet (12 off) 8 Flywheel hub 1a 3 5 7 Flywheel - crankshaft fixing bolts (8 off) Camshaft drive gear Camshaft Push rod (12 off) 15 - 6 9806/6900-3 15 - 6

15 - Engine 00 - General 00 - General Health and Safety accordance with local regulations. Use authorised waste disposal sites. Hot Components Touching hot surfaces can burn skin. The engine and machine components will be hot after the unit has been running. Allow the engine and components to cool before servicing the unit. Turning the Engine Do not try to turn the engine by pulling the fan or fan belt. This could cause injury or premature component failure. Notice: The engine and other components could be damaged by high pressure washing systems. Special precautions must be taken if the machine is to be washed using a high pressure system.Make sure that the alternator, starter motor and any other electrical components are shielded and not directly cleaned by the high pressure cleaning system. Do not aim the water jet directly at bearings, oil seals or the engine air induction system. WARNING! To bleed the injectors you must turn the engine. When the engine is turning, there are parts rotating in the engine compartment.Before starting this job make sure that you have no loose clothing (cuffs, ties etc) which could get caught in rotating parts.When the engine is turning, keep clear of rotating parts. Notice: Clean the engine before you start engine maintenance. Obey the correct procedures. Contamination of the fuel system will cause damage and possible failure of the engine. Notice: Do not exceed the correct level of engine oil in the sump. If there is too much engine oil, the excess must be drained to the correct level. An excess of engine oil could cause the engine speed to increase rapidly without control. WARNING! The engine has exposed rotating parts. Switch off the engine before working in the engine compartment. Do not use the machine with the engine cover open. WARNING! Hot oil and engine components can burn you. Make sure the engine is cool before doing this job.Used engine crankcase lubricants contain harmful contaminants. In laboratory tests it was shown that used engine oils can cause skin cancer. Notice: A drive belt that is loose can cause damage to itself and/or other engine parts. WARNING! Do not open the high pressure fuel system with the engine running. Engine operation causes high fuel pressure. High pressure fuel spray can cause serious injury or death. CAUTION! It is illegal to pollute drains, sewers or the ground. Clean up all spilt fluids and/or lubricants.Used fluids and/or lubricants, filters and contaminated materials must be disposed of in 15 - 7 9806/6900-3 15 - 7

15 - Engine 00 - General 00 - General Technical Data Table 5. Basic Engine Data (Dieselmax 672 Mechanical Engine) Engine EC - 6 Cylinder Mechanical, Turbocharged with Intercooler Non-emission 1800 rpm 680 kg (1500 lb) 6 106 mm (4.173 in) 135 mm (5.314 in) In line 4-stroke 1-5-3-6-2-4 7.148 litres 18:1 see note Clockwise Emission compliance Rated speed Weight (Dry): Number of cylinders Nominal bore size Stroke Cylinder arrangement Combustion Cycle Firing order Displacement Compression ratio Engine Compression Direction of rotation (viewed from front {crankshaft pulley} end) Valves Valve clearances measured at the tappet end of the rockers (measured cold): - Inlet - Exhaust Lubricating oil pressure Combustion system High pressure fuel pump (1) Dry weight. No cooling fan drive. (2) Compression variance between each cylinder should be no greater than 3.5 bar (50 lb in2). (3) Dependent on engine temperature and speed. (1) (2) 4 per cylinder see note (2) 0.28 0.34mm 0.43 0.5mm 1.6 - 6.5 bar (23 - 91lb in2) Direct injection, mechanical fuel injection Mechanical inline (3) 15 - 8 9806/6900-3 15 - 8

15 - Engine 00 - General 00 - General Component Identification 6 Cylinder Mechanical Engine The following identifies the main components of a typical engine assembly visible from the exterior. Some variants may differ in detail. Figure 6. Left hand Side L A K B C D J E H G F A Lubrication oil dipstick C Lubrication oil filler cap E Torsional vibration damper G Bedplate housing B Fuel injectors and high pressure fuel pipes D Rocker cover F Lubrication oil sump H Oil cooler housing with ports for remote oil filter 15 - 9 9806/6900-3 15 - 9

15 - Engine 00 - General 00 - General J Fuel injection pump L Lifting eye head K High pressure fuel pipes Figure 7. Right hand side E N F A K B G H J C L M D p A Timing gear case C Bedplate housing E Turbocharger G Alternator J Coolant inlet/radiator hose connector B Flywheel housing D Lubrication oil sump F Exhaust manifold H Coolant pump housing (crankcase) K Heavy duty PTO (Power Take-Off) (blanking cover if no device is installed) M Turbocharger oil drain line P Oil drain plug (sump) L Starter motor assembly N Turbocharger oil feed line 15 - 10 9806/6900-3 15 - 10

15 - Engine 00 - General 00 - General Figure 8. Crankshaft pulley (front) end A L K C B G J H D F E A Rocker cover C Crankcase E Lubrication oil sump G FEAD (Front End Accessory Drive) tensioner J Alternator and drive pulley assembly L Turbocharger B Cylinder head D Bedplate F Torsional vibration damper H Starter motor K Twin thermostat 15 - 11 9806/6900-3 15 - 11

15 - Engine 00 - General 00 - General Figure 9. Flywheel (rear) end G A F B E D C A Rocker cover C Flywheel E Timing case G Turbocharger B Cylinder head D Fuel injection pump gear access cover F Inlet manifold 15 - 12 9806/6900-3 15 - 12

15 - Engine 00 - General 00 - General Figure 10. 6 Cylinder mechanical engine (ISO) view M A L B C D H K E J F G A Inlet manifold C FEAD belt tensioner E Coolant pump drive pulley G Oil drain plug (sump) J Water inlet connector L Turbocharger J Coolant inlet connector B Oil cooler remote D Torsional vibration damper F Lubrication oil sump H Starter motor assembly K Alternator and drive pulley assembly M Fuel injector cover 15 - 13 9806/6900-3 15 - 13

15 - Engine 00 - General 00 - General Operation The Four Stroke Cycle The stages in the four stroke cycle for each cylinder are as follows: This section describes the cycle sequence, for the 6 cylinders of the diesel engine. Table 6. The Four Stroke Cycle Stage number 1 Piston operation The piston is at the top of its Com- pression stroke and is about to start its Power stroke. The piston is at the bottom of its Power stroke and is about to start its Exhaust stroke. The piston is at the bottom of its In- duction stroke and is about to start its Compression stroke. The piston is at the top of its Ex- haust stroke and is about to start its Induction stroke. Valve operation Inlet and exhaust valves closed. 2 Inlet valves closed, exhaust valves about to open. 3 Exhaust valves closed, inlet valves about to close. 4 Valve operation exhaust valves about to close, inlet valves about to open. Firing order Power A cylinder is said to be firing, when the fuel/air mixture ignites and the piston is about to start its power stroke. The piston continues to rise after the start of fuel injection causing a further increase in pressure and temperature. The temperature rises to a point at which the fuel/air mixture ignites. A cylinder is said to be firing, when the fuel/air mixture ignites. Four Stroke Cycle Induction This combustion causes a very rapid rise in both temperature and pressure. The high pressure generated propels the piston downward turning the crankshaft and producing energy. As the piston travels down the cylinder, it draws filtered air at atmospheric pressure and ambient temperature through an air filter and inlet valves into the cylinder. Exhaust Compression Once the piston has reached the bottom of its travel, the exhaust valves open and momentum stored in the flywheel forces the piston up the cylinder expelling the exhaust gases. When the piston reaches the bottom of its stroke the inlet valves close. The piston then starts to rise up the cylinder compressing the air trapped in the cylinder. This causes the temperature and pressure of the air to rise. Fuel is injected into the cylinder when the piston is near to top dead centre. In a running engine these four phases are continuously repeated. Each stroke is half a revolution of the crankshaft, thus, in one cycle of a four stroke engine, the crankshaft revolves twice. 15 - 14 9806/6900-3 15 - 14

15 - Engine 00 - General 00 - General Figure 11. 3 2 C B 4 1 746030 1 3 A C TDC Induction Power stroke Camshaft Camshaft lobe - Exhaust valve operation TDC (Top Dead Centre) 2 4 B BDC Bottom dead centre Compression stroke Exhaust stroke Camshaft lobe - Inlet valve operation 15 - 15 9806/6900-3 15 - 15

15 - Engine 00 - General 00 - General Figure 12. 717620 1 2 3 4 B C A A A A C B B C B C 1 Induction stroke 3 Power stroke A Camshaft C Camshaft lobe - Exhaust valve operation 2 Compression stroke 4 Exhaust stroke B Camshaft lobe - Inlet valve operation 15 - 16 9806/6900-3 15 - 16

15 - Engine 00 - General 00 - General Drain and Fill Clean Notice: Clean the engine before you start engine maintenance. Obey the correct procedures. Contamination of the fuel system will cause damage and possible failure of the engine. Notice: The engine and other components could be damaged by high pressure washing systems. Special precautions must be taken if the machine is to be washed using a high pressure system. Make sure that the alternator, starter motor and any other electrical components are shielded and not directly cleaned by the high pressure cleaning system. Do not aim the water jet directly at bearings, oil seals or the engine air induction system. Refer to Engine, Oil Filter, (PIL 15-21-00). Before carrying out any service procedures that require components to be removed, the engine must be properly cleaned. Cleaning must be carried out either in the area of components to be removed or, in the case of major work, or work on the fuel system, the whole engine and surrounding machine must be cleaned. Stop the engine and allow it to cool for at least one hour. DO NOT attempt to clean any part of the engine while it is running. 1. Make sure that the electrical system is isolated. 2. Make sure that all electrical connectors are correctly coupled. If connectors are open fit the correct caps or seal with water proof tape. 3. Cover the alternator with a plastic bag to prevent water ingress. 4. Seal the engine air intake, exhaust and breather system. 5. Make sure that the oil filler caps and dipstick are correctly installed. 6. Use a low pressure water jet and soft bristle brush to soak off caked mud or dirt. 7. Apply an approved cleaning and degreasing agent with a brush. Obey the manufacturers instructions. 8. Use a pressure washer to remove the soft dirt and oil. Important: DO NOT aim the water jet directly at oil seals or electrical and alternator. DO NOT place the jet nozzle closer than 600mm (24 in) to any part of the engine. 9. When the pressure washing is complete move the machine away from the wash area, or alternatively, clean away the material washed from the machine. 15 - 26 9806/6900-3 15 - 26

15 - Engine 00 - General 00 - General 10. Before working on specific areas of the engine use a compressed air jet to dry off any moisture. When the area is dry use a soft clean brush to remove any sand or grit particles that remain. 11. When removing components be aware of any dirt or debris that may be exposed. Cover any open ports and clean away the deposits before proceeding Additional cleaning must be carried out prior to working on the high pressure fuel system, refer to: Fuel System - Clean (PIL 18-00). 15 - 27 9806/6900-3 15 - 27

15 - Engine 00 - General 00 - General Check (Pressure) Engine Compression Test rotating in the engine compartment.Before starting this job make sure that you have no loose clothing (cuffs, ties etc) which could get caught in rotating parts.When the engine is turning, keep clear of rotating parts. This test is used to diagnose suspected poor compression in one or more of the engine cylinders. Use ServiceMaster to control the test. 1. To bleed the injectors you must turn the engine. Several factors can influence the compression pressure, the following conditions are assumed: 2. Get access to the engine. The valve clearances have been set correctly. Refer to (PIL 15-30). 3. Remove all six fuel injectors. Refer to (PIL 18-18). The correct engine oil has been used. Refer to (PIL 75-03). The engine oil level is correct. Refer to (PIL 15-21). 3.1. Make sure that the injectors are labelled for correct installation at a later stage. 4. Install the dummy injector in one of the vacant cylinder injector bores. Refer to Figure 13. The correct type of diesel fuel has been used and the system correctly primed, refer to (PIL 75-18). The battery and starting circuit is fully charged and in good condition, e.g. good earth paths, cable connections tight etc. 5. Install the dummy injector in one of the vacant cylinder injector bores. 5.1. Note: The dummy injector is drilled and tapped 1/8-28 BSP x 8 mm deep to accept a standard pressure gauge fitting. When comparing the figures recorded in the following procedures, there should be a minimum variation of 3.5 bar (50.7psi) between each cylinder. If the variation is greater than this figure, then remove the cylinder head, refer to (PIL 15-21) and closely inspect the cylinder bores, pistons and piston rings for signs of wear or damage. Repair as necessary. 6. Operate the starter motor to crank the engine. 6.1. Do not crank for longer than 20 seconds. 6.2. Record the gauge reading. 7. Do steps 3 to 6 again for the remaining five cylinders. WARNING! To bleed the injectors you must turn the engine. When the engine is turning, there are parts 15 - 28 9806/6900-3 15 - 28

15 - Engine 00 - General 00 - General Figure 13. 0 50 0 0 50 50 A A Dummy Injector 15 - 29 9806/6900-3 15 - 29

15 - Engine 00 - General 00 - General Remove and Install Special Tools Description Lifting Bracket Front Lifting Bracket Front Engine Lifting Spreader Bar recommended lifting equipment is shown. Use a spreader bar when lifting the engine. Never attempt to manually lift heavy components on your own. Always use lifting equipment, or obtain the help of an assistant. Inspect the lifting brackets for signs of damage. The brackets must be correctly torqued to the crankcase. Make sure the lifting equipment does not damage any of the engine dressing and the rocker cover. Part No. 320/09425 320/09426 892/01382 Qty. 1 1 1 Lifting Equipment You can be injured if you use incorrect or faulty lifting equipment. You must identify the weight of the item to be lifted then choose lifting equipment that is strong enough and suitable for the job. Make sure that lifting equipment is in good condition and complies with all local regulations. Component Identification The following component identification is for a typical engine installation. There will be some component differences depending on the machine variant. Before attempting to remove the engine ensure that all the necessary components have either been removed, or safely disconnected from the engine. The lifting equipment used must be an approved type and capable of lifting the engine safely. The 15 - 30 9806/6900-3 15 - 30

15 - Engine 00 - General 00 - General Figure 14. G H B A A C F D E J M L K A Lifting brackets C Electrical connections - alternator E Electrical earth connection - starter motor G Coolant port - heater hose B Exhaust port - turbocharger D Electrical connector - oil level switch F Electrical connections - starter motor H Electrical connector - coolant temperature sensor K Fuel line connections - fuel injection pump M Ports - remote oil cooler hoses J Throttle cable connection - fuel injection pump L Electrical connector - oil pressure sensor 15 - 31 9806/6900-3 15 - 31

15 - Engine 00 - General 00 - General Remove converter clear of the engine, make sure that the torque converter stays mounted on the gearbox shaft. 1. Make sure that the engine is safe to work on. If the engine has been running, let it cool before you start the service work. 22. Attach slings to the engine lifting eyes. Install the engine lifting spreader bar. Special Tool: Lifting Bracket Front (Qty.: 1) Special Tool: Lifting Bracket Front (Qty.: 1) Special Tool: Engine Lifting Spreader Bar (Qty.: 1) 2. Position the machine on firm level ground. Make the machine safe. Refer to (PIL 01-03). 3. Discharge the hydraulic pressure. Refer to (PIL 30-00). 23. Take the weight of the engine on the hoist and remove the engine mounting bolts. 4. Get access to the engine. 5. Disconnect the battery. Refer to (PIL 33-03). 24. Withdraw the engine in a level attitude until the hydraulic pump is clear of the chassis. Raise the engine to lift it clear of the machine. 6. Drain the engine oil. Refer to (PIL 15-21) 7. Drain the engine coolant. If necessary remove the cooling pack refer to (PIL 21-03). 25. Lower the engine into a suitable stand that is capable of supporting the weight of the engine. 8. If applicable, drain the hydraulic tank. Disconnect and plug the hydraulic suction and delivery lines at the engine driven hydraulic pumps. Label the hoses to ensure correct reassembly. Figure 15. C 9. Disconnect the throttle cable at the fuel injection pump. 10. If applicable, disconnect and plug the remote oil filter hoses at the oil cooler housing. Label the hoses to ensure correct reassembly 11. Disconnect the exhaust system. 12. Label the cab heater hose at the cylinder head. Release the hose clip and remove the hose. B 13. Disconnect the wiring connections from the starter motor. Refer to (PIL 15-75) 14. Disconnect the wiring connections from the alternator. Refer to (PIL 15-72) 15. Disconnect the wiring connections from the engine sensors and actuators. Refer to (PIL 15-84). 16. Disconnect the electrical connector at the oil level sensor (if installed). A 17. Disconnect the fuel supply line at the fuel lift pump and the spill line at the fuel injection pump. Cap all hoses and ports to prevent ingress of dirt. 18. Ensure that all relevant harnesses and hoses are unclipped from the engine and tied out of the way. 19. If applicable disconnect and plug the hoses at the hydraulic pump. A Lifting bracket mounting bolts B Spreader bar C Lifting equipment 20. If applicable disconnect the electrical connectors at the hydraulic pump. 21. If applicable remove the gearbox to engine retaining bolts, move the gearbox and torque 15 - 32 9806/6900-3 15 - 32

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15 - Engine 00 - General 00 - General Install 1. Replacement is a reversal of the removal procedure. 2. On engines with a torque converter it is vitally important that the torque converter is installed at the gearbox and engine flywheel correctly. Failure to locate the converter correctly will result in damage to the gearbox oil pump on engine start up. 3. Fill the cooling system with the correct mix of coolant fluid. 4. Fill and check the hydraulic fluid level. 5. Fill and check the engine oil level. 6. On completion, check the hydraulic and cooling system for leakage and levels. Table 26. Torque Values Item A Nm 47 15 - 33 9806/6900-3 15 - 33

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