7B ENGINE SERVICE–543 LOADER (ISUZU)

from Bobcat 540 543 Loader Service Manual 6566181 (6-12) - PDF DOWNLOAD

7A ENGINE SERVICE–540 LOADER (KOHLER)

7B–1 TROUBLESHOOTING

The following troubleshooting chart is provided as an assistance in locating and correcting problems which are most common. Many of the recommended procedures must be done by authorized Bobcat Service Personnel only.

Problem Cause

7B–1 TROUBLESHOOTING (Cont’d)

1.Battery capacity low.

2.Bad electrical connection.

3.Faulty starter motor.

4.Incorrect grade of oil.

5.Low cranking speed.

6.Fuel tank empty.

Key To Correct The Cause

29.Sticking valves.

30.Incorrect high pressure tubelines.

31.Worn cylinder bores.

32.Worn valves and seats.

33.Broken, worn or sticking piston rings.

34.Worn valve stems and guides.

7.Faulty stop control operation.

8.Plugged fuel line.

9.Faulty fuel lift pump.

10.Plugged fuel filter.

11.Restriction in the air cleaner.

12.Air in the fuel system.

13.Faulty fuel injection pump.

14.Faulty fuel injectors.

15.Incorrect use of the glow plugs.

16.Faulty glow plugs.

17.Broken fuel injection pump drive.

18.Incorrect fuel pump timing.

19.Incorrect valve timing.

20.Poor compression.

21.Plugged fuel tank vent.

22.Incorrect type or grade of fuel.

23.Sticking or restricted throttle.

24.Exhaust pipe restriction.

25.Cylinder head gasket leaking.

26.Overheating.

27.Cold running.

28.Incorrect valve tappet adjustment.

35.Worn or damaged bearings.

36.Not enough oil in the oil pan.

37.Gauge is not correct.

38.Oil pump is worn.

39.Pressure relief valve is open.

40.Pressure relief valve is sticking closed.

41.Broken relief valve spring.

42.Faulty suction valve.

43.Plugged oil filter.

44.Piston seizure.

45.Incorrect piston height.

46.Damaged fan.

47.Faulty engine mounting.

48.Faulty thermostat.

49.Restriction in the water jacket.

50.Plugged radiator.

51.Faulty water pump.

52.Plugged breather pipe.

53.Valve stem seals damaged.

54.Coolant level is low.

55.Plugged oil pump pipe screen.

56.Broken valve spring.

7B–2 FUEL SYSTEM

7B–2.1 Fuel Filter

The fuel filter is located on the left side of the engine (Fig. 7B–1). To replace the fuel filter, use the following procedure:

1.Close the shut–off valve at the fuel tank (Fig. 7B–2).

2.Remove the fuel filter element (Fig. 7B–1) by turning it counterclockwise.

3.Clean the filter housing where the element makes contact.

4.Put oil on the gasket of the fuel filter element.

5.Install the fuel filter element and hand tighten only.

6.Open the shut–off valve at the fuel tank (Fig. 7B–2).

7.Remove the air from the fuel system.

7B–2.2 Removing the Air from the Fuel System

1.Loosen the vent plug at the fuel injection pump (Fig. 7B–3).

2.Engage the starter and turn the engine until solid fuel flows from the vent port with no air bubbles.

3.Stop turning the engine. Tighten the vent plug.

4.Loosen the fittings at the fuel injectors (Fig. 7B–4).

5.Put the throttle at 1/2 open position.

6.Turn the engine with the starter until solid fuel flows from the high pressure tubeline fittings.

7.Tighten the high pressure tubeline fittings at the fuel injectors (Fig. 7B–4).

7B–2.3 Fuel Lift Pump

The fuel lift pump is located on the side of the injection pump (Fig. 7B–5). The lift pump can not be repaired. It is replaced as a complete assembly.

1.Disconnect the fuel lines to the lift pump.

2.Remove the bolts and remove the fuel lift pump.

3.Install a new gasket and the fuel lift pump.

4.Install the bolts and tighten.

5.Connect the fuel lines.

7B–2.4 Removal of the Fuel Injection Pump

The injection pump contains parts which have a very close tolerance and its operation has a direct effect on the performance of the engine.

Important

1.Remove the high pressure tubelines from the injection pump (Fig. 7B–6).

2.Remove the fuel lines to the injection pump (Fig. 7B–7).

3.Disconnect the fuel lines from the fuel pump (Fig. 7B–8).

4.Disconnect the return spring at the fuel injection pump (Fig. 7B–9).

5.Disconnect the throttle linkage.

6.Remove the six (6) bolts which hold the injection pump to the timing cover (Fig. 7B–10).

7.Remove the injection pump (Fig. 7B–11) from the engine.

If you do not have the correct equipment and trained personnel, adjustment or maintenance must not be done.

7B–2.5 Fuel Injection Pump Drive Gear

1.Remove the nut and lockwasher from the injection pump shaft (Fig. 7B–12).

2.Use a puller to remove the gear.

3.To install the gear, install the key and make alignment of the key with the keyway in the gear and install the gear on the injection pump shaft.

4.Install the lockwasher and nut.

5.Tighten the nut to 40 ft.–lbs. (54 Nm) torque.

7B–2.6 Installation and Timing of the Fuel Injection Pump

1.Remove the cover on the timing case.

2.Turn the engine so that the “Z” mark on the gear can be seen in the hole in the timing case (Fig. 7B–13).

3.Install the injection pump.Make sure the “Z” mark on the injection pump gear is in correct alignment with the “Z” mark of the drive gear (Fig. 7B–13).

4.Install the six (6) mounting bolts (in the timing case) and tighten to 12 ft.–lbs. (16 Nm) torque.

5.Install the cover over the hole in the timing case.

6.Check the timing mark on the injection pump flange (Fig. 7B–14). If the timing marks are not in alignment, loosen the three (3) bolts (Fig. 7B–15) and make alignment of the timing marks (Fig. 7B–14).

7.Connect the throttle to the injection pump.

8.Connect the return spring (Fig. 7B–9).

9.Connect the fuel lines at the fuel lift pump (Fig. 7B–8).

10.Install the fuel line at the injection pump (Fig. 7B–7).

Important

If you do not have the correct equipment and trained personnel, adjustment or maintenance must not be done.

11.Connect and tighten the high pressure tubelines (Fig. 7B–6).

7B–2.7 Fuel Injection Pump Reservoir

The oil in the reservoir must be checked every 100 hours of operation.

To check the level in the reservoir, use the following procedure:

1.Remove the check plug (Fig. 7B–16) at the side of the fuel injection pump.

B–05226

2.If no oil can be seen at the port, remove the breather on the top of the fuel injection pump (Fig. 7B–17).

3.Add the same type of oil that is being used in the engine (See the Oil Specifications Chart in Section 1). Add oil until it flows from the check port.

4.Install the plug (Fig. 7B–16) and tighten.

7B–2.8 Fuel Injector Nozzles

Warning

Diesel fuel under pressure can have enough force to penetrate the skin. Check to be sure all connections are tight and the lines, pipes and hoses are not damaged before you disconnect any lines. Often you cannot see fuel leakage from a small hole. Use a piece of cardboard or wood to find leakage. See a doctor immediately if you get injured from diesel fuel. Serious problems can result if you do not get immediate medical attention.

These are some of the engine problems caused by injector nozzles which have a defect:

1.The engine is hard to start or will not start.

2.Rough engine operation.

3.The engine will not idle correctly.

4.The engine will not have full power.

5.The engine exhaust smoke is black, white or blue.

Remove the injector nozzles from the engine and test them only after the engine performance shows a defect.

Removing the Fuel Injector Nozzles

1.Remove the fuel return lines from the injector nozzles (Fig. 7B–19).

2.Remove the high pressure tubelines (Fig. 7B–20).

5.Remove the fuel injector nozzle from the engine (Fig. 7B–21).

Important

Checking the Fuel Injector Nozzles

Do not disassemble or test the injector nozzles unless you have the correct service and testing tools.

The tools listed will be needed to do the following procedure:

MEL–10018 – Injection Nozzle Tester

MEL–10019 – Accessory Set

1.Connect the injector nozzle to the tester with the nozzle in a down position (Fig. 7B–22).

2.Slowly operate the hand lever of the test pump until the injector nozzle valve opens. The working pressure for the nozzle is as listed:

(a)Working Pressure 0 1707 PSI (11770 kPa)

3.If the pressure is not correct, clean and adjust the nozzle.

4.Check for inside leakage. Operate the hand lever until the pressure is almost enough to open the injector valve. Make a record of the pressure.

5.Release the hand lever. Check the pressure decrease for six (6) seconds. The injector nozzle has a defect if the pressure decrease is more than 740 PSI (5162 kPa) in the six (6) seconds.

Warning

Keep away from fuel coming from the nozzles. Wear eye protection.

6.Check the spray pattern of the nozzle for the following conditions (Fig. 7B–23):

(a)Does not come out the side of the nozzle.

(b)Does not have drops coming from the nozzle.

(c)Does not have a flow (solid stream) coming from the nozzle.

Any of the above conditions show a defect or a dirty injector nozzle. Clean the nozzle and make the test again. Replace the injector nozzle that does not operate correctly after they have been cleaned.

Disassembly of the Fuel Injector Nozzle

1.Fasten the body of the nozzle holder (Fig. 7B–24, Item 1) in a vise and remove the cap nut (Item 2), be careful not to put a scratch on the nozzle holder.

2.Remove the nut and adjustment bolt (Fig. 7B–24), Items 3 & 4) and take out the washers (Item 5), nozzle spring (Item 6) and the push rod (Item 7).

3.Remove the nozzle nut (Fig. 7B–24, Item 8) and take out the nozzle assembly (Item 9), then remove the bushing (Item 10). Keep the nozzle assembly in clean diesel fuel.

4.Remove the inlet connector assembly (Fig. 7B–24, Item 11) together with the gasket (Item 12) and take out the edge filter (Item 13).

Inspection of the Fuel Injector Nozzle

1.Wash the needle valve and nozzle body in the clean solvent. Tilt the body to an angle of 60 ° from vertical and check that the needle valve slides out smoothly. If the needle valve is not free or if its sliding movement is very loose, replace the nozzle assembly.

(a)Check the seat area and the tip of the needle valve for wear. Replace the nozzle if it is worn.

2.Nozzle holders.

(a)Check the thread areas of the nozzle holders for wear or damage. Replace nozzle assembly if a defect is found.

(b)Check the nozzle springs for weak condition, corrosion or damage.

(c)Check the push–rods for bending and the surface in contact with the needle valve for wear and magnet effect.

(d)Check the upper surface and needle valve seat on the nozzle body for wear or scratch marks.

Assembling the Fuel Injectors Nozzle

Assemble the fuel injector nozzle in the reverse order of disassembly and make note of the following items.

1.Wipe and clean the contact areas of the nozzle and body of the nozzle holders to remove any oil. Install the nozzle into the body of the nozzle holder and tighten the nozzle nut.

2.Install new gaskets at the time of assembly.

1.Install the fuel injector nozzle in the engine cylinder head. Make sure to install the washer under the nozzle tip (Fig. 7B–25).

2.Tighten the fuel injector nozzle (Fig. 7B–26).

3.Install the high pressure tubelines and tighten (Fig. 7B–27).

4.Install the return lines on the fuel injector nozzles (Fig. 7B–28).

1.Remove all the bolts from around the outside edge of the blower housing (Fig. 7B–29).

2.Remove the nut from the bolt that holds the wiper in position (Fig. 7B–30).

3.Remove

4.Remove

5.Remove

6.Remove

9.Remove the mounting plate from the engine (Fig. 7B–37).

7B–3.2 Removing the Engine

Lift the loader and put jackstands under the loader frame so there is no danger of the loader falling and causing personal injury.

1.Raise the operator guard (See Paragraph 5–1.1, Page 5–1).

2.Remove the rear door (See Paragraph 5–4, Page 5–9).

3.Remove the battery from the loader (See Paragraph 6–3.1, Page 6–3).

4.Remove the blower housing (See Paragraph 7B–3.1).

5.Disconnect the engine wiring harness.

6.Disconnect the wires from the alternator.

7.Disconnect the ground wire at the right side of the engine.

8.Remove the bolts which hold the hydrostatic pumps and engine together.

9.Disconnect the throttle linkage at the injection pump.

10.Remove the radiator hose at the radiator (Fig. 7B–38) and remove the coolant from the system.

11.Loosen the clamps on the radiator hose and remove the hose from the thermostat housing and radiator (Fig. 7B–39).

12.Remove the support brackets (both sides) from the radiator air shrouding (Fig. 7B–40).

13.Remove the plate (Fig. 7B–41, Item 1) from the air shrouding and remove the air shrouding from the engine (Fig. 7B–41).

14.Remove the clamp at the exhaust pipe (Fig. 7B–42).

15.Remove the exhaust pipe from the muffler and from the loader (Fig. 7B–43).

16.Remove the air cleaner hose (Fig. 7B–44).

17.Disconnect the fuel return line (Fig. 7B–45).

18.Remove the bolts from the engine mounting brackets (both sides) (Fig. 7B–46).

19.Install an engine removal table (Fig. 7B–47, Item 1) at the rear of the loader.

20.Slide the engine toward the rear of the loader and on the table (Fig. 7B–47).

7B–3.3 Installing the Engine

1.Slide the engine into the rear of the loader until the engine makes contact with the hydrostatic pump coupler.

2.Make alignment of the engine splines to the coupler and slide the engine into the correct location.

3.Remove the engine removal table (Fig. 7B–47, Item 1).

4.Install the bolts in the engine mounting brackets and tighten to 65–70 ft.–lbs. (88–95 Nm) torque.

5.Connect the fuel line (Fig. 7B–45).

6.Install the air cleaner hose (Fig. 7B–44) and tighten the clamps.

7.Install the exhaust into the loader and on the muffler (Fig. 7B–43).

8.Tighten the exhaust pipe clamp (Fig. 7B–42).

9.Install the air shrouding in the loader and install theplate in the air shrouding (Fig. 7B–41).

10.Install the support brackets and tighten the bolts (both sides) (Fig. 7B–40).

11.Install the radiator hose on the thermostat housing and the radiator (Fig. 7B–39) and tighten the clamps.

12.Install the other radiator hose to the radiator and tighten the clamp (Fig. 7B–38).

13.Connect the throttle linkage to the fuel injection pump.

14.Install the bolts which hold the hydrostatic pump and engine together and tighten to 65–70 ft.–lbs. (88–95 Nm) torque.

15.Connect the ground wire, alternator wires and the engine harnessconnector.

16.Install the blower housing (See Paragraph 7B–3.4).

17.Install the battery (See Paragraph 6–3.3, Page 6–4).

18.Install the rear door (See Paragraph 5–4, Page 5–9).

19.Lower the operator guard (See Paragraph 5–1.2, Page 5–1).

20.Remove the jackstands from under the loader frame.

7B–3.4.Installing the Blower Housing

1.Install the mounting plate on the engine (7B–48).

2.Install the bolt for the mounting plate at the right side of the engine and tighten (Fig. 7B–49).

3.Install the bolts and nuts for the mounting plate and tighten.

4.Install the blower fan on the crankshaft sheave (Fig. 7B–51).

5.Install the bolts in the blower fan and tighten (Fig. 7B–52).

3.Remove the radiator hose from the radiator and remove the coolant (Fig. 7B–58).

4.Remove the radiator hose from the thermostat housing and the radiator (Fig. 7B–59).

5.Remove the support brackets (both sides) from the radiator air shrouding (Fig. 7B–60).

6.Remove the plate (Fig. 7B–61, Item 1) from the air shrouding and remove the air shrouding from the engine (Fig. 7B–61).

7.Loosen the exhaust pipe clamp and remove the exhaust pipe from the muffler and the loader (Fig. 7B–62).

8.Remove the bolts (both sides) for the radiator mounting plate (Fig. 7B–63).

9.Remove the nuts (both sides) at the front of the radiator mounting plate (Fig. 7B–64).

10.Remove the bolts (both sides) at the front of the radiator and the mounting plate (Fig. 7B–65).

11.Pull the mounting plate and the radiator assembly down until it makes contact with the engine.

12.Lift the radiator up and out of the mounting plate (Fig. 7B–66).

7B–3.6 Installation of the Radiator

1.Install the radiator on the mounting plate (Fig. 7B–66).

2.Push the radiator and mounting plate assembly up into position. Make sure the holes are in correct alignment.

3.Install the mounting plate bolts (one on each side) and the nuts (one on each side at the front) and tighten (Fig. 7B–63 & 7B–64).

4.Install the radiator mounting bolts and tighten (Fig. 7B–65).

5.Install the exhaust pipe in the loader and on the muffler and tighten the clamp (Fig. 7B–62).

6.Install the air shrouding in the loader and the plate on the air shrouding (Fig. 7B–61).

7.Install the support brackets for the air shrouding and tighten the bolts (Fig. 7B–60).

8.Install the radiator hose on the thermostat housing and the radiator and tighten the clamps (Fig. 7B–59).

9.Install the radiator hose on the other side and tighten the clamp.

10.Install the blower housing (See Paragraph 7B–3.4).

11.Put the correct amount of coolant in the radiator (See Section 8 for capacity) and install the radiator (Fig. 7B–57).

7B–4 ENGINE OVERHAUL

7B–4.1 Disassembly of the Engine

1.Remove the engine from the loader (See Paragraph 7B–3.2).

2.Remove the fuel injection pump (See Paragraph 7B–2.4) (Fig. 7B–67).

3.Remove the bolts which hold the fuel filter and remove the fuel filter assembly.

4.Remove the fuel injectors nozzles (See Paragraph 7B–2.8).

5.Remove the oil filter assembly and disconnect the tubelines that goes to the rocker arm shaft for oil pressure.

6.Remove the sender switch for the oil pressure.

7.Remove the bolts for the adjustment and lower mounting bracket and remove the alternator.

8.Remove the bolts that hold the starter and remove the starter from the engine.

9.Remove the muffler and manifold assembly.

10.Remove the bolts which hold the water pump and remove the water pump.

11.Bend the washer on the bolt for the crankshaft sheave.

12.Remove the crankcase and oil pan together. If the crankcase will not separate from the block, use a screwdriver and pry them apart (Fig. 7B–70).

13.Remove the timing gear cover.

14.Remove the idler gear.

15.Remove the valve cover.

16.Remove the rocker arm assembly from the engine (Fig. 7B–69).

NOTE:Turn each bolt in the rocker arm assembly 1/4 turn until all the bolts are loose.

17.Remove the push rods from the engine.

NOTE:Turn each bolt in the cylinder head 1/4 turn at a time until all thebolts are loose.

18.Remove the cylinder head and gasket.

19.Remove the crankcase and oil pan together. If the crankcase will not separate from the block, use a screwdriver and pry them apart (Fig. 7B–70).

20.Disconnect the pipe at the connection on the cylinder body side.

21.Remove the bolts and remove the oil pump assembly from the engine block.

22.Remove the bolts from the thrust plate of the camshaft and remove the camshaft (Fig. 7B–71).

NOTE:Be careful not to scratch the camshaft bearings.

23.Remove the front plate fromthe engine.

24.Use a magnetic tool to remove the tappets from the engine block (Fig. 7B–72).

NOTE:Remove the carbon from the upper part of the cylinder wall before removing the piston and rod assembly.

25.Mark each piston so it will be returned to its original location when being assembled.

26.Remove the connecting rod caps and push the piston and rod assembly through the top of the engine block (Fig. 7B–73).

27.Remove the flywheel (See Paragraph 7B–16.1, Page 7B–33).

28.Mark the main bearing caps so that each will be installed in the correct location.

NOTE:Do not cause damage to the oil seal in the cap for the rear main bearing.

29.Remove the main bearing caps and bearings.

30.Remove the thrust washers and the crankshaft (Fig. 7B–74).

31.Wash and clean all the parts to remove dirt, carbon, oil, grease or rust.

32.Inspect the cylinder body and the cylinder head for damage.

33.Clean all the oil openings with compressed air and check that each opening has no restriction.

34.Remove the carbon from the pistons, cylinder head and valves.

7B–5 ROCKER ARMS AND SHAFT

7B–5.1 Disassembly of the Rocker Arms

1.Remove the snap ring from each end of the rocker arm shaft.

2.Remove the springs, rocker arms, rocker shaft bracket and rocker shaft (Fig. 7B–75).

3.Keep all parts in correct order for correct assembly.

4.Assemble the parts in the reverse order of disassembly.

7B–5.2 Inspection of the Rocker Arms

1.Measure the outside diameter of the rocker shaft with a micrometer (Fig. 7B–76).

2.Replace the rocker shaft if measurement is over the limit (See Section 8 for specifications).

3.Measure the inside diameter of the bushings with a micrometer. Install new bushings if the measurements are over the limit (Fig. 7B–77).

4.Check the wear of the face of the rocker arms that are in contact with the valve stem. Replace the rocker arms if the amount of wear is over maximum. Remove the small scratch marks on the face of the rocker, by grinding (Fig. 7B–78).

7B–6 CYLINDER HEAD

7B–6.1 Disassembly of the Cylinder Head

1.Disconnect the glow plug wiring at the connectors and removethe glow plugs from the cylinder head.

2.Mark the valves so that each will be installed in their original location.

3.Use a valve spring compressor to remove the valve springs and remove the split collar, valve springs and valve (Fig. 7B–79).

4.Remove the valve seals from the valve guides.

5.Use a tool to force the valve guides out toward the bottom of the cylinder head (Fig. 7B–80).

NOTE:If the hot plugs are to be removed, do steps 6 through 8.

6.Put a cylinder number on each of the hot plugs.

7.Put a 1/4” (5–7 mm) diameter rod into the nozzle hole in the cylinder head. Use a hammer to force the hot plug out (Fig. 7B–81).

NOTE:Hold the rod so that it is against the upper edge of the hole with threads, as shown in figure 7B–81.

8.Do not hit the hot plug with the rod, or damage to the heat shield can result.

7B–6.2 Inspection of the Cylinder Head

1.Carefully remove carbon from the bottom of the cylinder head (Fig. 7B–82). Check the cylinder head for cracks and damage.

NOTE:When removing carbon from the bottom of the cylinder head, be careful not to scratch the valve seat area.

2.Check the lower surface of the cylinder head for distortion, in six (6) directions, using a straight edge and a feeler gauge. If the amount of the distortion is more than 0.008” (0,2 mm), correct by grinding, so that the maximum amount of distortion is within 0.0012” (0,05 mm).

3.Check the joining face of the intake and exhaust manifolds for distortion, using the same method as for checking the cylinder head. If the amount of distortion is more than 0.016” (0,4 mm), correct by grinding so that maximum amount of distortion is within 0.0012” (0,05 mm).

7B–6.3 Inspection of the Combustion Chambers

1.Remove all the carbon from the combustion chambers. Check the heat shield and hot plug holes in the combustion chamber, for damage.

2.Check the hot plug fitting areas for cracks and damage and make replacement of the cylinder head assembly if there is any damage condition to the cylinder head. High spots or pieces on the hotplug seat can cause poor fitting of the hot plug.

7B–6.4 Inspection and Correction of the Valves & Guides

1.Check the amount of wear of the valve stems in the valve guides (Fig. 7B–83).

2.Use a micrometer to measure the outside diameter of the valve stem at locations “A”, “B” & “C” (Fig. 7B–84).

3.Check the valve seats for the wrong contact or damage and correct or replace as needed. Before correcting the valve seat, check the valve guide and install a new guide as necessary.

4.Cut the valve seat using a seat cutter of the correct specifications so that the contact width is correct (Fig. 7B–85 & 7B–86).

NOTE:When cutting the valve seat use a guide rod of the correct diameter.

5.If the amount of valve seat depth is over the limit for being repaired, replace the valve seat insert (Fig. 7B–87).

6.Use the following procedure for replacement of the valve seat insert:

(a)Use a torch to heat the opposed two (2) sides of the inner face of the valve seat red hot. Let the insert cool for 3–5 minutes. Use a screwdriver to remove the valve seat insert.

PI–2095

Contact Width

PI–02098

PI–02092

7.Press the insert all the way into the insert bore. Then grind the seat face.

8.Check the head and stem of the intake and exhaust valves for wear and distortion and replace as needed. Also check and install new valves if the thickness of the valve head is less than the limit (Fig. 7B–88).

Thickness of Valve Head

PI–02101

Fig. 7B–88 Checking New Valve

9.Use a valve grinder to correct the seat face of the valves to an angle of45° Correct the valve stem end as needed.

10.Put valve grinding compound on the seat face of the valve and use a grinding tool to check the valve face to seat contact.

NOTE:Contact width which is too wide will cause carbon deposits between valve and seat. Contact width which is too narrow will increase the wear of the parts.

B–02851

Fig. 7B–89 Grinding Valve Seat

7B–6.5 Inspection of the Valve Springs

1.Make a visual check of the valve springs for damage. Put the valve springs on a surface plate and check the amount of deviation of the valve spring from vertical, using a square. Install a new spring if the amount of deviation from vertical is over the limit (Fig. 7B–90).

2.Check the tension of the valve springs with a spring tester. Install new valve springs if the measured value is over the limit (Fig. 7B–91).

7B–6.6 Inspection of the Push Rods and Tappets

1.Check the push rods for wear or bending. Replace worn orbend push rods.

2.Check the face of the tappets in contactwith the push rods for wear. Replace any tappets which have a defect.

3.Measure the outside diameter of the tappets with a micrometer. Install new tappets if the amount of reduction in the outside diameter is over the limit (Fig. 7B–92).

7B–6.7 Installation of the Hot Plugs

1.Align the round part of the hot plug with a groove in the cylinder head and install the hot plug into position by hitting the circumference of the hot plug carefully with a brass hammer.

2.Hold a soft metal plate with smooth surface on the hot plug to protect the face of the hot plug from damage.

3.Use a hydraulic press to press the hot plug fully into position slowly.

4.After the new hot plug has been installed, grind the end of the hot plug until it is even with the cylinder head face (Fig. 7B–93).

7B–6.8 Assembly of the Valve System

1.Push the valve guide into position from the upper face of the cylinder head (Fig. 7B–94 & 7B–95).

2.Install the oil seal on the valve guide.

NOTE:Install the oil seal carefully, to prevent damage.

3.Install the valve springs and valve spring seat.

4.Compress the valve springs with the valve spring compressor and install the locks for the valve stem.

5.Install the manifold gasket and the manifold assembly.

7B–7 CYLINDER BLOCK

7B–7.1

Inspection

of the Cylinder Block

1.Check the cylinder block for cracks by magnetic or red color method (Fig. 7B–96).

2.Check the distortion of the cylinder block surface using the following specifications:

(a)Standard ValveBelow 0.002” (0,05 mm)

(b)Valve for Need of Servicing Below 0.008” (0,2 mm)

7B–7.2 Correction of the Cylinder Bores

1.Use a cylinder bore gauge to measure the cylinderbore at the upper, middle and lower locations of the cylinder in two directions: (1) In line with the crankshaft; and (2) At a right angle to the crankshaft.

2.Cut the cylinders to oversize if the amount of wear is over the standard valve, or if the cylinder wall is damaged.

3.When the measurements are taken, find the piston oversize according to the largest bore diameter. Use a micrometer to measure the outside diameter of the pistons at the base, in the direction of the side thrust, at normal room temperature.

4.To find the bore diameter needed for hone operation, use the following formula:

Cylinder bore diameter after hone operation=P+C–H+E

P:Piston outside diameter

C:Piston clearance

H:Amount for hone operation

E:Error in bore finish

5.Measure the cylinder bore diameter after hone operation is complete.

NOTE:Cylinder bores, after hone operation, must be held within 0.008” (0,02 mm) of each other.

7B–8 PISTONS AND PISTON RINGS

7B–8.1 Disassembly of the Piston and Rings

1.Use a piston ring expander tool to remove the piston rings from the piston.

2.Use a snap ring pliers to remove the piston pin snap ring (Fig. 7B–97).

3.Heat the piston to 120 °–140°F. (50–60°C.) and remove the piston pin (Fig. 7B–98).

NOTE:Keep the piston, piston pin and connecting rod from each cylinder in separate groups in the sequence of the cylinder numbers, make sure that they are installed in their original locations.

Fig. 7B–97 Piston Snap Ring

7B–8.2 Inspection of the Pistons

Fig. 7B–98 Removing Piston Pin B–03012

A–02530

1.Make a visual check of the pistons for scratches, cracks or seizure and replace any found to have a defect.

2.Use an outside micrometer to measure the outside diameter of the pistons at the base, at a right angle to the piston pin hole. Measure the cylinderbore diameter at the base of the piston with a cylinder bore gauge. Then, compare the measured values to find the piston clearance. The standard clearance is 0.004”–0.005” (0,104–0,124 mm).

NOTE:When installing new piston rings on the pistons without cutting new cylinder sizes, measure the piston ring gaps with the piston rings held at the lower point of the cylinder (Fig. 7B–99).

3.Use a feeler gauge to measure the clearance between the piston ring and the ring groove in the piston. Take a measurement at several locations around the circumference of the piston (Fig. 7B–100).

7B–8.3 Inspection of the Connecting Rods & Bearings

1.Check the connecting rods for bending, distortion and damage.

2.Check for alignment between the big and the small end (Fig. 7B–101).

3.If the amount of wrong alignment or distortion is over the value limit for servicing, correct or replace the connecting rod.

4.The normal clearance between the piston and the small end bushing is such that the lubricated piston pin can be pushed into the bushing with finger pressure. Replace either the piston pin or bushing if the pin fits too loosely into the bushing.

Fig. 7B–99 Piston Ring Gap

A–02519

Fig. 7B–101 Connecting Rod Alignment

5.Assemble the connecting rod on the crankshaft and use a feeler gauge to measure the side clearance between the connecting rod big end and the crankpin (Fig. 7B–102). Replace the connecting rod if the clearance is over the limit.

Standard Clearance

0.008–0.010” (0,2–0,25 mm)

Limit for Use Above 0.014” (0,35 mm)

6.When a new bushing is fitted into the connecting rod small end, make the inner face smooth with a reaming tool according to the piston pin diameter.

7.When installing a new connecting rod, piston or piston pin, measure the weight of the replacement parts. Make necessary adjustment by grinding or selection of parts so that the weight of each piston and connecting rod assembly is held within 15 grams of each other (Fig. 7B–103).

7B–8.4 Assembly of the Piston & Connecting Rod

1.Heat the piston to about 190–250 °F. (70–120°C.) Align the small end hole of the connecting rod with the piston pin hole and install the piston pin.

NOTE:Assemble the connecting rod with the piston so that the side of the connecting rod with the cylinder number mark is toward the camshaft side of the engine.

2.Install the snap rings.

3.Use a ring expanding tool to assemble the piston rings on the piston (Fig. 7B–104).

NOTE:The first compression ring is chamfered. Install the third compression ring with the under cut side down. Install the first oil ring to the piston with the expander ring.

7B–8.5 Inspection of the Connecting Rod Bearings

1.Check the connecting rod bearings for wear, poor contact, sign of seizure or loss of tension and replace if defect is found.

2.Install the connecting rod bearing and the bearing cap and tighten the bearing cap bolts to a torque of 58 ft.–lbs. (79 Nm). Then, measure the inside diameter of the bearing with an inside micrometer (Fig. 7B–105).

3.If the oil clearance has increased because of wear in the crankpins, cut to a smaller size and install smaller size connecting rod bearings.

4.To measure the oil clearance, use the following procedure:

(a)Wipe clean the bearings and crankpins to remove oil.

(b)Install a piece of plasti–gauge over the crankpin or bearing in the direction of the axis of the crankshaft.

(c)Install the connecting rod bearing cap and tighten the cap bolts to the correct torque.

B–03013

Fig. 7B–102 Checking Side Play

A–02509

Fig. 7B–103 Checking Weight

A–02507

Fig. 7B–104 Piston Rings

B–02991

Fig. 7B–105 Measuring Rod Bearing

NOTE:Do not move the crankshaft or connecting rods when making this check.

(d)Remove the bearing cap bolts and bearing cap.

(e)Check the width of the plasti–gauge against the scale printed on the instructions (Fig. 7B–106).

NOTE:Never try to file the bearings or install shims to adjust the oil clearance. Make sure the oil clearance is within specifications before installing the bearings. Make sure to get the correct size bearings if the crankshaft is cut under size.

7B–9 CRANKSHAFT

7B–9.1 Inspection of the Crankshaft and Bearings

1.Check the crankshaft bearings and install them using the same method as used for installing and checking the connecting rod bearings.

2.Have the crank journals ground to size indicated in specifications when installing smaller size bearings.

3.Visually check the crank journals, crankpins and oil seal fitting surfaces for damage or wear and check the oil passages for restriction.

4.Use a micrometer to measure the outside diameter of the crank journals and crankpins (Fig. 7B–107). Take measurements at several locations on the crank journals and crankpins to find the amount of wear.

5.If the amount of wear is more than0.002” (0,05 mm), have the crank journals and crankpins cut to size indicated in the specifications and install smaller size bearings.

6.Check the crankshaft for axial alignment and correct if the amount measured is above the amount indicated for servicing (Fig. 7B–108).

7.To check the crankshaft for axial alignment, use the following procedure:

(a)Put the crankshaft on “V” blocks at each end and hold the point of a dial indicator in contact with the center journal.

(b)Slowly turn the crankshaft one full turn and read the dial indicator.

8.Use a feeler gauge to check the crankshaft thrust clearance at the center bearing. If the measured value is over the limit, install an oversize thrust bearing.

NOTE:Install the thrust bearing so that the side with the oil groove is toward the crankshaft thrust face.

7B–10 CAMSHAFT

7B–10.1 Inspection of the Camshaft

1.Check the journals, cam lobes and oil pump drive gear forwear or damage.

2.Use a micrometer to measure the height of the cam lobes.

3.Replace the camshaft if the amount of reduction in the height of the cam lobes is over the limit or if the cam surfaces are found to have bad damage. Small scratches on the cam surfaces can be removed with a polishing stone.

4.Use a micrometer to measure the diameter of the camshaft journals (Fig. 7B–109). Replace the camshaft if the amount of wear is over the value indicating need for servicing.

5.Measure the camshaft end play with a feeler gauge (Fig. 7B–110). Install a new thrust plate if the measured value is overthe value indicating need for servicing.

7B–11

Timing Gear

7B–11.1

Inspection of the Timing Gear

1.Check the timing gears for wear of damage. Replace the timing gears if any defect is found.

2.Measure the clearance between the timing gears, using a feeler gauge or dial indicator. Replace the timing gears if the amount of clearance is over the maximum specifications.

7B–12 MANIFOLD ASSEMBLY

7B–12.1

Inspection of the

Manifold Assembly

1.Check the intake manifold for cracks, corrosion or damage. Correct or replace the manifold as needed.

2.Check the contact surfaces of the intake and exhaust manifolds for distortion. Replace the part or correct by grinding if the amount of distortion is over the limit for servicing.

7B–13 OIL PUMP AND OIL FILTER ASSEMBLY

7B–13.1

Disassembly of the Oil Pump

1.Disconnect the oil pipe (Fig. 7B–111) from the oil pump.

2.Remove the strainer case and pump cover. Then remove the vane (Fig. 7B–112).

3.Remove the pin which holds the pinion.

4.Pull out the pin and remove the rotor.

5.Remove the rotor shaft.

6.Assemble the parts in the reverse of disassembly.

NOTE:When assembling operation is completed, check that the rotor shaft turns smoothly.

7B–13.2 Inspection of the Oil Pump

1.Make a visual check of the vane, rotor and piston gear for wear. Install new parts if the amount of wear is over the specifications.

2.Measure the clearance between the rotor, vane and cover. Make replacement of either the rotor or the vane if the measured amount is over the limit for servicing (Fig. 7B–113).

3.Use a feeler gauge to measure the tip clearance between the rotor and the vane (Fig. 7B–114). Make replacement of the rotor assembly if the measured clearance is over the standard limit.

4.Measure the clearance between the rotor shaft and pump body. Replace the parts if the clearance is over the limit for servicing.

7B–13.3 Oil Filter Assembly (Fig. 7B–115)

1.Remove the oil filter and remove the filter element by turning it counterclockwise.

2.Remove the relief valve and overflow valve.

3.Assemble the parts in the reverse order of disassembly. Install the element by turning it on hand tight only.

7B–13.4

Inspection of the Oil Filter Assembly

1.The relief valve and overflow valve can not be disassembled. Make a visual check of these valves for damage or other defect condition and replace the valve if a defect is found.

2.To check the relief valve opening pressure, use the following procedure: Connect a pressure gauge to the oil gallery at a point closest to the oil filter and check the valve opening pressure with the engine running.

7B–14 WATER PUMP (Fig. 7B–116)

7B–14.1 Disassembly of the Water Pump

1.Remove the rear cover from the body and loosen the bearing setscrew (Fig. 7B–117).

2.Remove the sheave center using a puller (Fig. 7B–118).

3.Remove the shaft and impeller from the body using a press (Fig. 7B–119).

NOTE:The impeller is made of cast iron. Do not use a hammer to remove it.

7B–14.2 Inspection of the Water Pump

1.Check the disassembled parts for wear, cracks or other damage and replace the pump if a defect if found.

2.Check the shaft for being straight.

3.Check the loose bearing unit. Replace the bearing unit if the bearing unit is loose by more than 0.008” (0,2 mm).

7B–14.3 Assembly of the Water Pump

1.Install the thrower and the seal unit on the bearing seat location on the shaft.

NOTE:Install the seal unit so that the side with the spring is toward the impeller.

2.Install the shaft in the water pump body from the sheave side. Use a press and align the screw hole in the water pump body with the screw hole for the outer bearing race (Fig. 7B–120).

3.Use a press to install the impeller on the shaft.

(a)There must be a clearance of about 0.040” (1 mm) between the rear face of the impeller and the inner face of the pump body.

(b)Standard clearance between the outer circumference of the impeller and the pump body is 0.047–0.051” (1,2–1,3 mm) (Fig. 7B–121).

4.Use a press to install the sheave center (Fig. 7B–122).

5.Tighten the setscrew and install the rear cover.

NOTE:When assembly operation is completed, check that the impeller turns smoothly.

7B–15 ASSEMBLY OF THE ENGINE

7B–15.1 Assembly of the Engine

1.Wash and clean the disassembled parts, such as the oil ports, bearings, pistons, cylinders, etc.

2.Put engine oil on the cylinder walls and the bearings and pistons.

3.Install new gaskets at the time of assembly. Use a liquid gasket where it is necessary to prevent oil leakage.

4.Check the oil clearance and other clearances when assembling the parts.

5.Tighten the bolts and nuts to the correct torque.

6.Install the upper half of the crankshaft bearings and thrust bearings on the cylinder block (Fig. 7B–123).

NOTE:Install the thrust bearing so that the side with the oil groove is away from the crankshaft bearings.

7.Put a thin layer of sealant on the connecting areas of the No. 1 and No. 3 bearing caps. Install the bearing caps.

8.Install and tighten the bolts in the bearing caps to the correct torque.

9.When the crankshaft is correctly installed, check the crankshaft for the correct end clearance.

10.Install the gasket on the No. 1 and No. 3 bearing caps. Put sealant on the inner surface of the gasket and install the gasket evenly into the grooves in the bearing cap (Fig. 7B–124). Hold it with the finders for about 5 minutes. Make sure the gasket is 0.002” (0,05 mm) above theend of the bearing cap.

11.Put a thin layer of silicone rubber–base sealant on the outer circumference of the rear oil seal.

12.Fill the clearance between the lips of the oil seal with grease. Install the oil seal.

13.Install the rear plate.

14.Install the flywheel (See Paragraph 7B– . ).

15.Set the piston ring gaps so that their gaps are 180 ° apart from each other.

NOTE:Put engine oil on the cylinder walls and around the pistons and the piston rings.

16.Use a piston ring compressor tool to install the piston and connecting rod assembly. The front mark on top of the piston must be towardthe water pump end of the engine and the connecting rodmust be installed so that the mark is toward the camshaft side.

17.Install and tighten the connecting rod bearing cap bolts. Then check the connecting rod end clearance.

NOTE:Before installing, put cement on the surface of the engine front plate in contact with the cylinder body and injection pump and put the gasket in place.

18.Install the tappets into position from the oil pan side.

19.Install the camshaft. Then install the thrust plate on the cylinder block.

20.Install the oil pump assembly and connect the oil pipe (Fig. 7B–125).

21.Install the oil pan on the crankcase and fasten the crankcase to the cylinder block. Use the following procedure:

(a)Put cement on the upper and lower surfaces of the crankcase, both sides of the oil pan gasket and No. 1 and No.3 bearing cap gaskets for the crankshaft.

(b)Let the cement dry for 10–30 minutes.

(c)Tighten the 4 bolts around the bearing caps. Tighten the remainder of the bolts evenly in sequence. Then finish tightening the 4 bolts.

22.Install the timing gears (Fig. 7B–126).

NOTE:Install the idler gear thrust collar on the idler shaft and install the timing gears so that the “X” and “Y” marks are in correct alignment (Fig. 7B–127).

23.Install the cylinder head.

24.First tighten the cylinder head bolts to 20–35 ft.–lbs. (25–45 Nm) torque in sequence starting with those in the center of the cylinder head (Fig. 7B–128). Then tighten them further to a torque of 45 ft.–lbs. (60 Nm). Then tighten them to the last torque of 60 ft.–lbs. (80 Nm).

25.Connect the oil tubeline for the rocker shaft.

26.Install the push rods.

27.Install the rocker shaft assembly.

28.Adjust the valves for the correct clearance. The clearance is set cold. Use the following procedure to set the valves:

(a)Turn the engine and stop it when the exhaust valve on the No. 2 cylinder is ready to open.

(b)Align the top mark on the crank sheave with the pointer on the timing gear cover (Piston on the No. 1 cylinder is now TDC).

(c)Hold the engine stationary and adjust the intake and exhaust valve clearance on the No. 1 cylinder.

(d)Adjust the intake valve on the No. 2 cylinder.

(e)Turn the crankshaft one complete revolution so that the piston of the No. 2 cylinder is at the bottom of the intake stroke.

(f)Hold the engine and adjust the exhaust valve clearance on the No. 2 cylinder.

29.Install the crankshaft front oil seal on the timing gear cover and fasten the cover with the bolts.

NOTE:Fill the space between the lips of the oil seal with grease before installing the oil seal.

30.Install the injection pump and fasten it with the long bolts forthe timing gear cover (Fig. 7B–129).

NOTE:Align the mark “Z” on the injection pump gear with the mark “Z” on the camshaft gear (See Paragraph 7B–2.6).

31.Install the crankshaft sheave on the crankshaft and tighten the bolt. Bend part of the washer over the head of the bolt.

NOTE:Put a thin layer of oil on the counterbore of the oil seal on the sheave, before installing the sheave.

32.Install the injection nozzle (See Paragraph 7B–2.8) (Fig. 7B–130).

33.Install the rocker arm cover.

34.Install the manifold gasket and muffler/manifold. Install the lifting hook at the rear of the engine.

35.Install the thermostat and thermostat housing. Fasten the thermostat housing and lifting hook with the bolts and tighten.

36.Install the water pump assembly.

37.Install the alternator fastening bracket and the coolant temp–erature switch. Install the alternator and the bolts (See Paragraph 6–7.1, Page 6–6 for the correct belt tension).

38.Install the o–ring on the oil filter and fasten the oil filter assembly to the cylinder block.

39.Install the starter (See Paragraph 6–9.4, Page 6–15).

40.Install the engine in the loader (See Paragraph 7B–3.3).

41.Make sure to add coolant to the radiator and oil to the crankcase before you start the engine.

7B–16 ENGINE FLYWHEEL

7B–16.1

Removing the Flywheel

1.Remove the bolts from the flywheel housing (Fig. 7B–131).

2.Use a pry bar and pry the flywheel housing away from the engine (Fig. 7B–132). Remove the flywheel housing.

3.Remove the adapter bolt (Fig. 7B–133).

4.Use a puller and remove the adapter (Fig. 7B–134).

5.Remove the bolts from the flywheel (Fig. 7B–135).

6.Remove the flywheel from the engine crankshaft.

7B–16.2 Installing the Flywheel

1.Install the flywheel on the crankshaft.

2.Install the bolts in the flywheel and tighten to 58 ft.–lbs. (79 Nm) torque (Fig. 7B–135).

Where applicable specifications conform to SAE standard and are subject to change without notice.

Dimensions are given for loader equipped with standard tires and dirt bucket and may vary with other bucket types. All dimensions are shown in inches. Respective metric dimensions are given in millimeters enclosed by parentheses.

tilt functions controlled by separate foot pedals. Auxiliary function controlled by the right steering lever. Engine Hand lever throttle & key type starter switch.

K582S Fuel Gasoline

8–1.3 Loader Hydraulics

Where applicable specifications conform to SAE standard and are subject to change without notice.

Lift, tilt functions controlled by separate foot pedals. Auxiliary function controlled by the right steering lever. Engine Hand lever throttle & key type starter switch.