IMPORTANT

Damage to the alternator can occur if:

1.Engine is operated with battery cables disconnected.

2.Cables are connected when using fast charger or when welding on the loader (Remove both cables from the battery and disconnect the alternator) (Always disconnect the ground cable first).

3.Extra battery cables are connected wrong.

6–3 BATTERY

6–3.1 Removing the Battery

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

MEL–1069 Battery Terminal Puller

1.Stop the engine. Open the rear door.

2.Disconnect the cables from the battery (Fig. 6–2 & 6–3). Always disconnect the negative cable first to prevent sparks.

3.Remove the nuts and bolts from the holddown clamps (Fig. 6–4 & 6–5) and remove the holddown clamp.

4.Remove the battery and battery bracket from the loader (Fig. 6–6 & 6–7).

6–3.3 Installing the Battery

1.Put the battery bracket in the loader and locate it in the correct position.

2.Install the battery into the battery bracket (Fig. 6–6 & 6–7).

3.Install the battery holddown clamps (Fig. 6–4 & 6–5) and tighten the nuts to 30–50 in.–lbs. (3,4–5,7 Nm) torque.

4.Connect the positive cable first and tighten the clamp.

5.Connect the negative cable and tighten the clamp.

6.Close the rear door.

6–4 WIRE HARNESS FOR THE OPERATOR GUARD

6–4.1 Removing the Wire Harness for the Operator Guard

1.Open the rear door. Disconnect the negative cable from the battery.

2.Disconnect the wiring harness connector behind the seat (Fig. 6–8).

3.Disconnect the connector at the fuel sender wires (Fig. 6–9, Item 1).

4.Remove the harness clip (Fig. 6–9, Item 2).

5.Remove the rear light from the mounting. Disconnect the wires from the rear light (Fig. 6–10).

6.Remove all the harness clips on the operator guard up to the dash panel (Fig. 6–11).

7.Remove the dash panel nuts and bolts (Fig. 6–12).

8.Remove the front lights from the mounting. Disconnect the wires from the front lights (Fig. 6–13).

9.Pull the dash panel down and remove the wires for the front lights from the rubber grommets (Fig. 6–14).

10.Remove the dash panel from the loader and put it on the work bench.

Locate the new wiring harness along side the dash panel. Disconnect a wire from the dash panel, find the wire in the new wiring harness and connect it to the same location.

Also see the WIRING DIAGRAM at the front of the Electrical Section.

6–4.2 Installing the Wire Harness for the Operator Guard

1.After the new wiring harness is installed in the dash panel, make sure that all the terminals are tight.

2.Install the dash panel in the loader.

3.Put the wires for the front lights through the rubber grommets (Fig. 6–14).

4.Put the dash panel in the correct position. Install the bolts and nuts and tighten.

5.Connect the wires to the front lights (Fig. 6–13). Install the front lights in the rubber mounting.

6.Install the harness clips along the side of the operator guard (Fig. 6–11).

7.Put the wires for the rear light through the rubber grommet and connect the wires to the rear light (Fig. 6–10).

8.Connect the wires to the fuel sender (Fig. 6–9, Item 1).

9.Connect the wire harness connectors (Fig. 6–8).

10.Connect the negative cable to the battery.

11.Close the rear door.

6–5 WIRE HARNESS FOR THE ENGINE

When installing a new wiring harness on the engine, locate the new wiring harness by the engine. Disconnect a wire from the engine (Example: oil pressure sender), find the wire in the new wiring harness and connect it to the same location.

Also use the WIRING DIAGRAM at the front of the Electrical Section.

6–6 ALTERNATOR SYSTEM (540)

6–6.1 Checking the A.C. Voltage

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

1.Disconnect the stator wires from the rectifier and connect them to the A.C. voltmeter (Fig. 6–15).

2.Start the engine and run at maximum RPM.

3.The voltage must be 28 or more volts. If the voltage is less than 20 volts @2500 RPM, replace the stator. If the voltage is over 20 volts the stator is good.

6–6.2 Replacement of the Stator

1.Remove the engine blower housing.

2.Hold the flywheel with a piece of wood and remove the nut (Fig. 6–16).

3.Use a puller and remove the flywheel from the engine (Fig. 6–17).

4.Remove the bolts that hold the stator to the engine (Fig. 6–18).

5.Install the new stator and tighten the bolts.

6.Install the flywheel and tighten the nut to 115 ft.–lbs. (156 Nm)torque.

7.Install the blower housing.

6–7 ALTERNATOR SYSTEM (543)

6–7.1 Belt Adjustment for the Alternator

1.Stop the engine. Open the rear door.

2.Loosen the top bolt on the alternator mounting bracket (Fig. 6–19).

3.Loosen the adjusting bolt (Fig. 6–20).

4.Move the alternator to get the correct adjustment on the belt of 1/4” (6,35 mm) movement with 5 lbs. of pressure between the sheaves.

5.Tighten the adjusting bolt (Fig. 6–20).

6.Tighten the top mounting bolt (Fig. 6–19).

7.Close the rear door.

To check the wiring harness use the following procedure:

1.Turn the key switch to the “ON” position.

2.Connect a voltmeter between the ground and the No. 1 terminal of the connector plug (Fig. 6–21) and check the voltage.

3.Connect a voltmeter between the ground and the No. 2 terminal of the connector plug (Fig. 6–21) and check the voltage.

4.Connect the voltmeter between ground and the “Bat” terminal with the wire connected (Fig. 6–21) and check the voltage.

5.If any of the tests in Steps 2, 3 & 4 show zero voltage, the wiring has a defect.

6.Find the defect in the wiring, make repair and check the voltage again.

To check the alternator output, use the following procedure:

1.Stop the engine. Open the rear door.

2.Disconnect the negative cable from the battery.

3.Disconnect the “Bat” connector at the alternator and connect it to one connector of an ammeter. Connect the other side of the ammeter to the “Bat” terminal of the alternator.

4.Connect the negative cable at the battery.

5.Make sure the throttle lever is fully back.

6.Turn the engine, with the starter, for 30 seconds to lower the charge in the battery.

7.Push the throttle lever forward and start the engine and run at full RPM.

8.The ammeter reading must be within 10% of the rated amperage (which is 37 amps at 2750 RPM).

9.If the reading is correct, the alternator is good. If the reading is more or less than 10% of rated amperage, check the regulator.

To check the regulator, use the following procedure:

1.Use Steps 2 thru 7 for alternator output.

Test Hole

2.Put a small screwdriver in the test hole (Fig. 6–22).

3.If the ammeter is within 10% of rated amperage (which is 37 amps at 2750 RPM) the regulator is good. If the reading is not within 10% of rated amperage, check the diode trio, rectifier, stator or rotor (See Paragraph 6–7.4).

6–7.3 Removing the Alternator

1.Stop the engine. Open the rear door.

2.Disconnect the negative cable from the battery.

3.Remove the engine blower housing from the engine(See Paragraph 7B–3.1, Page 7B–9).

4.Remove the adjustment bolt (Fig. 6–23).

5.Remove the belt (Fig. 6–24).

6.Remove the top bolt from the mounting bracket (Fig. 6–25).

7.Remove the alternator from the mounting bracket.

8.Disconnect the connector from the alternator (Fig. 6–26, Item 1).

9.Remove the wire from the alternator (Fig. 6–26, Item 2).

6–7.4 Repairing the Alternator

1.Put a mark across the alternator case for correct assembly.

2.Remove the sheave from the alternator shaft.

3.Remove the four (4) bolts that hold the case halves together.

4.Use a screwdriver to pry the case halves apart.

5.Remove the rotor from the housing.

6.Remove the three (3) nuts that hold the stator wires to the housing. Remove the stator.

7.Disconnect the diode trio.

8.Connect the ohmmeter between one slip ring and the shaft. There must be maximum resistance (Fig. 6–27).

9.Connect the ohmmeter between both slip rings. There must be 2.3 to 3 ohms of resistance. If there is not, there is a defect in the rotor (Fig. 6–27).

10.Connect a test light between the center wire and one of the outside wires on the stator (Fig. 6–28). If the light does not come “ON” there is a defect.

11.Connect the test light between the center wire and the other side outside wire (Fig. 6–28). If the light does not come “ON” there is a defect.

12.Connect the test light between one of the wires and the stator frame (Fig. 6–28). If the light comes “ON” there is a defect.

Important

Do not use high voltage to check diode trio or rectifier.

13.Connect a D.C. test light between the single connection and on one of the three (3) connections (Fig. 6–29). Connect the tester in the opposite direction. The light must come “ON” in one direction, but not in the other direction.

14.Do Step 13 for the otherdiodes.

15.Connect the test light between the center connections and each outside connection. If the light comes “ON” on either side, there is a defect.

16.Remove the rectifier from the alternator.

17.Connect a test light between one connection and the insulated heat sink (Fig. 6–30). Connect the test light in the other direction. The light must come “ON” in one direction but not in the other direction.

18.Connect the test light between the same connection and ground heat sink (Fig. 6–30). Connect the tester in the other direction. The light must come “ON” in one direction, but not in the other direction.

19.Do Steps 17 & 18 on both the other connections. If any of the tests are bad, make replacement of the rectifier.

20.Install the rectifier.

Insulated Washers

21.If the regulator is removed, make sure when installing it to replace the two (2) insulated washers and spacers (Fig. 6–31).

22.Install the diode trio.

23.Install the stator and connect the wires.

24.Install the new brushes and put a piece of straight wire through the housing to hold the brushes in the up position.

25.Install the rotor and remove the wire.

26.Put the case halves together and install the bolts and tighten.

27.Install the sheave and tighten the nut to 50 ft.–lbs. (68 Nm) torque.

6–7.5 Installing the Alternator

1.Connect the wire at the alternator (Fig. 6–33, Item 1).

2.Connect the wire connector to the alternator (Fig. 6–33, Item 2).

3.Put the alternator in the mounting bracket and installthe top bolt (Fig. 6–34).

4.Install the belt (Fig. 6–35).

5.Install the adjusting bolt. Do not tighten (Fig. 6–36).

6.Adjust the alternator belt for the correct tension.

7.Install the engine blower housing (See Paragraph 7B–3.4, Page 7B–13).

8.Connect the negative cable to the battery.

6–8 STARTER (540)

6–8.1 Checking the Starter

1.Make sure the ignition is in the “OFF” position. Make sure the battery has a full charge and the cable connections are clean and tight.

2.Connect the jumper wire between the solenoid connection (Fig. 6–37, Item 1) and the “BAT” connection (Fig. 6–37, Item 2). If the starter turns but the engine does not, the defect is in the starter drive. If the starter does notturn, go to Step 3.

3.Connect a jumper wire between the “M” connection (Fig. 6–37, Item 3) and the “BAT” connection (Fig. 6–37, Item 2). If the starter turns the defect is in the solenoid.

6–8.2 Removing the Starter

1.Stop the engine. Open the rear door.

2.Disconnect the negative cable from the battery.

3.Remove the wire from the starter (Fig. 6–38).

4.Remove the starter bolts (Fig. 6–39).

5.Remove the starter from the engine.

6–8.3 Repairing the Starter

1.Pull the rubber cap off the end of the starter shaft.

2.Use two (2) wrenches to remove the nut on theend of the starter shaft (Fig. 6–40).

3.Remove the starter drive parts (Fig. 6–41).

4.Put a mark on the side of the starter housing and end plates for easier assembly.

5.Check the condition of the brushes. If the brushes areless than 5/16” (8 mm) in length, install new brushes (Fig. 6–42).

6.Check the commutator (Fig. 6–43) and check the armature in the growler.

7.Check all the parts of the starter for damage. Add lubricant to the bushings and assemble the starter parts.

NOTE:DO NOT put lubricant on the starter drive splines.

6–9 STARTER (543)

6–9.1 Checking the Starter

1.Make sure the ignition is in the “OFF” position. Make sure the battery has a full charge and the cables are clean and tight.

2.Connect a jumper wire between the “S” connection and “BAT” connection (Fig. 6–44). If the starter turns, but the engine does not turn, the defect is in the starter drive. If starter does not turn go to Step 3.

3.Connect a jumper wire between the “M” connection and the “BAT” connection (Fig. 6–45). If the starter turns, there is a defect in the solenoid.

6–9.2 Removing the Starter

1.Stop the engine. Open the rear door.

2.Disconnect the negative cable from the battery.

3.Remove all the wires from the starter solenoid (Fig. 6–46).

4.Remove the starter mounting bolts (Fig. 6–47).

5.Remove the starter from the engine.

6–9.3 Repairing the Starter

1.Disconnect the connector link between the solenoid and starter.

2.Remove the solenoid bolts (Fig. 6–48, Item 1) that fasten the solenoid to the drive end of the starter.

3.Remove the solenoid (Fig. 6–48, Item 2).

4.Remove the bolt (Fig. 6–48, Item 3) and remove the shift fork (Item 4).

5.Remove the bolts (Fig. 6–48, Item 5) from the end cap (Item 6).

6.Remove the shim washers (Fig. 6–48, Item 7) from the armature (Item 8) shaft at the commutator end.

7.Remove the armature, complete with the internal thrust washer (Fig. 6–48, Item 9) and the drive assembly (Item 10) through the drive end of the starter frame.

8.Remove the thrust washer (Fig. 6–48, Item 11) from the commutator end of the armature shaft.

9.Remove the drive shaft ring (Fig. 6–48, Item 12), thrust collar (Item 13) and slide the drive assembly off the armature shaft.

10.Use a brush and air pressure to clean the drive, field coils, armature, front plate and rear housing.

NOTE:DO NOT use solvent to clean the drive assembly because the solvent will remove the lubricant and the drive will slip.

11.Inspect the armature for broken or burned insulation and loose connections at the commutator.

12.Check the armature for opens and grounded circuits (Fig. 6–49 & 6–50).

13.Check the armature shaft and bearings for damage and wear. If the commutator is rough, cut it in a lathe to make is smooth.

14.Check the brush holders for broken springs and for broken insulation.

15.Check the spring tension for the brushes.

16.Inspect the field coils for burns or broken insulation and electrical continuity (Fig. 6–51). Check the field brush connections and wire insulation.

17.Check the starter drive gear for tooth wear. The starter drive gear must engage more than 1/2 the depth of the ring gear teeth on the flywheel.

18.Put a small amount of grease on the shaft of the armature (Fig. 6–48, Item 8). Install the drive assembly (Item 10) and install the thrust collar (Item 13) and the stop ring (Item 12).

19.Install the thrust washer (Fig. 6–48, Item 11) on the shaft of the armature.

20.Install the armature into the starter housing.

21.Install the brushes in the end plate (Fig. 6–48, Item 14) and install the end plate on the starter housing.

22.Put a small amount of grease in the gushing (Fig. 6–48, Item 15) and install the drive housing end.

23.Install the bolts (Fig. 6–48, Item 5) and tighten. Check the end play of the starter. If there is too much end play or not enough, add or remove shims (Item 17) at the drive end of the armature.

24.Install the shift fork (Fig. 6–48, Item 4) andthe pivot bolts (Item 3) and tighten.

25.Install the solenoid (Fig. 6–48, Item 2). Install the bolts (Item 1) and tighten.

26.Connect the link between the solenoid and the starter.

Fig. 6–49 Checking Armature

A–01995

A–01994

Fig. 6–50 Checking Armature

B–02122

Fig. 6–51 Checking Field Coils

6–9.4 Installing the Starter

1.Install the starter into the flywheel housing.

2.Install the starter mounting bolts (Fig. 6–52) and tighten to 25–28 ft.–lbs. (34–38 Nm) torque.

3.Connect the wires to the solenoid (Fig. 6–53).

4.Connect the negative cable at the battery.

5.Close the rear door.

ENGINE SERVICE (KOHLER–540)

ENGINE SERVICE (ISUZU–543)

ParagraphPage

DO NOT service the Bobcat loader without instructions or taking the necessary safety precautions. Before working on the loader, see the warnings and instructions at the beginning of this Service Manual. After making the repair or adjustment, always check the function of the loader. Failure to obey warnings may cause injury or death.

ENGINE SERVICE (540)

ParagraphPage NumberNumber

CARBURETOR & FUEL SHUT–OFF SOLENOID 7A–37A–6 . . . . . . . . . . . . . .

CHECKS & ADJUSTMENTS 7A–27A–3 . . . . . . . . . . .

CYLINDER HEAD 7A–107A–15

ENGINE & HEAT SHIELD 7A–57A–8

FLYWHEEL7A–127A–15

GOVERNOR7A–47A–7

INTAKE & EXHAUST MANIFOLD 7A–117A–15

OIL PUMP & RELIEF VALVE7A–87A–12 . . . . . . . . . .

PISTONS, RODS AND CRANKSHAFT 7A–97A–13 . .

RECONDITIONING THE VALVES 7A–67A–10 . . . . . .

TIMING COVER, TIMING GEARS & CAMSHAFT7A–77A–11

TROUBLESHOOTING7A–17A–1

DO NOT service the Bobcat loader without instructions or taking the necessary safety precautions. Before working on the loader, see the warnings and instructions at the beginning of this Service Manual. After making the repair or adjustment, always check the function of the loader. Failure to obey warnings may cause injury or death.