Caterpillar 3508B Engine

1. Remove the drive belt guard.
2. Loosen mounting bolt (1), adjusting nuts (2) and mounting bolt (3).
3. Turn adjusting nuts (2) to increase or decrease drive belt tension.
4. Tighten adjusting nuts (2), mounting bolt (3), and mounting bolt (1).
5. Reinstall the drive belt guard.
6. If new belts installed, recheck tension after 30 minutes at rated rpm.

⚠ Slippage of loose belts can reduce efficiency of driven components

⚠ Too tight belts place unnecessary stress on components

1. Remove the drive belt guard.
2. Loosen mounting bolt, adjusting nuts and mounting bolt.
3. Turn adjusting nuts to increase or decrease drive belt tension.
4. Tighten adjusting nuts and both mounting bolts to proper torque.
5. Reinstall the drive belt guard.
6. If new drive belts are installed, recheck tension after 30 minutes.

⚠ Check the wiring for the air shutoff switches, and for the solenoids

1. Do not start the engine; ensure engine control is OFF.
2. Verify both air shutoff gates latched OPEN and switches connected.
3. Turn panel power ON; gates should remain open.
4. Activate EMERGENCY STOP; both gates should close.
5. Reset; latch only right gate; power ON; right gate should close.
6. Latch only left gate; power ON; left gate should close.
7. Operate engine normally; ensure gates remain latched.

⚠ High voltage can cause electrocution. Discharge instrument leads and generator windings.

Tools: 300-8648 Insulation Testing Gp

1. Take the generator out of service.
2. Visually inspect generator for moisture. If moisture exists, dry the unit first.
3. Inspect installation. Determine equipment that will be tested.
4. Discharge capacitance of the windings. Disconnect 'T0' from ground.
5. Disconnect sensing lead wires for regulator and PT leads of load share module.
6. Connect insulation tester Black lead to ground; RED lead to 'T0'.
7. Set voltage to rated voltage. Apply voltage; observe readings at 30 and 60 seconds.
8. Record 60 second reading (correct for temperature), temperature, and humidity.

⚠ Do not use a high concentration of caustic cleaner

⚠ Do not use high pressure when the fins are cleaned

1. Remove the core.
2. Turn the aftercooler core on one side; remove accessible debris.
3. Back flush the core with cleaner.
4. Remove the drain plug; steam clean the core; flush the fins.
5. Wash the core with hot, soapy water.
6. Flush thoroughly with clean, fresh water until clear.
7. Dry the core with compressed air opposite to normal flow direction.
8. Inspect O-rings/seals; pressure test for leaks; install the core.

⚠ Batteries give off combustible gases which can explode; ensure proper ventilation.

⚠ Always recycle a battery; never discard a battery.

1. Turn key start switch OFF. Remove key and all electrical loads.
2. Turn OFF battery charger. Disconnect the charger.
3. Disconnect NEGATIVE '-' cable from NEGATIVE battery terminal.
4. Disconnect POSITIVE '+' cable from POSITIVE battery terminal.
5. Remove the used battery. Install the new battery.
6. Connect starting motor cable to POSITIVE '+' battery terminal.
7. Connect ground plane cable to NEGATIVE '-' battery terminal.

⚠ Hot coolant can cause serious burns

⚠ Use only cooling system cleaners approved for Caterpillar engines

Tools: 9S-8140 Pressurizing Pump

1. Stop engine, allow to cool, relieve pressure, remove filler cap.
2. Open drain valves or remove drain plugs; drain coolant.
3. Flush cooling system with clean water.
4. Close drains; fill with water and Fast Acting Cooling System Cleaner.
5. Operate engine 30 minutes with coolant temperature at least 82 C.
6. Stop, cool, drain; flush with clean water until clear.
7. Fill with coolant/antifreeze; do not install filler cap.
8. Run engine to purge air; check level; install cap.

⚠ Use only clean water to flush the cooling system when ELC is drained

Tools: 9S-8140 Pressurizing Pump

1. Stop engine, allow to cool, relieve pressure, remove filler cap.
2. Open drain valves or remove drain plugs; drain coolant.
3. Flush the cooling system with clean water.
4. Fill with clean water; run until 49 to 66 C; drain.
5. Repeat flush steps until water drains clean.
6. Fill with Extended Life Coolant; do not install filler cap.
7. Run engine to purge air; check coolant level.
8. Inspect filler cap gaskets; install cap; inspect for leaks.

⚠ Never run the engine without an air cleaner element installed

⚠ Never service the air cleaner element with the engine running

1. Remove the cover and the primary air cleaner element.
2. Discard the secondary element for every three cleanings of the primary element.
3. Cover the turbocharger air inlet with tape to keep dirt out.
4. Clean inside of air cleaner cover and body with a clean dry cloth.
5. Remove tape; install secondary and primary air cleaner elements.
6. Install the air cleaner cover.
7. Reset the air cleaner service indicator.

⚠ In dusty applications, more frequent cleaning is required.

1. Remove wing nut (1) and cover (2).
2. Check for accumulation of dirt and debris in body (3). Clean the body, if necessary.
3. After cleaning the precleaner, install cover (2) and wing nut (1).

⚠ Do not attempt to disassemble the breathers.

1. Loosen clamp (1). Slide the clamp down on tube (2).
2. Loosen clamps (3). Remove both breathers as a unit.
3. Remove O-ring seals (4) from valve covers. Inspect; obtain new seals if necessary.
4. Remove two clamps (6). Remove both breathers (5) from hose tee (7). Inspect tee for cracks.
5. Turn breathers upside-down. Clean breather elements with clean, nonflammable solvent.
6. Allow breather elements to dry before installation. Do not disassemble breathers.
7. Install breathers into tee; tighten clamps to the torque in Service Manual, Specifications.
8. Coat O-ring seals with clean engine oil; install and tighten clamps.

⚠ Hot oil and components can cause personal injury.

⚠ Parts and covers are under spring pressure.

Tools: Utility knife (inspect used filter)

1. After operating at normal temperature, STOP the engine. Drain the warm oil.
2. Open oil drain; after oil has drained, close the oil drain.
3. Gradually loosen but do not remove bolts (4); pry cover (5) loose to relieve spring pressure.
4. Remove cover and O-ring seal. Clean cover, seal, and inside of oil filter housing.
5. Install new oil filter elements. Install new O-ring seal if damaged.
6. Install cover (5); ensure springs are seated properly.
7. Fill crankcase through oil filler tube only. Clean and install oil filler cap.
8. Close fuel supply; crank until oil pressure gauge indicates 70 kPa (10 psi).