Cummins/Onan QSK23 Engine

⚠ The maximum engine speed should only be altered by a Cummins technician.

1. Start the engine.
2. Observe that the engine accelerates to the currently adjusted speed setpoint.
3. Locate the threaded linkage rod on the fuel pump side of the engine.
4. Loosen the locking nuts against the stops on the threaded rod.
5. To increase speed, turn the bolt on the right side of the throttle bracket clockwise.
6. To decrease speed, turn the bolt counter-clockwise.
7. When the rated speed is correct, tighten the locking nut against the stop.
8. Adjust the left-side threaded bolt for maximum speed if needed.
9. Stop the engine and repeat until the desired speed is attained.

⚠ Use Teflon tape or pipe sealant when installing test setup.

Tools: pressure gauge 689 kPa (100 psi)

1. Install an adapter at the cooling water outlet of the heat exchanger.
2. Install a pressure test setup with 689 kPa (100 psi) gauge at the cooling water inlet.
3. Apply air pressure at 276 kPa (40 psi).
4. Isolate pressure source and monitor gauge for five minutes.
5. Release pressure and remove test equipment.

1. From the User Interface screen press the MENU soft key.
2. Press the OVERSPEED TEST soft key from the Settings Menu.
3. Press the RUN soft button.
4. When the dialog box appears, proceed with the test and select Yes.
5. When the timer expires, ENGINE OVERSPEED flashing in red appears at the top of the FPDP screen.
6. The engine will enter MANUAL mode until reset.
7. Press the RESET/STOP switch on the FPDP to reset the fire pump drive engine.

Tools: Digital multimeter

1. From the User Interface screen press the MENU soft key.
2. Press the ENGINE SETUP soft key from the Settings menu.
3. Enter password 806 in the Engine Setup Login screen.
4. Press the TERMINAL BLOCKS soft key from the Engine Setup menu.
5. Press the soft key corresponding to the terminal block requiring verification.
6. Press the RETURN soft key to exit the Terminal Block Test menu.

⚠ Battery electrolyte (sulfuric acid) is highly caustic.

⚠ Batteries can emit explosive gases during charging.

⚠ Remove the negative (-) battery cable first and attach it last.

Tools: Neoprene gloves, Safety goggles or full face shield

1. Install the battery cable kit or equivalent customer-supplied wiring.
2. Install battery sets in a well-ventilated or otherwise protected location.
3. Provide adequate room for servicing or replacing the batteries.
4. Locate the batteries near the engine or increase conductor size as required.
5. Check the battery cables and connections.
6. Coat the terminals with petroleum jelly to prevent corrosion.

⚠ A fully populated USB cable, Part Number 4918419, or DB9F-DB9M serial cable, Part Number 4918418, must be used.

1. Connect the DB9F-DB9M serial cable, Part Number 4918418, or USB cable, Part Number 4918419, to the computer.
2. Connect the other end of that cable to the INLINE™5 datalink adapter, Part Number 3165033.
3. Supply +8 VDC to +50 VDC at 250mA through the OEM connector or a separate power source.
4. Connect the appropriate datalink cable to the INLINE™5 datalink adapter, Part Number 3165033.
5. Connect the other end of the datalink cable to the vehicle cab or engine compartment datalink connector.
6. Launch the electronic service tool application software.

⚠ The cooling water supply must be immediately available when the engine is started.

⚠ Do not operate without a pressure cap.

Tools: Appropriate-sized container

1. Provide a cooling water discharge line at the heat exchanger outlet and a supply line to the cooling water inlet.
2. Check the pressure regulator setting on the cooling loop with water flowing through the heat exchanger.
3. Adjust the cooling water based on water flow rather than water pressure.
4. Measure the water flow using a container and elapsed time.
5. Adjust both pressure regulators to provide flow at or above specifications.

⚠ Do not use the engine lifting points for assembly!

Tools: Lifting device, Grease gun

1. Ensure the engine and pump are correctly aligned.
2. Verify engine position centered on frame side to side within +/- .76 mm (.03 in).
3. Align engine center line to pump center line within +/- .76 mm (.03 in).
4. Ensure pump center line to engine crankshaft center line (vertical) is 2 degrees +/- 1 degree.
5. Ensure drive shaft mounting flanges are parallel.
6. Lubricate the grease fittings on the drive shaft universal joint.
7. Check engine is installed per pump manufacturer's specifications.

⚠ Do not use copper or galvanized pipe for the fuel return or supply lines.

⚠ Do not mix gasoline, alcohol, gasohol, ethanol, or methanol with diesel fuel.

Tools: Container for contaminated fuel

1. Install an elevated no. 2 diesel fuel tank or equivalent compatible with ASTM no. 2 diesel specifications.
2. Size the fuel tank for the maximum expected full-load operation period.
3. Install a fuel return line routed to the bottom of the fuel tank.
4. Install a fuel supply line to the fire pump drive engine.
5. Open the fuel filter/water separator drain and drain until no water is present.

⚠ Disconnect batteries (negative cable first) before service.

Tools: Cummins belt tension gauge 3822524

1. Place engine in MANUAL and disconnect both batteries (negative first).
2. Remove belt guard capscrews and belt guard.
3. Visually inspect belt for frayed, worn, missing pieces or intersecting cracks.
4. Check belt tension using Cummins belt tension gauge 3822524 at center span.
5. Reinstall battery cables (negative last).

⚠ Do not remove the pressure/fill cap from a hot engine. Wait until coolant temperature is below 50 C (122 F).

Tools: Refractometer

1. Inspect the engine coolant hoses and hose clamps for proper installation and water tightness.
2. Ensure the engine coolant heater maintains coolant temperature of 49 C (120 F) or above.
3. Ensure coolant is present in the coolant heater before plugging into a dedicated circuit.
4. Inspect the heat exchanger weekly for external damage and contamination.
5. Add coolant if necessary: with sight gauge, keep level visible at center; without, fill to bottom of fill neck.
6. Re-install the pressure/fill cap.

⚠ Do not remove pressure cap from hot engine; wait until below 50 C (120 F).

⚠ Coolant is toxic - dispose per regulations.

Tools: filter wrench, container (57 L)

1. Disconnect both batteries (negative first).
2. Remove coolant expansion tank pressure/fill cap.
3. Disconnect engine coolant heater power supply.
4. Place container (min 57 L) under coolant drain valve.
5. Open the drain petcock and drain coolant; drain engine heater.
6. Flush with clean fresh water or heat exchanger cleaner.
7. Install new coolant filter if needed.
8. Fill with 50/50 antifreeze mixture and vent air.
9. Operate engine to 82 C (180 F) and check for leaks.