Cummins/Onan MDKAD Generator Set

⚠ Accidental starting can cause severe personal injury or death. Disconnect the negative battery cable(s).

1. Disconnect negative battery cable(s) and remove belt guard or sound shield door.
2. Loosen the alternator pivot bolt first and then the adjusting bracket bolt on top.
3. Pivot the alternator outwards to tighten belt; hold tension by tightening the adjusting bracket bolt.
4. Apply 20 pounds (10 kg) to the middle of the pulley span; deflection should be 0.4 inch (10 mm). Tighten alternator bolts.
5. Secure belt guard or sound shield door and reconnect battery cables (negative last).

1. Conduct sea trials to establish the load water line if a wet exhaust system is employed.
2. Install a siphon break securely, upright, at least 12 inches above the load water line if the exhaust outlet is less than 6 inches above it.
3. Verify by sea trials that the sea water inlet causes no excessive restriction or ram pressure.
4. Verify by sea trials that there is no backflow through the sea water exit port.
5. Securely and adequately mount the genset.
6. Provide adequate clearance for all maintenance specified in the Operator's Manual.
7. Mount the coolant recovery tank properly and keep it accessible for inspection and filling.
8. Fill the engine with the proper levels of oil and coolant.
9. Prime the sea water pump and open the sea cock.
10. Confirm the entire exhaust system is accessible for inspection and replacement.
11. For dry exhaust, use approved methods and materials to protect combustible construction and operators from hot mufflers and piping.
12. Use approved flexible fuel lines at the engine and confirm fuel tanks and piping comply with regulations.
13. Confirm generator room ventilation meets regulations and the genset is bonded to the vessel grounding bus.
14. Confirm the transfer switch (if required) and AC wiring methods, materials and bonding for grounding meet regulations.
15. Install a properly sized, serviced, charged battery; verify the remote control panel, acceptable exhaust back pressure, and leak-free fuel, coolant and sea water systems.

⚠ Hot coolant is under pressure and can cause severe burns when loosening the pressure cap.

⚠ Filling a hot engine with cold water can cause cracks in the manifold, head and block.

1. Let engine cool, disconnect negative battery cable(s), remove pressure cap and open block and heat exchanger drain cocks.
2. Collect used coolant in containers for proper disposal.
3. Use radiator cleaning chemicals to clean and flush the cooling system before new coolant is added.
4. Close all drain cocks, secure hose clamps and fill system through fill opening to bottom of fill neck.
5. Start and run the engine for a minute to dislodge air pockets and shut it down.
6. Add as much coolant as necessary and secure the pressure cap.

⚠ Crankcase pressure can blow out hot oil and cause severe burns. Stop the engine before checking oil level or opening fill cap.

⚠ Used engine oil can cause cancer or reproductive toxicity.

Tools: Two wrenches to keep from twisting the drain hose

1. Run the engine until thoroughly warm and then stop it.
2. Unscrew the plug on the end of the drain hose and drain oil into a suitable container; reinstall plug.
3. Place a container under the oil filter and spin off the oil filter.
4. Clean filter mounting surface, apply oil to new filter gasket, spin on until gasket touches pad, tighten an additional 3/4 turn.
5. Refill with the proper amount of oil and start the engine; check for leakage around the filter gasket.
6. Shut off the genset, recheck the oil level and add oil as necessary.

1. Remove the drain plug and collect the water and sediment (about 1/2 cup [120 ml]) in a suitable container.
2. Dispose of properly.
3. Reinstall the plug securely.

⚠ High pressure oil spray from an injector line fitting can penetrate the skin. Wear safety glasses and keep hands away from spray.

⚠ Preheating for more than 15 seconds at a time reduces glow plug life.

Tools: Two flare-nut wrenches

1. Hold control switch in Stop position to run fuel lift pump; do not prime more than 15 seconds at a time.
2. On MDKAD or MDKAE, open the bleed valve (counterclockwise) to bleed air and fuel back to the supply tank.
3. Hold control switch in Stop position as long as necessary to remove all air from the fuel supply system.
4. High-pressure side: loosen the high pressure fittings at the nozzles using two flare-nut wrenches.
5. Crank the genset until fuel appears at loosened fittings, then snug up each fitting.
6. Shut down the engine and torque the fittings to 19 - 25 lb-ft (25 - 34 N-m).

⚠ Hot coolant is under pressure and can cause severe burns when loosening the pressure cap.

1. Let engine cool, loosen pressure cap and disconnect negative battery cable(s).
2. Remove the two thermostat housing bolts and pull off the housing, thermostat and gasket.
3. Clean off the gasket area and reassemble with the new thermostat and gasket.
4. Apply Three Bond 1215 liquid sealant or equivalent to the top side of the gasket.

⚠ Fuel leaks can lead to fire. Repair leaks immediately.

1. Drain the filter and spin off the element.
2. Clean the contact surface of the base.
3. Lubricate the new element and its gasket, and fill the element with clean diesel fuel.
4. Spin the new element onto the base and hand tighten.
5. Start and run the genset and check for fuel leakage.

⚠ Do not lubricate with petroleum products like grease and oil which attack impeller materials.

⚠ The pump gets hot quickly if there is no flow and can burn your fingers.

Tools: Two pairs of pliers

1. Disconnect the negative battery cable(s).
2. Close the sea cock and remove the impeller cover and O-ring.
3. Using two pairs of pliers, grip vanes on opposite sides and pull out the old impeller.
4. Install the new impeller, twisting clockwise; push in all the way until keyway lines up with shaft key.
5. Wet the inside of the pump and impeller with water, soap solution or silicone lubricant and secure O-ring and cover.
6. If strainer is above water line, fill strainer element cover with water and reinstall cover.
7. Open sea cock, reconnect battery cables and start genset; shut down within 30 seconds if there is no water flow.

⚠ Crankcase pressure can blow out hot oil and cause severe burns.

⚠ Hot coolant is under pressure and can cause severe burns.

⚠ Arcing at battery terminals can ignite battery gas causing severe personal injury.

1. Run the genset until it has thoroughly warmed up and shut it down.
2. Change the oil and oil filter while still warm; attach a tag to the dipstick indicating oil viscosity grade.
3. Disconnect the battery cables (negative first) and store the battery(ies) per manufacturer's recommendations.
4. Check coolant level and add coolant as necessary; test and change coolant mixture if freezing temperatures possible.
5. If freezing temperatures are expected, drain the heat exchanger of sea water at the drain plug; replace plug when drained.
6. Clean the genset and lightly oil parts that can rust.

1. Check the tag on the dipstick and change the oil if viscosity is not suitable for present and anticipated ambient temperatures.
2. Reconnect the battery(ies) (negative cables last) and service as necessary.
3. Prime the fuel system.
4. Replace the sea water pump impeller if installed more than a year ago; else wet pump internal surfaces with water.
5. Perform PRE-START CHECKS and start and run the genset according to STARTING.

⚠ Preheat times longer than 15 seconds can damage the glow plugs.

⚠ Excessive cranking can overheat and damage the starter.

1. Disconnect all loads from the genset.
2. Hold the control switch in the PREHEAT position for 5 to 15 seconds.
3. Immediately after PREHEAT push the control switch to START and hold until engine starts.
4. Connect electrical loads after the genset has warmed up for a few minutes.
5. Check for fuel, exhaust, oil and coolant leaks and complete General Inspection.