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Kubota L2800, L3010, L3130 - Engine Checking and Service

Kubota L3010, L3130 tractors fitted with D1503 diesel engine. D1403 engine used in L2800 model.

Kubota L2800, L3010, L3130 - Engine Troubleshooting

Engine will not start

Check for an empty fuel tank, incorrect fuel or water in the fuel. Bleed the fuel system to be sure that fuel is routed to the fuel injection pump and to locate any restrictions, such as the fuel filter, or defective components, such as the fuel transfer pump. Check for proper operation and adjustment of the speed control mechanism, including the stop lever. Check the fuel injection timing.

Engine speed decreases unexpectedly

Check for water in the fuel. Check for a clogged fuel filter element. Bleed the fuel system to remove air in the fuel. Check for clogged or defective fuel injection pump or fuel injector.

Engine will not run under full load

Check for a clogged fuel filter element. Check for a defective fuel transfer pump. Check for a clogged or defective fuel injection pump. Check the speed control mechanism.

Engine misfires

Check for water in the fuel. Check for a clogged fuel filter element. Check for a clogged or defective fuel injection pump or fuel injector.

Kubota D1503 engine Overheating

Loose pump drive belt - A loose drive belt prevents the circulating pump from operating at the proper speed. Loose hose or pipe connections - Air may be drawn into the suction side of the system. Worn or defective water pump - A worn or defective pump may not provide sufficient cooling water. Dirty cooling system - Debris in the cooling system prevents adequate heat transfer to the cooling water. Defective or incorrect thermostat - A defective thermostat may stay closed or not open sufficiently to allow hot water to leave the engine. An incorrect thermostat may open at a temperature higher than specified, thereby raising the temperature of the cooling water in the engine. Conversely, a thermostat that stays open and doesn’t close or opens at a low temperature will cause the engine to run at less than optimum temperature.

Engine Stops Suddenly

This can be caused by engine seizure, a governor malfunction or a problem in the fuel system. Attempt to start the engine to determine if the engine rotates freely. Check governor adjustment or to repair the governor.

Low Oil Pressure

Low engine oil pressure may be caused by leakage in the oil circuit, excessive bearing clearance, a clogged oil filter, a loose oil regulator valve or incorrect oil viscosity. Low oil pressure may also be caused by engine overheating or oil dilution by fuel in the crankcase. Verify low oil pressure by performing the oil pressure test.

Blue Smoke

Blue exhaust smoke indicates that oil is burning during the combustion process. Look for a condition that allows oil to enter the combustion chamber, such as a broken piston, broken or stuck piston rings, a damaged cylinder wall, worn valves or guides, a defective crankcase vent, or an overfilled oil sump.

White Smoke

Unburned fuel causes white exhaust smoke. The unburned fuel may be due to retarded fuel injection timing or insufficient compression pressure. Low compression pressure may be caused by a damaged cylinder gasket, broken piston rings, leaking valves or incorrectly adjusted valves. Raw, unburned fuel may be due to incorrect fuel (low cetane rating) or a defective injector.

Black Smoke

Black exhaust smoke results from excess fuel (rich) that forms soot when burned. Either excess fuel or insufficient air can cause black smoke. Some possible causes are a defective fuel injection pump, poor injector spray pattern, low injection opening pressure, clogged air intake, restricted exhaust system or low compression pressure.

Kubota D1503 engine knocks

Check the fuel injection pump timing. Check for a defective fuel injection pump.

Clicking or Tapping Noises

Clicking or tapping noises usually come from the valve train and indicate excessive valve clearance. A sticking valve may also sound like a valve with excessive clearance. In addition, excessive wear in valve train components can cause similar engine noises.

Knocking Noises

A heavy, dull knocking is usually caused by a worn main bearing. The noise is loudest when the engine is working hard, such as accelerating at low speed. It is possible to isolate the trouble to a single bearing by disabling the fuel injectors on 3-cylinder engines one at a time. By disabling the fuel injector nearest the bearing, the knock will be reduced or disappear. Worn connecting rod bearings may also produced a knock, but the sound is usually more metallic. As with a main bearing, the noise is worse during acceleration. It may increase in transition from acceleration to coasting. Disabling the fuel injectors will help isolate this knock as well. A double knock or clicking usually indicates a worn piston pin. Disabling fuel injectors will isolate this to a particular piston; however, the noise will increase when the affected piston is reached. A loose flywheel and excessive crankshaft end play also produce knocking noises. While similar to main bearing noises, they are usually intermittent, not constant, and they do not change when fuel injectors are disabled. If caused by a loose flywheel or coupling, the noise is generally heard at idle or during rapid deceleration. Recheck flywheel/coupler bolt torque whenever accessible. Some mechanics confuse piston pin noise with piston slap (excessive piston clearance). The double knock will distinguish piston pin noise. Piston slap will always be louder when the engine is cold.

Kubota L2800, L3010, L3130 - Engine Checking

Air bleeding the fuel system

Air bleeding of the fuel system is required if: After the fuel filter and pipes have been detached and refitted; after the fuel tank has become empty; or before Kubota D1503/D1403 engine is to be used after a long storage. Fill the fuel tank to the fullest extent. Open the fuel filter lever. Open the air vent cock on top of the fuel injection pump. Turn the engine, continue it for about 10 seconds, then stop it, or move the fuel feed pump lever by hand (optional). Close the air vent cock on top of the fuel injection pump. Always keep the air vent cock on the fuel injection pump closed except when air is vented, or it may cause the engine to stop. For fuel tanks that are lower than the injection pump. The fuel system must be pressurized by the fuel system electric fuel pump. If an electric fuel pump is not used, you must manually actuate the pump by lever to bleed. The primary fuel filter must be on the pressure side of the pump if the fuel tank is lower than the injection pump. To bleed, follow through above. Tighten air vent plug of the fuel injection pump except when bleeding, or it may stop the engine suddenly.

Checking the fuel pipes

Check the fuel pipes every 50 hours of operation. If the clamp band is loose, apply oil to the screw of the band, and tighten the band securely. If the fuel pipes, made of rubber, become worn out, replace them and clamp bands every 2 years. If the fuel pipes and clamp bands are found worn or damaged before 2 years pass, replace or repair them at once. After replacement of the pipes and bands, air-bleed the fuel system. When the fuel pipes are not installed, plug them at both ends with clean cloth or paper to prevent dirt from entering. Dirt in the pipes can cause fuel injection pump malfunction.

Cleaning the fuel filter pot

Every 100 hours of operation, clean the fuel filter in a clean place to prevent dust intrusion. Close the fuel filter lever. Remove the top cap, and rinse the inside with diesel fuel. Take out the element, and rinse it with diesel fuel. After cleaning, reinstall the fuel filter, keeping out of dust and dirt. Air-bleed the injection pump. Entrance of dust and dirt can cause a malfunction of the fuel injection pump and the injection nozzle. Wash the fuel filter cup periodically.

Fuel filter cartridge replacement

Replace the fuel filter cartridge with a new one every 400 operating hours. Apply fuel oil thinly over the gasket and tighten the cartridge into position by hand-tightening only. Finally, vent the air. Replace the fuel filter cartridge periodically to prevent wear of the fuel injection pump plunger or the injection nozzle, due to dirt in the fuel.

Checking oil level and adding engine oil

Check the engine oil level before starting or more than 5 minutes after stopping the engine. Remove the oil level gauge, wipe it clean and reinstall it. Take the oil level gauge out again, and check the oil level. If the oil level is too low, remove the oil filler plug, and add new oil to the prescribed level. After adding oil, wait more than 5 minutes and check the oil level again. It takes some time for the oil to drain down to the oil pan. Engine oil capacity - 7.5-9.5 L.

Kubota L2800, L3010, L3130 - Changing engine oil

Change oil after the initial 50 hours of operation and every 200 hours thereafter. Remove the drain plug at the bottom of the engine, and drain all the old oil. Drain oil will drain easier when the oil is warm. Add new engine oil up to the upper limit of the oil level gauge.

Replacing the oil filter cartridge

Replace the oil filter cartridge. Apply a film of oil to the gasket for the new cartridge. Screw in the cartridge by hand. When the gasket contacts the seal surface, tighten the cartridge enough by hand. Because, if you tighten the cartridge with a wrench, it will be tightened too much. After the new cartridge has been replaced, the engine oil level normally decreases a little. Thus, run the engine for a while and check for oil leaks through the seal before checking the engine oil level. Add oil if necessary.

Checking coolant level, adding coolant

Remove the radiator cap, after the engine has completely cooled, and check to see that coolant reaches the supply port. If the radiator is provided with a recovery tank, check the coolant level of the recovery tank. When it is between the "Full" and "Low" marks, the coolant will last for one day's work. When the coolant level drops due to evaporation, add water only up to the full level. Check to see that two drain cocks; one is at the crankcase side and the other is at the lower part of the radiator. If the radiator cap has to be removed, follow the caution and securely retighten the cap. If coolant should be leak, repair it or replace. Make sure that muddy or sea water does not enter the radiator. Use clean, fresh water and 50% anti-freeze to fill the recovery tank. Do not refill recovery tank with coolant over the "Full" level mark. Be sure to close the radiator cap securely. If the cap is loose or improperly closed, coolant may leak out and decrease quickly.

Kubota L2800, L3010, L3130 - Engine Components

Cylinder Head Surface Flatness

Clean the cylinder head surface. Put a straightedge on the cylinder head. Measure the clearance with a feeler gauge at the 6 places. If the measurement is more than the allowable limit, make it straight with a surface grinder. Cylinder head surface flatness - Allowable limit 0.05 mm / 0.002 in.

Cylinder Head Flaw

Prepare an air spray red check. Clean the surface of the cylinder head with detergent. Apply some red permeative liquid on the cylinder head surface. After you apply, do not touch it for 5 to 10 minutes. Clean away the red permeative liquid on the cylinder head surface with detergent. Apply the white developer on the cylinder head surface. If you found a red flaw, replace the cylinder head.

Valve Recessing

Clean the cylinder head surface, valve face and valve seat. Set the valve into the valve guide. Measure the valve recessing with a depth gauge. If the measurement is more than the allowable limit, replace the valve. If it stays more than the allowable limit after you replace the valve, replace the cylinder head. Valve recessing - 0.65 to 0.85 mm / 0.026 to 0.033 in.

Clearance between Valve Stem and Valve Guide

Remove carbon from the valve guide section. Measure the valve stem O.D. with an external micrometer. Measure the valve guide I.D. with a small hole gauge, and calculate the clearance. If the clearance is more than the allowable limit, replace the valves. If the clearance stays more than the allowable limit, replace the valve guide also. Clearance between valve stem and valve guide - 0.040 to 0.070 mm / 0.0016 to 0.0027 in. Valve stem O.D. - 7.960 to 7.975 mm / 0.3134 to 0.3139 in. Valve guide I.D. - 8.015 to 8.030 mm / 0.3156 to 0.3161 in.

Replacement of Valve Guide

Press out the used valve guide with the valve guide replacing tool. Clean the new valve guide and valve guide bore, and apply engine oil to them. Press fit the new valve guide with the valve guide replacing tool. Ream accurately the I.D. of the valve guide to the specified dimension. Valve guide I.D. (Intake and exhaust) - 8.015 to 8.030 mm / 0.3156 to 0.3161 in.

Correction of valve seat

Slightly correct the seat surface with a 1.0 rad (60°) or 0.79 rad (45°) valve seat cutter. Correct the seat surface with a 0.52 rad (30°) or 0.26 rad (15°) valve seat cutter. The width must be near the specified valve seat width (2.12 mm, 0.0835 in.). After you correct the seat, examine that the valve seating is flat. Apply a thin layer of compound between the valve face and valve seat, and lap them with a valve lapping tool. Examine the valve seating with Prussian Blue. The valve seating surface must show good contact on all sides.

Valve Lapping

Apply the compound equally to the valve lapping surface. Put the valve into the valve guide. Lap the valve on its seat with a valve lapping tool. After you lap the valve, clean away the compound and apply oil, then lap the valve again with oil. Apply Prussian Blue to the contact surface to measure the seated rate. If the seated rate is less than 70 %, lap the valve again.

Setting Load of Valve Spring

Put the valve spring on a tester. Compress the valve spring to the specified setting length. Read the compression load on the gauge. If the measurement is less than the allowable limit, replace the valve spring. Setting load / Setting length - 118 N / 35.0 mm, 12.0 kgf / 35.0 mm, 26.5 lbf / 1.38 in. Allowable limit - 100 N / 35.0 mm, 10.2 kgf / 35.0 mm, 22.5 lbf / 1.38 in.

Oil Clearance between Rocker Arm and Rocker Arm Shaft

Measure the rocker arm shaft O.D. with an external micrometer. Measure the rocker arm I.D. with an internal micrometer. Calculate the oil clearance. If the oil clearance is more than the allowable limit, replace the rocker arm and measure the oil clearance again. If the oil clearance stays more than the allowable limit, replace the rocker arm shaft also. Oil clearance between rocker arm and rocker arm shaft - 0.016 to 0.045 mm / 0.00063 to 0.0017 in. Rocker arm shaft O.D. - 13.973 to 13.984 mm / 0.55012 to 0.55055 in. Rocker arm I.D. - 14.000 to 14.018 mm / 0.55119 to 0.55188 in.

Oil Clearance between Tappet and Tappet Guide Bore

Measure the tappet O.D. with an external micrometer. Measure the tappet guide bore I.D. with a cylinder gauge. Calculate the oil clearance. If the oil clearance is more than the allowable limit or the tappet has a damage, replace the tappet. Oil Clearance between tappet and tappet guide bore - 0.020 to 0.062 mm / 0.00079 to 0.0024 in. Tappet O.D. - 23.959 to 23.980 mm / 0.94327 to 0.94409 in. Tappet guide bore I.D. - 24.000 to 24.021 mm / 0.94489 to 0.94570 in.

Kubota L2800, L3010, L3130 - Timing Gears

Side Clearance of Idle Gear

Set a dial indicator with its point on the idle gear. Move the idle gear to the front and rear to measure the side clearance. If the measurement is more than the allowable limit, replace the idle gear collar. Side clearance of idle gear - 0.15 to 0.25 mm / 0.0059 to 0.0098 in.

Hold the 2 end journals of camshaft with V blocks on the surface plate. Set a dial indicator with its point on the middle journal. Turn the camshaft slowly and read the variation on the indicator. If the measurement is more than the allowable limit, replace the camshaft. Kubota D1503/D1403 engine camshaft bend - Allowable limit 0.01 mm / 0.0004 in.

Cam Height

Measure the height of the cam at its highest point with an external micrometer. If the measurement is less than the allowable limit, replace the camshaft. Cam height of intake - 33.90 mm / 1.335 in. Cam height of exhaust - 33.90 mm / 1.335 in.

Oil Clearance of Camshaft Journal

Measure the camshaft journal O.D. with an external micrometer. Measure the cylinder block bore I.D. for the camshaft with a cylinder gauge. Calculate the oil clearance. If the oil clearance is more than the allowable limit, replace the camshaft. Oil clearance of camshaft journal - 0.050 to 0.091 mm / 0.0020 to 0.0035 in. Camshaft journal O.D. - 39.934 to 39.950 mm / 1.5722 to 1.5728 in. Cylinder block bore I.D. - 40.000 to 40.025 mm / 1.5748 to 1.5757 in.

Oil Clearance between Idle Gear Shaft and Idle Gear Bushing

Measure the idle gear shaft O.D. with an external micrometer. Measure the idle gear bushing I.D. with an internal micrometer. Calculate the oil clearance. If the oil clearance is more than the allowable limit, replace the bushing. If the oil clearance stays more than the allowable limit, replace the idle gear shaft also. Oil clearance between idle gear shaft and idle gear bushing - 0.025 to 0.066 mm / 0.00099 to 0.0025 in. Idle gear shaft O.D. - 37.959 to 37.975 mm / 1.4945 to 1.4950 in. Idle gear bushing I.D. - 38.000 to 38.025 mm / 1.4961 to 1.4970 in.

Replacement of Idle Gear Bushing

Press out the used idle gear bushing with the replacing tool. Clean a new idle gear bushing and idle gear bore, and apply engine oil to them. Press fit the new bushing with the replacing tool. Make sure that the bushing end aligns the end of the idle gear.

Kubota L2800, L3010, L3130 - Piston and Piston Rings

Piston Pin Bore I.D.

Measure the piston pin bore I.D. in the horizontal and vertical directions with a cylinder gauge. If the measurement is more than the allowable limit, replace the piston. Piston pin bore I.D. - 25.000 to 25.013 mm / 0.98426 to 0.98476 in.

Oil Clearance between Piston Pin and Small End Bushing

Measure the piston pin O.D. where it touches the bushing with an external micrometer. Measure the small end bushing I.D. with an internal micrometer. Calculate the oil clearance. If the oil clearance is more than the allowable limit, replace the bushing. If the oil clearance stays more than the allowable limit, replace the piston pin also. Oil clearance between piston pin and small end bushing - 0.014 to 0.036 mm / 0.00056 to 0.0014 in. Piston pin O.D. - 25.004 to 25.011 mm / 0.98441 to 0.98468 in. Small end bushing I.D. - 25.025 to 25.040 mm / 0.98524 to 0.98582 in.

Piston Ring Gap

Put the piston ring into the lower part of the liner with the piston. Measure the ring gap with a feeler gauge. If the ring gap is more than the allowable limit, replace the ring. Top ring - 0.20 to 0.35 mm / 0.0079 to 0.013 in. Second ring - 0.30 to 0.45 mm / 0.012 to 0.017 in. Oil ring - 0.20 to 0.40 mm / 0.0079 to 0.015 in.

Clearance between Piston Ring and Groove

Clean the rings and the ring grooves, and install each ring in its groove. Measure the clearance between the ring and the groove with a feeler gauge or depth gauge. If the clearance is more than the allowable limit, replace the piston ring. If the clearance stays more than the allowable limit with new ring, replace the piston also. Top ring - 0.050 to 0.090 mm / 0.0020 to 0.0035 in. Second ring - 0.0780 to 0.110 mm / 0.00307 to 0.00433 in. Oil ring - 0.030 to 0.070 mm / 0.0012 to 0.0027 in.

Kubota L2800, L3010, L3130 - Crankshaft

Oil Clearance between Crankpin and Crankpin Bearing

Clean the crankpin and crankpin bearing. Put a strip of plastigauge on the center of the crankpin. Install the connecting rod cap and tighten the connecting rod screws to the specified torque, and remove the cap again. Measure the width that it becomes flat with the scale to get the oil clearance. If the oil clearance is more than the allowable limit, replace the crankpin bearing. If the same dimension bearing is not applicable because of the crankpin wear, replace it with an undersize one. Oil clearance between crankpin and crankpin bearing - 0.025 to 0.087 mm / 0.00099 to 0.0034 in. Crankpin O.D. - 46.959 to 46.975 mm / 1.8488 to 1.8494 in. Crankpin bearing I.D. - 47.000 to 47.046 mm / 1.8504 to 1.8522 in.

Oil Clearance between Crankshaft Journal and Crankshaft Bearing 1

Measure the O.D. of the crankshaft journal with an external micrometer. Measure the I.D. of the crankshaft bearing 1 with an internal micrometer. Calculate the oil clearance. If the oil clearance is more than the allowable limit, replace the crankshaft bearing 1. If the same dimension bearing is not applicable because of the crankshaft journal wear, replace it with an undersize one. Oil clearance between crankshaft journal and crankshaft bearing 1 - 0.0400 to 0.118 mm / 0.00158 to 0.00464 in. Crankshaft journal O.D. - 59.921 to 59.940 mm / 2.3591 to 2.3598 in. Crankshaft bearing 1 I.D. - 59.980 to 60.039 mm / 2.3615 to 2.3637 in.

Replacement of Crankshaft Bearing 1

Press out the used crankshaft bearing 1 with the replacing tool. Clean a new crankshaft bearing 1 and crankshaft journal bore, and apply engine oil to them. Make sure that the seam of the new bearing 1 points to the exhaust manifold side. Then press fit the new bearing 1 with the replacing tool.

Oil Clearance between Crankshaft Journal and Crankshaft Bearing 2

Put a strip of plastigauge on the center of the journal. Install the bearing case and tighten the baring case screws 1 to the specified torque, and remove the bearing case again. Measure the width that it becomes flat with the scale to get the oil clearance. If the oil clearance is more than the allowable limit, replace the crankshaft bearing 2. If the same dimension bearing is not applicable because of the crankshaft journal wear, replace it with an undersize one. Oil clearance between crankshaft and crankshaft bearing 2 - 0.0400 to 0.104 mm / 0.00158 to 0.00409 in. Crankshaft journal O.D. - 59.921 to 59.940 mm / 2.3591 to 2.3598 in. Crankshaft bearing 2 I.D. - 59.980 to 60.025 mm / 2.3615 to 2.3631 in.

Replacement of Crankshaft Sleeve

Remove the used crankshaft sleeve. Set the sleeve guide to the crankshaft. Set the stopper to the crankshaft. Increase the temperature of a new sleeve to between 150 and 200C (302 and 392F). Install the sleeve to the crankshaft with the auxiliary socket for pushing. Make sure that the large chamfer of the sleeve points to outward. If the temperature of the sleeve is not enough to install, the sleeve can get a damage when you install.

Replacement of Bearing Case Cover Oil Seal

Remove the used oil seal by using appropriate tool and be careful not to scratch the bearing case cover. Clean a new oil seal and bearing case cover. Set the bearing case cover on the replacing tool and fix it with bolts. Apply a layer of engine oil to the seal outer periphery. Install the oil seal into the bearing case cover by using the replacing tool, until it is flash with the bearing case cover.

Kubota L2800, L3010, L3130 - Electrical System Checking

Glow Plug Lead Terminal Voltage

Disconnect the wiring lead from the glow plug after turning the main switch off. Turn the main switch key to the ON position, and measure the voltage between the lead terminal and the chassis. Turn the main switch key to the START position, and measure the voltage between the lead terminal and the chassis. If the voltage at either position differs from the battery voltage, the wiring harness or main switch is faulty.

Glow Plug Continuity

Disconnect the lead from the glow plugs. Measure the resistance between the glow plug terminal and the chassis. If 0 is indicated, the screw at the tip of the glow plug and the housing are short-circuited. If the factory specification is not indicated, the glow plug is faulty.

Glow Relay

Connector Voltage - Turn the main switch off. Disconnect the 4P connector from glow relay. Measure the voltage across the terminal 3 (Positive) and chassis (Negative). If the voltage differs from the battery voltage, the wiring harness is faulty. Turn the main switch on. Measure the voltage across the terminal 1 (Positive) and chassis (Negative). If the voltage differs from the battery voltage, the wiring harness is faulty. Glow Relay Test - Remove the glow relay. Apply battery voltage between the terminal 3 and the terminal 4, and check the continuity of the terminal 1 and the terminal 2. If the continuity is not established between terminal 1 and the terminal 2, replace the glow relay.

Engine Stop Solenoid

Disconnect the 2P connector from engine stop solenoid. Turn the main switch key to the ON position. Measure the voltage between the terminal 1, terminal 2 and body. If the voltage differs from the battery voltage, the wiring harness or main switch is faulty.

Stop Solenoid Coil

Disconnect the 2P connector from engine stop solenoid. Measure the resistance between the terminal 1, terminal 2 and body. If the resistance differs from the factory specification, the coil is faulty.

Engine Stop Solenoid Relay

Connector Voltage - Turn the main switch off. Disconnect the 4P connector from engine stop solenoid relay. Measure the voltage between the terminal 3 (Positive) and chassis (Negative). If the voltage differs from the battery voltage, the wiring harness is faulty. Turn the main switch on. Measure the voltage between the terminal 1 (Positive) and chassis (Negative). If the voltage differs from the battery voltage, the wiring harness is faulty. Engine Stop Solenoid Relay - Remove the engine stop solenoid relay. Apply battery voltage between the terminal 3 and the terminal 4, and check the continuity of the terminal 1 and the terminal 2. If the continuity is not established across terminal 1 and 2, replace the engine stop solenoid relay.