Specifications, Service and Repair of Farm and Lawn Tractors

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Massey Ferguson 230, 235, 240, 245, 250 diesel engine - Cooling system and fuel system


Cooling system

Radiator - Remove radiator, first drain the cooling system. Remove hood and side panels. Remove radiator support strap. Remove fan shroud retaining screws and move shroud rearward. Disconnect top and bottom hoses from radiator. Remove cap screws attaching radiator to grille housing and remove the two retaining nuts from underneath front axle support. Lift radiator from Massey Ferguson 230, 235, 240, 245, 250 tractor. Reinstall, reverse the removal procedure. Thermostat - The thermostat is contained in a housing under the coolant outlet elbow. Thermostat should begin to open at 81-84C (177-183F) and should be fully open at 98C (208F).

Water pump - Remove water pump, first drain cooling system. On MF 240, 250, remove radiator. On all models, remove fan and fan belt. Disconnect hoses from pump, remove pump mounting cap screws and remove pump assembly. Disassemble, remove back cover plate. Remove pulley hub using a suitable puller. Press shaft and bearing assembly with impeller rearward from pump housing. Press shaft out of the impeller. Remove seal assembly and slinger. Inspect all parts for wear or damage and renew if necessary. Be sure to renew seal assembly. Reassemble, press shaft and bearing assembly into housing until front face of bearing is flush with front of housing. Be sure shorter end of shaft is towards front of housing. Install slinger with flange towards bearing assembly. Install front part of seal with carbon face of seal facing rearward. Install ceramic faced seal with grooved side towards the impeller. Support front end of shaft, then press impeller onto shaft until clearance between front of impeller blades and pump housing is 0.25-0.50 mm (0.010-0.020 inch). Support rear end of shaft (not the impeller), place pump mounting cap screws into holes in housing, then press pulley hub onto shaft. Distance from gasket surface to fan surface of pulley flange should be 140.5 mm (5.530 inches). Make certain shaft assembly rotates smoothly. Reinstall water pump by reversing the removal procedure. Adjust fan belt tension to provide 13-19 mm (1/2 to 3/4 inch) deflection with 66 N (15 pounds) force applied midway between longest span between pulleys.

Diesel fuel system

Massey Ferguson 230, 235, 240, 245, 250 diesel fuel system consists of three basic units; the fuel tank and filters, injection pump and injector nozzles. When servicing any unit associated with the diesel fuel system, the maintenance of absolute cleanliness is of utmost importance. Of equal importance is the avoidance of nicks or burrs on any of the working parts. Fuel filters - Models MF 230, 235, 245 are equipped with a single fuel filter. Two fuel filters, a primary and secondary, are used on Models MF 240, 250. A glass sediment bowl is located at the bottom of the primary or single filter element. Bowl should be inspected and any dirt or water accumulation drained daily. If substantial amount of water or other contamination is evident, source of contamination should be found and corrected. Manufacturer recommends renewing fuel filter element(s) after every 500 hours of operations or annually, whichever comes first. Filter elements should also be renewed if loss of engine power or uneven running is noticeable regardless of hours of operation. Note that cleanliness of fuel supply has more efectf on the life offuel filters than hours of operation. Thoroughly clean fuel filter and surrounding area prior to removal. Close fuel tank shut-off valve. Remove center cap screw from fuel filter head and remove filter element. Install new element using new gaskets. Open fuel shut·off valve and bleed air from system.

Bleeding fuel system - To bleed air from fuel system, first make sure fuel shut-off valve is open and move injection pump shut-off control to Run position. Loosen air vent plug in top of filter head, then operate lift pump priming lever until air free fuel flows from vent. Tighten vent plug. It may be necessary to rotate crankshaft to change position of camshaft lobe In relation to lift pump actuating arm to allow operation of priming lever. Loosen vent plug on secondary filter (if so equipped) and repeat bleeding procedure. Open vent plugs on injection pump and operate lift pump priming lever. Tighten lower plug then upper plug as air-free fuel flows from each vent. Note that air in governor housing relieved by bleed screw will not prevent engine from starting and running properly; however, condensation in the trapped air can cause rusting of governor components and eventual pump malfunction. Loosen Thermostart fuel supply line (Massey Ferguson 230, 235, 240, 245, 250 tractors so equipped) at intake manifold and operate lift pump priming lever until fuel flows from the line. Retighten fuel line connection. If engine fails to start at this point, loosen high pressure fuel line connections at injectors. With hand throttle in full speed position, crank engine with starter motor until fuel flows from the connections. Retighten fuel line connections and start engine.

Thermostart system - The Thermostart system is available as an aid for cold weather starting on late production MF 250 tractors. The system consist of an electrically actuated heater located in the intake manifold. The unit heats and ignites diesel fuel vapor in intake manifold to warm the air going into the cylinders. The system is actuated by turning the starter switch to Heat position for 15 to 20 seconds, then turn key to Heat/Start position and crank engine. After engine struts, key can be returned to Heat position until engine runs smoothly or for a maximum of 15 seconds. Release the key when engine is running smoothly. If Thermostart unit does not operate properly, check for voltage at intake manifold wiring connector while holding key switch in Heat position. If voltage is not present, check wiring and switch. If voltage is reaching Thermostart unit, disconnect fuel line and check for restricted fuel flow. If fuel is flowing to Thermostart unit, remove the unit, inspect and renew as necessary.

Fuel lift pump - The fuel lift pump is operated by an eccentric on Massey Ferguson 230, 235, 240, 245, 250 engine camshaft. Output delivery pressure should be 41-69 kPa (6-10 psi). Scribe marks across cover and body before disassembling to ensure correct alignment when reassembling. Diaphragm is disconnected from lever by pushing it into pump body and turning it 90 degrees. A repair kit containing check valves, diaphragm and actuating link components is available for servicing lift pump. Bleed air from system after reinstalling pump. Injector nozzles - All diesel models are equipped with C.A.V. multihole nozzles which extend through the cylinder head to inject the fuel charge directly into combustion chamber. Different injectors have been used. See identification code letters stamped on nozzle holder when servicing injectors. Do not intermix different types of injectors. If rough or uneven engine operation or misfiring indicates a faulty injector, the defective unit can usually be located as follows: With engine running at the speed where malfunction is most noticeable, loosen the compression nut on high pressure line for each injector in turn so fuel is discharged at the loosened connection. Note change in engine, if any, and retighten connection. The faulty unit is the one which least affects the running of engine when its line is loosened. If a faulty nozzle is found and considerable time has elapsed since the injectors have been serviced, it is recommended that all nozzles be removed and serviced or that new or reconditioned units be installed.

Remove and reinstall - Before loosening any fuel lines, thoroughly clean the lines, connections, injectors and engine area surrounding the injector with air pressure and solvent spray. Disconnect the fuel leak-off line and pressure line from the injector. Cap all connections as they are loosened to prevent dirt entry into the system. Remove the two stud nuts and withdraw injector unit from Massey Ferguson 230, 235, 240, 245, 250 cylinder head. Thoroughly clean the nozzle recess in cylinder head before reinstalling injector unit. It is important that seating surface be free of even the smallest particle of carbon or dirt which could cause the injector unit to be cocked and result in blow by. No hard or sharp tools should be used in cleaning. Do not reuse the copper sealing washer located between injector nozzle and cylinder head, always install a new washer. Be sure only one copper sealing washer is in place when installing the injector. Each if injector should slide freely into place in cylinder bead without binding. Make sure dust seal is reinstalled and tighten the retaining stud nuts evenly to a torque of 14-16 Nm (10-12 fl-lbs.).

Testing

A complete job of testing and adjusting the injector requires the use of special test equipment. Only clean, approved testing oil should be used in the lest tank. The nozzle should be tested for opening pressure, seat leakage, back leakage, and spray pattern. When tested, the nozzle should open with a sharp popping or buzzing sound and cut off quickly at end of injection with a minimum of seat leakage and controlled amount of back leakage. Before conducting test, operate tester lever until fuel flows from tester line, then attach the injector. Pump tester lever a few quick strokes to clear air from tester line and injector and to make sure nozzle valve is not stuck or spray holes plugged. Opening pressure - Open valve to tester gage and operate tester lever slowly while observing gage reading. Opening pressure should be as follows: Nozzle Identification Code EE - Setting Pressure With New Spring - 19235 kPa (2790 psi) / Normal Operating Pressure - 17720 kPa (2570 psi). Nozzle Identification Code ON or FS - Setting Pressure With New Spring - 18755 kPa (2720 psi) / Normal Operating Pressure - 17240 kPa (2500 psi). Nozzle Identification Code GM - Setting Pressure With New Spring - 18755 kPa (2720 psi) / Normal Operating Pressure - 17720 kPa (2570 psi). If opening pressure is not as specified, remove the injector cap nut and turn adjusting screw as required to obtain recommended pressure. When adjusting a new injector or overhauled injector with new pressure spring (4), set pressure to the recommended higher pressure to allow for Initial pressure loss due to spring taking a set.

Seat leakage - To check for leakage at nozzle valve seat, wipe nozzle tip dry. Operate tester lever slowly to maintain gage pressure at 1000 kPa (150 psi) below nozzle opening pressure. Hold test pressure for 10 seconds; if fuel appears on nozzle tip, the valve is not seating and injector must be overhauled or renewed. Back leakage - If no external leakage was noted in seat leakage test, check for back leakage as follows: Bring gage pressure to about 16000 kPa (2300 psi), close tester return valve and release tester lever. Observe the time required for gage pressure to drop from 15170 kPa (2200 psi) to 10135 kPa (1470 psi). For a nozzle in satisfactory condition, this time should not be less than six seconds. A faster pressure drop indicates a worn or scored nozzle valve assembly, and nozzle valve should be renewed. Leakage of the tester check valve or connections will cause a false reading, showing up In this test as excessively fast leak-back. If all Injectors tested fall to pass this test, the tester rather than the units should be suspected as faulty. Spray pattern - If leakage and pressure are as specified when tested as outlined in previous operate tester handle several times while observing spray pattern. Four finely atomized, conical sprays should emerge from nozzle tip with equal penetration into surrounding atmosphere. Spray pattern is not symmetrical with centerline of nozzle up. The apparently irregular location of nozzle holes is designed to provide the correct spray pattern in the combustion chamber.

Overhaul - Hard or sharp tools, emery cloth, grinding compound, or other than approved solvents or lapping compounds must never be used. An approved nozzle cleaning kit is available through any C.A.V. Service Agency and other sources. Wipe all dirt and loose carbon from exterior of nozzle and holder assembly. It is recommended that injectors be soaked in a suitable carbon cleaning solution for several hours, or overnight if possible, prior to disassembly; otherwise, nozzle valve body may turn with nozzle nut shearing the locating dowel pins. Secure nozzle bolder in a soft-jawed vise or holding fixture, then remove cap nut. Remove adjusting screw, spring and spindle. Unscrew nozzle nut and remove nozzle valve assembly. Nozzle valve and body are matched assemblies and must not be intermixed. If more than one injector is to be disassembled, keep parts of each injector separate from the others by placing in a compartmented pan containing clean diesel fuel. Clean injector exterior using a brass wire brush. Soak in a suitable carbon solvent, if necessary, to loosen hard carbon deposits. Rinse parts in clean diesel fuel or calibrating oil after cleaning to neutralize the carbon solvent and prevent etching of polished surfaces. Use a pin vise with correct size cleaning wire to clean nozzle spray holes. Cleaning wire should be slightly smaller than spray holes. On nozzles with EE identification code, spray hole diameter is 0.28-0.30 mm. On all other nozzles, spray hole diameter is 0.25-0.27 mm (0.010-0.0105 inch). Clean nozzle body seat and fuel passages using appropriate tools from cleaning kit. All polished surfaces should be relatively bright without scratches or dull patches. Nozzle valve must slide freely in valve body. If valve sticks, reclean or renew valve assembly as necessary. Before reassembling, thoroughly rinse all parts in clean diesel fuel and make sure all carbon deposits have been removed. Assemble parts while wet with diesel fuel. Tighten nozzle nut to 68 Nm (50 ft.-lbs.) torque. Retest and adjust the assembled injector.

Injection pump

Adjustment - The injection pump is a sealed unit and no service work of any kind should be attempted on the pump or governor unit without the use of special pump testing equipment and special training. The only authorized adjustment is of the low idle speed screw. If additional service work is required, the pump should be turned over to an authorized C.A.V. service station for overhaul. Inexperienced or unequipped service personnel should never attempt to overhaul a diesel injection pump. The low idle speed adjusting screw should be adjusted with engine warm and running, to provide the recommended slow idle speed of 725-775 rpm. Check to make sure that governor arm contacts the low idle adjustmg screw and maximum speed adjusting screw when throttle lever is moved to slow and fast positions. Also check to make sure stop lever moves fully to operating position when stop button is pushed in, and shuts off fuel to injectors when stop button is pulled. The maximum speed adjusting screw is set at the factory and the adjustment is sealed. High idle (no-load) speed should be 2135-2185 on Massey Ferguson 230, 240 models. 2200-2300 on MF 230, 240 models and 2400-2450 on MF 235, 245, 250 tractors.

Pump static timing - Check pump timing, shut off fuel at fuel tank. Remove timing window cover from injection pump and remove engine timing window plug from lefl side of flywheel housing adapter plate. Turn crankshaft until No. 1 (front) piston is coming up on compression stroke and the correct degree mark for static turning is aligned in flywheel timing window; 16 degrees BTDC for MF 245, 250, 24 degrees BTDC for MF 230, 235, 240. At this point the E mark on injection pump rotor should align with square end of snap ring. If E mark is slightly out of alignment with end of snap ring, the mounting holes in pump flange are elongated to permit minor timing variations. If it is necessary to move pump, check alignment of timing marks on pump flange and timing gear case and scribe new lines as necessary. If E mark cannot be aligned by shifting pump on mounting studs, either the No. 1 piston is not on compression stroke or engine timing gears are not timed correctly.

Remove and reinstall - The injection pump drive shaft has a milled slot in forward end which engages the dowel pin in pump drive gear. The injection pump drive gear cannot become unmeshed from idler gear with timing gear cover in place. Therefore, injection pump can be removed and reinstalled without regard to timing position. Before removing the injection pump, thoroughly wash the pump and fuel line connections. Immediately plug all openings in fuel system as lines are disconnected to prevent entry of dirt. Disconnect throttle rod and stop cable or rod from pump. Shut off fuel, then disconnect fuel inlet, return and high pressure lines from pump. Remove inspection cover from front of timing gear cover, then remove three cap screws attaching injection pump drive gear to pump shaft. Remove pump flange stud nuts, then withdraw pump. To reinstall pump, align milled slot in pump shaft with dowel and insert pump. Align timing marks on pump flange and timing gear case, then tighten stud nuts. Pump can only be installed in one position. If timing gear train has not been disturbed and timing marks are aligned, timing should be correct. Complete installation by reversing the removal procedure. Check pump timing. Bleed air from system.

 

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