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Massey Ferguson 230, 235, 240, 245, 250 - Hydraulic system

MF 230, 235, 240, 245, 250 Tractors Repair Operations

Hydraulic system types

Two different types of hydraulic systems have been used, and identifiestion of the type of system must be established before proceeding with adjustments or repairs. One type of system has a dashpot attached to the lift cover, and lift cover has casting number 1861 320 Ml. The other type of system does not use a dashpot. Either system may or may not have provisions for pressure control. On Massey Ferguson 230, 235, 240, 245, 250 models, hydraulic lift system consists of a pto driven piston type pump, which is mounted within the differential housing beneath the lift cover, and a single acting hydraulic cylinder which actuates the rockshaft and lift arms. A gear type auxiliary pump is optionally added to supply operating fluid to MultiPower clutches, ipto clutches and/or auxiliary hydraulic cylinder applications. Auxiliary pump is located directly above lift system pump, and is driven by a gear train mounted to front of pumps.

Reservoir and filter - The transmission/differential lubricant is the operating fluid for the MF 230, 235, 240, 245, 250 hydraulic system. Manufacturer recommends renewing hydraulic oil after every 500 hours of operation, or annually, whichever comes first. The hydraulic pump strainer/filter, located in bottom of differential housing, should be removed and cleaned after every 500 hours of operation. Note that oil must be drained from housing before removing filter. Filter element can be cleaned using solvent and compressed air. Renew filter element if damaged or if it cannot be thoroughly cleaned. Some models are also equipped with an auxiliary hydraulic filter located on left-hand side of the differential housing. Auxiliary filter element should be renewed after every 500 hours of operation.

Troubleshooting

The following are symptoms which may occur during operation of Massey Ferguson 230, 235, 240, 245, 250 hydraulic lift system and their possible causes. Use this information to isolate the cause of the problem before proceeding with component disassembly.

Hitch will not raise. Could be caused by: Leak in system. Remove response control side cover and check for internal leakage. Damaged, binding or misadjusted control valve linkage. Misadjusted or faulty servo valve (pressure control units), or faulty safety relief valve (nonpressure control units). Faulty hitch lift pump.

Lift links raise unevenly or jerky. Could be caused by: Valve sticking in pump valve chamber.

Lift links will not raise to full height. Could be caused by: Transport stop misadjusted. Control valve misadjusted. Control linkage misadjusted.

Lift links will not lower. Could be caused by: Control valve sticking. Control valve misadjusted. Lift arms binding.

Hitch lowers too fast with response control at "SLOW" position. Could be caused by: Response control misadjusted. Control linkage binding or damaged. Faulty dashpot (if so equipped).

Erratic action when operating in draft control. Could be caused by: End play in master control spring. Control linkage binding or damaged.

Lift links creep down. Could be caused by: Internal leakage in cylinder, control valve or valve chambers.

System checks

Before beginning system checks, be sure oil level is at full mark on dipstick, and test system only after oil has reached operating temperature of approximately 50C (120F). Connect a 35000 kPa (5000 psi) pressure gage at test port in lift cover. Move the response control lever to FAST and the inner quadrant lever to TRANSPORT. If system is pressure control type, make sure that transport stop is fully rearward directly beneath PRESSURE range of inner quadrant. If system is nonpressure type, check that center of rear bolt holding transport stop is 11 mm (7/16 inch) from rear of quadrant stop. On MF 230, 235, 240, 245, 250 models, check to be sure lever friction springs are compressed to 20.6 mm (13/16 inch). This amount of compression should permit levers to slide freely, but should hold position when released.

Transport stop - To check transport stop adjustment, proceed as follows: Run engine at 1000 rpm and move draft control lever to full UP position. If pressure control type, move inner quadrant lever to CONSTANT PUMPING range forward of the transport stop. Scribe a line across lift arm hub and Lift cover casting. Move inner lever forward in POSITION control range to lower the lift links, then move lever back against the transport stop. Measure the distance that scribe lines are separated. If nonpressure control style, move inner quadrant lever fully UP in quadrant past the transport stop. Scribe a line across lift arm hub and lift cover casting, then move inner lever back to transport stop. Measure distance that scribed lines are separated. On Massey Ferguson 230, 235, 240, 245, 250 models, distance between scribed lines should be 3.2-3.9 mm (1/8-5/32 inch). If dimension is not correct, adjust transport stop before proceeding with further tests.

Draft control - To check draft control, run engine at low idle speed. Move inner quadrant lever against transport stop and operate draft control lever to raise the lift arms. With draft control lever fullly UP, gage pressure should not be excessive and servo relief (or safety relief ) valve should not be opening. If lift links do not move to full transport or through full range, transport stop may be adjusted incorrectly, lift cover internal linkage may be misadjusted or control valve may be sticking. If servo relief is opening, the transport stop, lift cover linkage or pressure control valve (if so equipped) may be incorrectly adjusted. Position draft control lever between the sector marks (M) on draft quadrant while leaving inner quadrant lever at TRANSPORT. The lift links should remain at a midposition with draft lever within 6.3 mm (1/4 inch) of either sector mark.

Position control - Check position control, first attach a fully mounted implement to 3-point linkage. Place draft control lever to full UP position and response control lever in FAST position. Run engine at low speed and operate inner lever in POSITION control range to fully raise and lower lift links several times. It must be possible to fully raise and lower lift links and to position them in any intermediate setting. If lift links do not raise or lower fully, perform the installed adjustments. If lift links creep down then up again (hunt), internal leakage is indicated in control valve, valve chambers, pump pistons or lift cylinder seal rings. Move inner quadrant lever to TRANSPORT. The lift links should raise to transport position without reaching maximum system pressure. If lift links do not reach transport position or if maximum system pressure is obtained, refer to adjustment procedures.

Master control spring sensitivity - To check sensitivity of control spring, first attach a fully mounted implement to lower links and top link. Place inner quadrant lever in TRANSPORT. Operate engine at low rpm and move draft control lever to raise implement to approximately midpoint of lift travel (implement must be clear of ground). Apply a downward force to rear of implement. System should respond by lowering implement slightly. Apply an upward force to rear of implement. System should raise implement as long as upward force is being applied.

Response control - To check operation of response control, first attach a fully mounted implement to 3-point links. Place inner quadrant lever in TRANSPORT. Operate engine at low rpm and move draft control lever to full UP position. Move response control lever to SLOW position, then move draft control lever rapidly to full DOWN position. The implement should hesitate slightly, then lower at a moderate rate of speed. Place response lever in FAST position. Repeat lowering test using draft control lever to raise implement, then quickly move control lever to DOWN position. The implement should lower noticeably quicker with response lever in FAST position than previous check with lever in SLOW position.

Pressure control - To check operation of pressure control valve (if so equipped), attach an implement or weight to lift links. Run engine at 1000 rpm, move draft control lever to full UP position, move inner quadrant lever to full HIGH (constant pumping) in pressure control range of quadrant and observe pressure indicated on gage. Pressure should be 17230-17930 kPa (2500-2600 psi). Move inner lever to full LOW position and observe gage reading. Pressure should be 0-500 kPa (0-75 psi). Move inner lever to just raise implement and place a load on hydraulic system. Pressure indicated on gage should not fluctuate more than 700 kPa (100 psi) with implement held steady at a selected height. lf pressures are not as described, refer to adjustment procedure.

Adjustment

Master control spring - To adjust master control spring, disconnect control beam or top link (depending on what type spring head is used) from spring head. If a clevis type head is used,remove bolts attaching clevis rocker link to lift cover casting. Position draft control lever fully down. Check for end play in spring by pulling and pushing on spring head. If end play is present, loosen set screw in side of lift housing and pull back rubber boot to expose adjusting nut. Turn adjusting nut into or out of lift cover until end play is just eliminated. End play will be present if adjustlng nut is either too loose or too tight. If end play cannot be elimmaled by turning adjusting nut, it will be necessary to remove control spring assembly and check internal adjustment of spring as follows: Unscrew adjusting nut and withdraw spring assembly from lift cover. Grasp spring while holding head and attempt to rotate spring on plunger. Spring should fit snugly with no end play, but should still turn with moderate effort. If adjustment is incorrect, drive pin out of head and thread plunger into or out of head until end play is just eliminated. Tighten plunger further, if necessary, until slot is aligned and reinstall pin. Install control spring assembly into housing and turn adjusting nut until end play is just eliminated. Install nylon plug and tighten set screw.

Installed adjustments - The following adjustments should be performed with lift cover installed and Massey Ferguson 230, 235, 240, 245, 250 tractor operational. Accomplish the adjustments in the sequence listed. Remove the response control cover plate from right side. Be sure that oil is maintained at level of lowest threaded mounting hole for response control cover making it necessary to temporarily reinstall the lower cap screw. Be sure that control valve adjusting screw and roller are correctly installed. If pressure control type, adjusting screw should be threaded into vertical lever, but should not contact diaphragm plunger. On all models, make sure lift arms will fall freely of their own weight from raised position with engine not running and quadrant lever down. Side play of lift arms should be the least possible while still permitting free movement, and is adjusted by cap screws securing lift arms to shaft. Check control spring adjustment and adjust if necessary. Set initial position of transport stop and lever friction. Connect a 35000 kPa (5000 psi) pressure gage to port in lift cover. Attach an implement or 400 Kg (900 pound) weight to lift links. Operate engine and raise and lower weight several times to expel air and warm oil to about 50C (120F). Lower lift links and stop engine.

Control valve - To adjust control valve, first move both quadrant levers to TRANSPORT position. Then, install a wedge between dashpot piston rod and collar to hold dashpot and linkage in neutral position during adjustment. Be careful when positioning wedge and do not dislodge roller from control lever, or vertical lever from Its pivot pin. Start engine and run at low idle, move draft control lever fully down and turn adjusting screw INTO lever until lift links just begin to rise. Turn adjusting screw OUT after links are just above horizontal so lift links stop rising. This will synchronize pump control valve and internal linkage at neutral position. Push the control lever (with roller) forward to lower if lift links raise too high (above horizontal), then readjust screw. Shut off engine and move draft control lever to TRANSPORT, then remove adjustment wedge.

Transport stop - Adjust transport stop with weights still attached to lift links. Run engine at idle speed with draft control lever in full UP position. On nonpresure control models, move inner quadrant lever past the transfer stop bracket full up on quadrant. Be sure relief valve is opening, then scribe lines across lift arms and lift cover. Move the inner quadrant control lever (position control) down toward transport until scribed lines are 3.2-3.9 mm (1/8-5/32 inch) apart. Adjust transport stop to hold control lever at this point on quadrant. If stop adjustment is impossible, lift cover internal linkage may be incorrectly adjusted, damaged or binding. Check linkage through right side opening. Also check relief valve operation through this opening. On pressure control models, move inner quadrant lever into CONSTANT PUMPING range at PRESSURE control side of transport stop, then scribe a line across lift arm and lift cover hub. Move inner quadrant lever to POSITION side of transport stop, firmly against stop pin. Measure distance between the scribed lines. If not within 3.2-3.9 mm (1/8-5/32 inch), loosen control quadrant mounting bolts and move only the inner quadrant to correct the setting.

Draft control - Adjust draft control as follows: Disconnect top link, but leave weight or implement attached to lower links. Run MF 230, 235, 240, 245, 250 engine at idle speed. Move inner quadrant lever to TRANSPORT position and move draft control lever downward until weight just begins to fall. Position draft lever so weight remains suspended in approximately midposition, then note location of lever. If draft lever is not within 6.4 mm ( 1/4 inch) of sector marks, loosen screws securing draft quadrant and relocate quadrant until sector marks are correctly located. Tighten retaining screws, then recheck adjustment.

Pressure control - To adjust pressure control, proceed as follows: Implement or weight must be attached to lift links and pressure gage connected to lift cover. Run engine at low speed and move draft. control lever fully UP. Move inner quadrant lever forward as far as possible, then move lever rearward into CONSTANT PUMPING and note pressure gage reading. If pressure is not within 17240-17930 kPa (2500-2600 psi), move inner lever fully down and acljust pressure control valve tube (accessible through response cover opening). Turn tube clockwise to increase, or counterclockwise to decrease pressure to recommended setting. When pressure is within limits, turn pressure control adjusting screw clockwise until vertical lever begins to pulsate, then turn screw counterclockwise until pulsating stops and pressure does not fluctuate more than 700 kPa (100 psi).

Response control - To adjust response control, loosen plunger set screw, push rod down, then retighten set screw to hold rod in place. Move the response control lever to FAST position, then reinstall response side cover (without outer cover) onto housing. Move response control lever to place it about 6.4 mm (1/4 inch) from SLOW position. Remove access plug from side cover. Insert a wrench through access opemng and loosen set screw to allow plunger to release and contact response lever shaft. Retighten set screw. Install access plug and outer cover. Fill housing to full mark on dipstick with recommended oil. Start engine and raise and lower lift links several times using draft control lever to purge air from dashpot. Check for proper operation of hitch.