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Massey Ferguson 230, 235, 240, 245, 250 - Hydraulic lift cover

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

Remove and reinstall

To remove hydraulic lift cover, first remove seat and seat frame. Disconnect upper lift links from lift arms and remove center link. On models so equipped, remove control beam from control spring head. On Massey Ferguson 230, 235, 240, 245, 250 tractors, drain hydraulic system fluid down until response control side cover can be removed. Reaching through side cover opening, spread pump control valve lever arms and remove roller. Remove transfer plate or auxiliary valve. Remove lift cover mounting cap screws, then carefully remove cover using a suitable hoist. When reinstalling lift cover, it is recommended that two guide dowels be installed to aid in aligning cover with differential housing. Be sure to guide the hydraulic standpipe into lift pump as cover is lowered onto housing. Be sure vertical control lever is located to the rear of control valve lever. Reinstall roller in control valve lever. Tighten lift cover cap screws to 75 Nm (55 ft-lbs.) torque. Complete installation by reversing the removal procedure.

Overhaul

To disassemble, first unscrew control spring adjusting nut and withdraw control spring assembly from MF 230, 235, 240, 245, 250 lift cover. Remove dashpot assembly. If equipped with pressure control, remove diaphragm, pressure control valve and pressure control lever. Remove adjusting bolt. Remove return spring. Remove set screw securing control quadrant in lift cover. Hold draft and position levers away from quadrant cams, then remove quadrant assembly from lift cover. Compress springs, then install cotter pins through holes in ends of spring rods to hold springs in place. Remove bolts securing support bracket to cylinder, then remove vertical lever with control levers and support bracket. Remove set screw, then pull pivot shaft from cams and lift cover. Remove control cams with rods and springs. To remove rockshaft and lift cylinder, first remove left-hand lift arm. Slide shaft with right-hand arm out right side of lift cover. Remove bushings and O-rings. Remove rockshaft arm with rod from lift cover. Remove stud nuts securing lift cylinder and remove cylinder from lift housing. Remove piston from cylinder. Inspect all parts for wear, scoring or other damage and renew if necessary. Be sure to renew all O-rings. To reassemble, install cylinder on lift cover and tighten stud nuts nearest front of cover to 197-257 Nm (145-190 ft-lbs.) torque and nuts nearest rear of cover to 278-332 Nm (205-245 ft-lbs.) torque. Stagger piston ring end gaps around piston, then use a suitable ring compressor to assemble piston in cylinder. Install rockshaft in lift cover aligning master spline on shaft with blind splines inside rockshaft arm and lift arms. Reinstall control linkage by reversing the disassembly procedure. Adjust cam pivot shaft to obtain minimum amount of side play in linkage, but cams should move freely without binding.

Draft response dashpot - The draft response dashpot assembly attaches to lever bracket, and can be removed afler removing lifl cover. To disassemble the dashpot, loosen adjusting screw and remove adjustment rod and spring. Invert the housing and remove plunger, needle and spring. Depress piston rod and guide and remove snap ring, then remove spring, piston and spring. Expansion plugs or guide can be removed from body if renewal is indicated. Assemble by reversing the disassembly procedure.

Internal linkage adjustment - The following internal lift linkage adjustments must be performed before reinstalling lift cover. lnvert the lift cover in a fixture or on a bench. Block up the cover as necessary so rockshaft can be moved to the normal raised TRANSPORT position. Check and adjust master control spring. Make sure draft control rod does not contact spring plunger when adjusting master control spring. Move draft control lever to fully lowered position on quadrant and, if necessary, place a wedge between lift cover casting and draft control rod adjusting screw.

Drafl control rod - To adjust drafl control rod, first move drafl control lever to full UP position. Then, adjust control rod cap screw until clearance between cap screw and lift cover casting is 4.1-4.5 mm (0.160-0.180 inch).

Draft control linkage - To adjust draft control linkage, first check for correct initial setting of transport stop as follows: On Massey Ferguson 230, 235, 240, 245, 250 tractors without pressure control, make sure that center of rear bolt holding transport stop plate is 11 mm (7 /16 inch) from rear of slot in quadrant. On MF 230, 235, 240, 245, 250 models with pressure control, be sure that transport stop is positioned at rear of quadrant slot. Move inner quadrant lever against transport stop, then loosen quadrant attaching cap screws and center both quadrants in the mounting slots. Tighten quadrant attaching screws. Move draft control lever between the two sector marks on the draft quadrant. On pressure control models, disconnect pressure control lever from pressure control valve and rear pivot pin, and remove control lever. Remove pressure control adjusting tube with rod, clevis and spring from pressure control valve. On all models, install a wedge to hold dashpot plunger in fixed position against vertical lever. Loosen position control adjusting screw just enough to free the position control lever. Attach a spring scale to vertical lever, and apply 1.4 Kg (3 pounds) of pull against lever while checking clearance between lever and dashpot plunger. Turn draft adjusting bolt, if necessary, to provide correct clearance of 0-0.05 mm (0-0.002 inch). Tighten adjusting screw locknut, then recheck clearance to be sure setting is correct.

Position control - To adjust position control linkage, be sure wedge is still in place holding dashpot fixed against vertical lever. Position a spacer block that is 16.15 mm (0.636 inch) thick between lift cover casting and rockshaft arm making sure arm rests against spacer. Move draft control lever to full UP position of quadrant and move position control lever to transport stop. Use spring scale attached to vertical lever to apply 1.4 Kg (3 pounds) pull to lever, then check that clearance between lever and dash pot plunger is 0-0.05 mm (0-0.002 inch). Turn position adjusting screw, if necessary, to set correct clearance. Tighten adjusting screw jam nut, then recheck clearance.

Pressure control valve - On models equipped with pressure control, reinstall spring and adjusting tube into pressure control valve. Attach pressure control lever to clevis and pivot pin. Move drafl control lever fully UP and move inner quadrant lever to lowest setting within PRESSURE range of quadrant. Hold pressure control lever down securely against actuating cam, then measure distance between bottom of adjusting tube and pressure control valve housing. Turn adjusting tube as required until distance is 31.75-34.93 mm Cl-1/4 to 1-3/8 inches).