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

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

Main hydraulic pump

Remove and reinstall - To remove the main hydraulic pump on Massey Ferguson 230, 235, 240, 245 tractors not equipped with independent pto, Multi-Power and/or auxiliary hydraulics, first drain hydraulic oil. Remove lift cover. Remove the adjusting block and upper tube and spring from servo valve. Collapse and remove the drive shaft coupler and remove pto output shaft. Remove dowel pins from each side of differential housing, then lift hydraulic pump out through top opening of housing. On MF 230, 235, 240, 245 tractors equipped with independent pto, MultiPower and/or auxiliary hydraulics, tractor must be split between differential housing and transmission. Drain oil from system and remove lift cover. Remove step plates and disconnect brake tods and electrical wiring as necessary. Disconnect pressure line at Multi-Power/independent pto pump if so equipped. Support transmission housing and differential separately, remove retaining bolts and separate rear of tractor from transmission housing. Remove pump mounting dowels from each side of differential housing. Disconnect hydraulic pipes from the pumps and remove tube and spring from pump servo valve. Slide pump assembly forward through front opening of differential housing. The gear train mounting plates serve as pump support. Idler gear contains 22 loose needle bearings. Gear backlash is not adjustable; renew parts as necessary if backlash exceeds 0.38 mm (0.015 inch) between any two gears. To reinstall pump assembly, reverse the removal procedure.

Overhaul - To disassemble the removed hydraulic pump, first separate the auxiliary pump and drive train from main pump. Turn pressure control adjusting screw out of pivot lever until end of bolt is flush with inside of lever. Remove adjusting block, tube and spring from servo valve if not removed previously. Unhook diaphragm lever link from control valve, remove valve mounting stud nut, and remove servo valve from top of pump. Remove clip retaining control lever, then slide control lever from control valve. Remove rollers and pin from end of control valve actuating rod. Remove filter assembly and intake housing from pump. Remove retainer clip and cap from front of oscillator drive. Remove pin retaining oscillator to cam follower. Remove nuts attaching pump bodies together, then carefully remove front body. Withdraw control valve and oscillator as a unit from pump. Carefully slide piston yokes, valve chambers, cam blocks and camshaft away from rear body. Pull valve spool sleeve from rear body.

Servo valve - Thread a suitable screw into retainer plug and remove retainer, spring, discs and secondary relief valve. Remove guide and spring support, then bump housing to remove plunger and ball. Use hooked wire to pull plunger guide from bore then use needlenose pliers to pull ball valve seat from bore. Inspect all parts for wear or damage and renew as necessary. Diameter of large end of plunger should be 5.530-5.542 mm (0.2177-0.2182 inch), and diameter of tapered end of plunger should be 5.080-5.232 mm (0.200-0.206 inch). Bore of plunger guide should be 5.644-5.669 mm (0.2222-0.2232 inch). Maximum diameter of seat in ball valve is 4.32 mm (0.170 inch). All O-rings should be soaked approximately one hour in hydraulic oil before assembling. Install new back-up washer and O-ring on ball valve seat, then install in bore of housing. Install new O-ring on plunger guide, then insert plunger guide into bore with cross drilled hole toward ball valve seat. Insert ball into bore and make sure it enters bore of guide. Install plunger with tapered (small) end toward ball. Install spring support with large flat end against plunger guide. Apply two or three drops of Loctite 242 on threads of spring guide, then install and tighten to 20-40 Nm (15-30 ft-lbs.) torque. Insert secondary relief valve, discs, if so equipped, spring and retainer into bore in bottom of housing. The retainer is a light press fit and should be installed flush with mounting surface of valve body. Install orifice plug, diaphragm, spring, cover, lever and related parts.

Control valve - Massey Ferguson 230, 235, 240, 245 control valve is serviced as a matched assembly which consists of rod and all parts. To disassemble the valve and oscillator assembly, unseat and remove retaining ring from internal groove in oscillator housing and withdraw valve from oscillator unit. Remove retaining ring while compressing spring. Push rod in and remove snap ring, then withdraw remaining parts. Assemble by reversing disassembly procedure. End of valve spool with narrow slot should be toward oscillator rod; end with larger slots should be toward actuating rod. Install sleeve in rear body bore so roll pin is down near bottom. Valve chambers - Both valve chambers are identical and interchangeable, and each contains two sets of valve components. To disassemble the chamber, remove snap ring and thread a 1/4 inch UNC bolt into plug to provide leverage. Plug can be pulled by hand. A resealing reamer is available which dresses both seats in one bore at the same time. If tool is used, remove only enough metal to smooth the seats. All parts are available individually. When installing, do not compress retainer plug deeper than 5.8 mm (0.23 inch) from top of plug to top of valve chamber. Be sure to pull plug up against snap ring after snap ring is seated.

Intake housing - The response control valve and non return valve are contained in the intake housing. When reassembhng, be sure O-ring, washer and retaining ring are correctly installed on cover plate. Install ring on nonreturn valve, then insert valve through bore in housing. Install seal over valve stem followed by retainer, spring, cap and E ring. Install cover plate and gasket onto intake housing. Position intake housing onto rear body making sure roll pin in valve sleeve engages slot in intake housing. Tighten the retaining cap screws to 20-27 Nm (15-20 ft.-lbs.) torque. Assembly - Assemble valve chambers onto piston yokes making sure chamfered corners of yokes face away from each other. Install camshaft, cam follower and cam blocks into piston yokes making sure cam block with shoulder is at front (widest lobe) of camshaft and that shoulder faces inward. Slide camshaft assembly into rear body making sure end of cam follower is towards bottom of pump. Install control valve assembly into rear body, then position front body over camshaft and studs. Tighten stud nuts evenly to 41-47 Nm (30-35 ft-lbs.) torque. Make sure camshaft and pistons move freely. Install cap and retaining ring on end of oscillator housing. Connect cam follower to oscillator.

Auxiliary pump

Two different auxiliary pumps have been used. Single section auxiliary pump is used on MF 230, 235, 240, 245 tractors equipped only with Multi-Power transmission and/or independent pto. Dual section pump is used for auxiliary hydraulic applications as well as for Multi-Power or independent pto pressure. On all models, the auxiliary pump is located directly above the mainhydraulic pump within the differential housing. The auxiliary pump is removed with the main hydraulic pump as a unit.

Single pump

To disassemble the removed pump, first remove snap ring retaining drive gear to pump shaft. Remove cap screws securing pump to gear train mounting plate, then remove pump. Remove cap screws attaching end cover to body and separate pump components. Inspect all parts for wear or damage. All parts except pump body are available for renewal. Pump gears must be renewed as a matched set. To reassemble, reverse the disassembly procedure. Be sure relieved edge of pressure plate is towards outlet side of pump and smooth side is away from gears. Tighten cover retaining cap screws evenly to 27 Nm (20 ft-lbs.) torque. Safety relief valve is set to open at 4480-5170 kPa (750-850 psi). If valve requires servicing, adjust pressure setting as follows: Turn adjusting screw in until it bottoms, then turn screw out 1-1/2 turns. Attach a hand pump with pressure gage to pump outlet port and check valve opening pressure. Turn adjusting screw as necessary, then stake the screw when correct pressure is obtained.

Dual pump

It is recommended that Massey Ferguson 230, 235, 240, 245 auxiliary hydraulic system pressure be checked prior to servicing the hydraulic pump. The pressure can be checked at an auxiliary valve outlet using suitable pressure gage and fittings. System pressure should be between 15860-17925 kPa (2300.2600 psi). Hydraulic lift cover must be removed for access to the adjustable high pressurerelief valve which is located in pump rear cover plate. To disassemble the removed pump, first remove snap ring retaining drive gear to pump shaft. Remove cap screws attaching pump to gear train mounting plate and remove pump from rear plate. Scribe a line across pump bodies and end cover to ensure correct alignment when reassembling. Remove tie bolts attaching pump bodies to end cover, then separate pump components. Use care to avoid damaging machined mating surfaces and gear pockets of pump bodies. Do not remove high pressure adjusting screw; screw is staked in place and setting should not be changed. Check all parts for evidence of wear or damage and renew as necessary. If pump housings show evidence of wear or scoring in gear pocket area, complete pump must be renewed.

To reassemble, reverse the disassembly procedure while noting the following special instructions: Be sure pressure seal is installed into wear plates first, then install back-up gasket. Seal side of wear plates must face away from gear faces. Omit high pressure relief valve spring when assembling pump bodies, and use tie bolts to draw bodies together over dowel pins. Then, remove tie bolts and separate end cover from spacer plate. Install retaining washer and high pressure spring, position end cover on pump and tighten retaining screws and nut to 27 Nm (20 ft-lbs.) torque. If low pressure relief valve was removed from pump body, tighten adjusting screw until spring is bottomed, then back screw out four turns. This should set relief valve opening pressure within specified range of 4480-5515 kPa (650-850 psi). A suitable hand pump with pressure gage can be connected to Multi-Power circuit outlet port to check opening pressure if desired. High pressure relief valve adjustmg screw should not have been turned during disassembly. However, if parts of relief valve were renewed, it will be necessary to readjust valve setting after pump is reinstalled. Hydraulic lift cover must be removed to gain access to relief valve adjusting screw. Maximum system pressure should be 15860-17925 kPa (2300-2600 psi).

Auxiliary valve (MF 230, 235, 240, 245 tractors)

Overhaul - To disassemble valve, remove snap ring and end plug. Loosen detent assembly adjusting screws, then unbolt and remove end cap from valve body. Withdraw spool assembly from spring end of valve body. Valve spools are selective fitted to their body bores and must not be interchanged. When servicing dual spool valve, identify spools as they are removed to ensure correct reassembly. Remove retaining ring, centering spring and spring seats from end of spool. Remove screw, spring, poppet and pin or ball from regulator barrel. Unscrew regulator barrel from spool, then remove roll pin and guide from regulator barrel. Remove switch valve and check valve from valve body. Inspect all parts for wear, scoring or other damage and renew if necessary. Valve spools and body are available only as a complete valve assembly. Be sure to renew all O-rings. To reassemble valve, reverse the disassembly procedure. Adjust spool detent and "kick out" pressure setting.

Adjustment - Connect a suitable flow meter to rear couplers. Operate engine at 1000 rpm and place auxiliary valve control handle in "lift" position. Tighten detent adjusting screw until handle remains in "lift" position. Slowly close flow meter restrictor valve and note pressure at which control handle kicks out of detent and returns to neutral. Handle should kick out of detent when pressure is between 13100-14480 kPa (1900-2100 psi). If handle kicks out before pressure reaches 13100 kPa (1900 psi), shut off engine and operate control valve handle to relieve any trapped pressure. Remove 4 snap ring and end plug, then turn regulator valve adjusting screw inward to increase kick out pressure. Several attempts at adjustment may be necessary before desired kick out pressure Is obtained. Be sure to shut off engine and relieve system pressure before removing end plug from valve. If handle does not kick out of detent when pressure is between 13100-14480 kPa (1900-2100 psi) and a "squealing" noise from control valve is heard, loosen control handle detent screw until handle releases within specified pressure range. If control handle does not kick out of detent. and no "squealing" sound is heard, shut off engine and remove end plug from valve. Turn regulator adjusting screw outward to decrease kick out pressure. Reinstall plug and recheck for proper operation.

Auxiliary valve (Massey Ferguson 250 tractor)

Overhaul - To disassemble auxiliary valve, remove single/double acting convertor valve, check valve and detent relief valve assembly from valve body. Remove end cap. Unscrew retaining screw and remove centering spring, spring seats and end plate. Remove pivot bracket with wiper seal. Pull spool out of valve body and remove detent carrier, piston and cage. Inspect all parts for wear and renew as necessary. Valve spool and body are available only as a matched set. Be sure to renew all O-rings. When reassembling, use petroleum jelly to hold detent balls in place. Clean the threads of retaining screw and valve spool, then apply a drop of thread locking compound to threads of screw before installing. Check and adjust spool detent "kick out" pressure.

Adjustment - To set valve spool detent "kick out" pressure, connect a suitable flow meter to auxiliary valve rear couplers. Operate engine at 1000 rpm and place control valve handle in "lift" position. Slowly close flow meter restrictor valve and note pressure at which control valve kicks out of detent and returns to neutral. Valve should kick out of detent at approximately 16550 kPa (2400 psi). Kick out pressure is adjusted by turning detent relief valve adjusting screw in or out.