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Massey Ferguson 230, 235, 240, 245, 250 - Brakes and PTO
Brakes
Massey Ferguson 250 and Orchard model tractors, which have planetary
type final drive units in outer ends of rear axle housing, are equipped
with disc type brakes. The disc brakes operate in a dry compartment
within the axle housings on some models, while other models are equipped
with wet type brakes. All other models are equipped with internal
expanding shoe type brakes located at the axle wheel ends.
Shoe-type brakes adjustment - Raise and block rear of MF 250 tractor so
rear wheels are off the ground. Remove adjustmg cover and, using a
screwdriver or adjusting tool, turn star wheels until shoes contact
brake drum. Back off star wheels an equal amount until drums are free
and brake pedal free travel is 25 mm (1 inch) measured at pedal pad.
Latch brake pedals together, then check for uneven brake application. If
necessary, loosen brake adjuster on side that is tight until brakes
apply evenly. Overhaul - The brake drum can be removed after removing
the rear wheel and the two drum retaining screws. Remove shoe retaining
pins and springs, anchor springs and brace. Lift off shoes with adjuster
and spring. Remove brake camshaft, disconnect brake rod and loosen set
screw in brake lever. Withdraw camshaft from brake lever and backing
plate. To reassemble, reverse the disassembly procedure. Adjust brake
rod length so camshaft contacts, but does not move brake shoes with
pedal fully up against its stop. Adjust brake shoes.
Disc-type brakes adjustment - To adjust disc brakes, first make sure
both brake rods are adjusted to equal lengths. Raise and support rear of
Massey Ferguson 250 tractor so rear wheels are off the ground. Turn
brake adjustmg nut at each brake lever until brake pedal free play is
63.5 mm (2-1/2 inches) measured at pedal pad. Latch brake pedals
together and road test to check for uneven brake application. If brakes
pull to one side, equalize braking action by turning brake lever
adjusting nut counterclockwise on side that pulls.
Overhaul - Remove disc brake assemblies, first remove complete axle
housing assembly. Remove brake actuator assembly from left-hand side,
and remove actuator assembly with differential lock mechanism from
right-hand side. Remove retaining screws and withdraw differential
carrier plate. Remove brake components from axle housing keeping parts
in order to ensure correct reassembly. If brake parts and compartment
are coated with oil on models equipped with dry brakes, make certain
that necessary oil seals are renewed before reassembling brakes. Unhook
springs and examine actuator unit and balls for wear or pitting. Groove
depth in wet type friction discs is approximately 0.3 mm (0.012 inch)
when new. Friction discs should be renewed when worn to the point that
grooves begin to disappear. The intermediate plates should be renewed
whenever friction discs are renewed. To reassemble brakes, reverse the
removal procedure while noting the following special instructions: On
wet type brakes, dip friction discs, intermediate plates and actuator
unit in clean transmission oil prior to reassembly. Two friction discs
and one separator plate are installed on planetary side of brake
actuator unit and remaining discs and plates are installed on
differential side of actuator. Be sure that lip of rubber boot is seated
correctly in groove of actuator rod and that garter spring is in proper
position. Adjust brakes.
Power take-off (live)
Output shaft - To remove pto output shaft, first drain oil from
differential housing. Remove pto shield and retainer plate from rear of
housing. Withdraw shaft, rear bearing and seal housing as an assembly.
Oil seal and rear bearing can be renewed at this time. Output shaft
front needle bearing can be renewed after first removing differential
assembly. Remove bearing rearward, then use appropriate size step plate
and driver to install new bearing flush to slightly below rear face of
housing bore. To reinstall output shaft, reverse the removal procedure.
Be sure to lubricate oil seal and O-ring during assembly.
Ground speed gears - Remove ground speed drive gear, driven gear and
bushing, first remove pto output shaft. Remove hydraulic lift cover,
remove hydraulic pump. Remove retaining snap ring and slide drive gear
off bevel pinion shaft. Remove pto shift cover, then slide driven gear
forward out of bushing. To renew driven gear bushing, remove
differential assembly. Drive bushing forward from housing bore. Install
new bushing so front face of bushing is flush with inner end of chamfer
in housing bore. Reinstall gears, reverse the removal procedure.
PTO main drive gears - The pto main drive gears and clutch are included
in Massey Ferguson 230, 235, 240, 245 transmission drive train. Refer to
appropriate transmission and clutch sections for removal and overhaul.
Independent power take-off
Operation - MF 230, 235, 240, 245 tractors may be equipped with an
independent pto which is driven by a flywheel mounted "Split torque"
clutch and controlled by a hydraulically actuated multiple disc clutch
contained in differential housing. The pto front drive shaft is splined
into hub of the "Split torque" clutch cover and turns continuously when
engine is running. The pto control lever is mounted on left-hand side of
cover of differential housing. Moving lever forward disengages the
hydraulically actuated multiple disc clutch and engages the pto brake.
Moving lever rearward releases the hydraulic brake and engages the
multiple disc pto clutch. Hydraulic pressure to actuate the pto clutch
and brake is produced by the auxiliary gear type pump which also
provides power for the Multi-Power clutch and/or auxiliary hydraulic
system if tractor is so equipped.
Output shaft
Remove and reinstall - Remove output shaft, first drain oil from
differential housing. Remove shield and retainer plate from rear of
housing. Withdraw shaft, rear bearing and seal assembly rearward from
housing. Inspect all parts and renew as necessary. Renewal of front
needle bearing requires splitting tractor and removing pto clutch
assembly. Reinstall, reverse the removal procedure. Lubricate oil seal
lip and O-ring before installing.
PTO clutch unit
Remove and reinstall - Remove the pto clutch and valve assembly, first
split Massey Ferguson 230, 235, 240, 245 tractor between transmission
housing and differential housing and remove hydraulic pump assembly.
Withdraw clutch unit from differential housing. Reinstall by reversing
the removal procedure.
Overhaul - Disassemble the 4 removed clutch and valve unit, proceed as
follows: Remove snap ring and thrust washer, then withdraw control valve
housing with brake cylinder from clutch housing. Brake disc is retained
to clutch housing by two pins. Unbolt and remove brake cylinder, piston
and wear plate from valve housing. Remove snap rmg, retainer plate,
friction plates, wave springs and drive plates. Lift out drive hub.
Remove piston and seal rings. Withdraw control valve spool assembly from
housing. Unseat internal snap ring to separate valve spool from plunger.
Note that spacer ball is available in different diameters and is used to
establish collapsed length of control valve assembly. Recommended valve
length is 102.36-103.12 mm (4.030-4.060 inches). Renew clutch plates and
discs if they are excessively worn, distorted or show signs of
overheating. Measure free height of wave springs with springs laying on
a nat surface. All springs should be the same height within 0.5 mm
(0.020 inch). New friction discs should be soaked In clean
transmission/hydraulic oil for 30 minutes before Installation. To
reassemble, install piston with new seal rings into housing. As an aid
in installing piston, three or four pieces of 4 mm (3/16 inch) diameter
rod can be inserted into clutch housing to serve as alignment guides for
piston. Place drive hub in housing, then alternately install drive
plates, wave springs and friction discs making sure that a drive plate
is installed first against piston. Push down on clutch pack to compress
wave springs, then insert two small diameter pins into clutch housing
oil boles to hold clutch pack partially compressed. Install retaining
plate and snap ring, then remove the assembly pins from clutch housing
oil holes. Install seal rings on clutch housing and lubricate with
hydraulic oil. Install valve housing, thrust washer and snap ring.
Assemble brake piston, spring and cylinder. Position wear plate under
brake disc, then install brake cylinder assembly using a new O-ring.
Pressure testing - Power for the independent pto clutch and brake is
supplied by the gear type auxiliary pump which also supplies the
Multi-Power transmission clutch and/or auxiliary hydraulic system if so
equipped. To check pto clutch pressure, first operate tractor until
hydraulic oil temperature is 50-60C (120-140F). Remove pressure test
port plug from pto shift cover and install a 4000 kPa (600 psi) pressure
gage in test port. Start engine and run at 1800 rpm, then move control
lever to engaged (rear) position. Pressure gage reading should be
1900-2240 kPa (275-325 psi). Move pto shift lever to disengaged
position. Pressure should drop to zero and pto shaft should stop
rotating in about five seconds. If pressure or pto operation is not as
specified, remove and overhaul pto control valve unit.
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