
P
aragraphs
1 84-1 86
'Ib
check pto clutch pressure, first
operate tractor until hydraulic oil
temperature is 50�60°C (120�140°F).
Remove pressure test port plug from pto
shift cover and install a 4000
kPa
(600
psi) pressure gage in test port as shown
in Fig. 173. Start engine and run at 1800
rpm, then move control lever to engaged
(rear) position. Pressure gage reading
Fig. 172-Exploded view of
lpto clutch pressure regu·
laUng valve and associated
parts. Muiii-Power shift con·
trol valve (If so equipped) Is
also located In the valve
body.
1
Input
shaft
retamer
2 Gasket
3.
Presaure II ne
4.
Fitting
5. ··o
..
ring
6
. ..
0
.
.
ring
7.
Multi.
Power shot\
valve
8
Valve body
9.
Pressure
reguleting valve
10.
Spring
11. Gasket
12
Plug
13.
Detent
asay
.
Fig. 173-Connecl pressure
gage to test
port
In lpto shift
cover as shown to check
regulating valve pressure.
should be 1900-2240
kPa
(275-325 psi).
Move pto shift lever to disengaged posi·
tion. 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 con
trol valve unit as outlined in paragraph
181.
HYDRAU L I C SYSTEM
GENERAL
All Models
184. Two different types of hydraulic
s
ystems have been used, and identifies·
tion of the type of system must be
established before proceeding with ad
justments or repairs. One type of system
has a dasbpot (1-Fig. 174) attached to
the lift. cover, and lift cover has casting
number 1861 320 Ml. The other type of
s
ystem does not use a dasbpot (refer to
Fig. 174A). Either system may or may
not have provisions for pressure control.
On all 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
72
single acting hydraulic cylinder which
actuates the rockshaft and lift arms. A
gear type auxiliary pump is optionally
added
to
supply operating fluid
to
Multi
Power clutches, ipto clutches and/or aux
iliary 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
All Models
185. The transmission/differential
lubricant is the operating fluid for the
hydraulic system. Recommended fluid is
Massey-Ferguson Permatran
III
Oil.
MASSEY -FERGUSON
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
(Fig. 175), should be removed and
cleaned after every 500 hours of opera
tion. Note that oil must be drained from
housing before removing filter. Filter ele
ment 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.
TROUBLE-SHOOTING
All Models
186. The following are symptoms
which may occur during operation of the
hydraulic lift system and their possible
causes. Use this information in cof\iunc·
tion with the Checks and Adjustments
information to isolate the cause of the
problem before proceeding with compo
nent disassembly.
1. Hitch will not raise. Could be caused
by:
a. Leak in system. Remove response
control side cover and check for in
ternal leakage.
b. Damaged, binding or misadjusted
control valve linkage.
c.
Misadjusted or faulty servo valve
(pressure control units), or faulty
safety relief valve (nonpressure
control units).
d. Faulty bitch lift pump.
2. Lift links raise unevenly or jerky.
Could be caused by:
a. Valve sticking in pump valve
chamber.
3. Lift links will not raise to full height.
Could be caused by:
a. Transport stop misadjusted.
b. Control valve misadjusted.
c.
Control linkage misadjusted.
4. Lift links will not lower. Could be
caused by:
a. Control valve sticking.
b. Control valve misadjusted.
c.
Lift arms binding.
5. Hitch lowers too fast with response
control at "SLOW" position. Could be
caused by:
a
.
Response control misadjusted.
b. Conti'Ol linkage binding or
damaged.
c.
Faulty dashpot (if so equipped).
6. Erratic action when operating in
d.rafl.
control. Could be caused by: