MTZ 1220.3 - Page 175

MTZ 1220.1/1220.3 Section J. Possible failures
М7
Defect
,
external
manifestation
Way of elimination
Steering wheel rotates without turn of steerable wheels
Insufficient level of oil in oil tank.
Fill a tank up to demanded level and pump
over hydrosystem for air removal.
Sealings of piston of hydrocyl
inder are worn
out.
Replace sealings or hydrocylinder.
Steering wheel does not rotate to “neutral” position,
“motoring” of pump-meter
Increased friction or shimming in mechani-
cal elements of steering column.
Eliminate reasons of friction and shimming.
Spline shank of steering column and pump-
meter are in
stalled out of axis alignment
(end thrust of cardan shaft) or with insuffi-
cient backlash.
Release cardan.
For in
crease of backlash install additional
wash
ers with thickness no more than 1,5
mm between pump-motor and bracke
t of
steering column.
Increased gap of steering wheel
Conical pins of hydrocylinders or steering
drawbar are not tightened.
Tighten nuts of pins by moment 12...14 ki-
logram-force m and splint.
Increased backlash of spline connection
«cardan of steering shaft — pump-meter».
Replace cardan bottom plug.
Unequal minimum radiuses of turn of tractor to the right
-
to the left
Toe-in is not adjusted.
Adjust toe-in as it is specified in section “Ad-
justments”.
Incomplete corner of turn of directive wheels
In
sufficient pressure in hydrosystem of
steering control.
Adjust pressure within limits 140...155 kilo-
gram-force/sm
2
.
Feeding pump has a defect.
Repair or replace pump.
Hydraulic lift linkage
With hydraulic lift
The unloaded mounted attachment is not lift
ed; when setting any handles of the
distributor to the “lifting” or “lowering” position, no specific sound emitted by the
pump under load
Clogging of the safety valve of the tractor
distributor.
Disassemble and wash the safety valve.
Adjust the pressure main
tained by the
safety valve.
The unloaded mounted attachment is not lifted; when setting any ha
n
dles of the
distributor to the “lifting” or “lowering” position, a specific sound emitted by the
pump under load is heard. After stopping the diesel engine and moving the posi-
tion handle to the foremost position and then to the rear position and starting the
diesel engine, the mounted attachment is lifted (the power handle shall be in the
foremost position).
Clogging the orifice in the overload valve.
Remove the regulator-
distributor from the
tractor, remove a bypass valve from it, wash
the valve and clean off the valve orifice.
The
unloaded
mounted
attachment
is
not
lifted
;
when
setting
any
handles
of
the
distributor to the “lifting” or “lowering” position, a specific sound emitted by the
pump under load is heard. After stopping the diesel engine and moving the posi-
tion handle to the foremost position and then to the rear position and starting the
diesel engine, the mounted attachment is not lifted (the power handle shall be in
the foremost position).