TESTING AND ADJUSTING
The unloader valve stem and spring are removed for
To remove check valve (19), spring (22), and retainer
cleaning or repair after the plug for the spring and the
(20), disconnect the oil line from the combination valve to
lever are removed from the valve body. If the lever does
the steering system and remove fitting (21).
not move easily in the housing, the boot, the nut, the
MOTOR FOR CIRCLE DRIVE
screw and the bearings must be taken apart and
The motor for the circle drive (I) that turns the circle, is
cleaned. The lever must have .006 + .003 in. (0.15 +
an axial piston motor and is like the variable
0.08 mm) of end clearance after the lever and housing
are installed on the valve body.
MOTOR FOR CIRCLE DRIVE
COMBINATION VALVE PARTS
1. Circle drive group. 2. Cover of motor. 3. Line for oil
(With no unloader valve)
leakage from the motor.
2. Plug for pressure reduction valve. 3. Plug for relief
valve. 4. Shims. 5. Spring. 6. Pilot valve. 7. Spring.
The lines for the pump oil to the motor are
8. Valve. 9. Spacer. 10. Plug. 11. Retainer. 12.
connected to the cover (2) of the motor. Oil leakage
Spacer. 13. Spring. 14. Stop. 15. Washer and shims.
from the motor goes through line (3) also connected to
16. Stem. 17. Piston. 18. Plug. 19. Check valve. 20.
the cover of the motor. When the motor is running, there
Retainer. 21. Fitting. 22. Spring for check valve.
is a variable amount of oil leakage through line (3).
Remove plug (3), retainer (11) and pilot valve (6).
There is very little oil leakage from the motor when
Shims (4) are under spring (5) in retainer (1 ). Add shims
the oil is cool and there is only a small load for the motor
for an increase, or remove shims to get a decrease in
to turn. Oil leakage through line (3) can be 2 U.S. gpm
the pressure setting of the relief valve. The pressure
(7.6 litre/min) when the oil is hot and the motor is turning
setting of the relief valve is 3900 + 100 psi (274.2 7.0
a large load.
kg/cm2), with an oil flow of 2.5 .2 U.S. gpm (9.5 + 0.8
litre/min). If it is necessary to make an inspection and
When there is too much oil leakage through line (3),
clean the other parts of the relief valve, remove plug
the motor runs slow and does not have very much
(10), spacer (12), spacer (9), valve (8) and spring (7).
The seat and body for pilot valve (6) and valve (8) must
be pushed out the opening for plug (10).
If line (3) is disconnected to make a test for the
amount of oil leakage from the motor, always install a
When it is necessary to make an inspection and
plug or cap where the oil line was disconnected. When
clean the pressure reduction valve parts, remove plug
the engine is running, the plug or cap keeps air from
(2), spring (13), stop (14) and washer and shims (15).-
going to the pump for the oil cooler system.
Add shims for an increase, or remove shims for a
decrease in the pressure reduction of the oil to the
A control valve is on each side of the steering wheel
below the floor plates. Each of the two control valves
The pressure reduction setting for the valve is 1375
can have either four, five or six valve sections, between
+ 25 psi (96.7 + 1.8 kg/cm2) when-the pressure of the
the inlet and outlet manifold and the end manifold. The
oil in the combination valve is 3500 + 100 psi (246.1
parts (valves, springs, spacers and shims) can be
7.0 kg/cm2), and the flow of oil into the combination
removed for cleaning or for
valve is 17 + I U.S. gpm (64.3 + 3.9 litre/min).