TM 5-3895-379-23
PROPEL AND VIBRATORY VALVE TESTS AND ADJUSTMENTS - CONTINUED
0184 00
HYDRAULIC SERVO NEUTRAL (MECHANICAL CENTER) ADJUSTMENT
NOTE
Charge Pump System Pressure Test must be completed before performing Hydraulic Servo Neutral
Mechanical Center Adjustment.
1.
Place propel control lever in NEUTRAL (TM 5-
22,23
3895-379-10).
NOTE
The following step equalizes oil pressure
on each side of servo piston.
2.
Remove two plugs (22) from ports (23) and connect
jumper hose between two ports (23).
3.
Connect two 9000 psi (60,000 kPa) pressure gauges
to pressure taps (8) and (9).
4.
Move propel control lever to LOW SPEED range
(TM 5-3895-379-10).
5.
Start and run the engine at 1500 rpm (TM 5-3895-
379-10).
401-2150
NOTE
Pressure gauge readings should be the same.
6.
If readings are not the same, adjust neutral position (mechanical center) of the piston (27) as follows:
a.
Loosen locknut (24) on piston rod adjustment screw (25).
b.
Turn piston rod adjustment screw (25) clockwise or counterclockwise depending on spool movement require-
ment.
c. Adjust piston rod adjustment screw (25) until pressure readings are same.
7.
Stop engine (TM 5-3895-379-10).
8.
Remove two 9000 psi (60,000 kPa) gauges and install two 600 psi (4000 kPa) gauges on ports (23).
9.
Repeat steps 5 through 7.
10.
Tighten locknut (24).
11.
Remove pressure gauges from pressure taps (8) and (9).
12.
Remove jumper hose from two ports (23).
13.
Install plugs (20) on ports (23).
25
24
401-2151
0184 00-5
