TM 5-3820-241-34
CHAPTER 4
MAINTENANCE OF AIR SYSTEM COMPONENTS
Section I. AIR MOTOR (Hydraulic Pump Drive Motor)
4-1. General
This section covers repair instructions for the air
motor. The air drive motor is a pressure
regulated, vane type motor used to drive the
hydraulic system. Pressure is regulated at 65 psi,
by a spring type control that regulates the
amount of air to the pump drive motor.
4-2. Air Motor Removal and Disassembly
a. Removal. Refer to TM 5-3820-241-12 and
remove the air motor.
b. Disassembly. Disassemble the air motor in
numerical sequence as illustrated in figure 4-1.
1 Hex head capscrew
7 Forward flange
13 Rotor vane spring
19
2 Exhaust elbow
Locator pin
8 Forward flange oil seal
14 Rotor shuttle pin
20 Oil seal
3 Exhaust nipple
9 Ball bearing
15 Rotor stator
21 Ball bearing
4 Exhaust elbow
10 End plate
16 Socket head capscrew
22 End plate
5 Hex head capscrew
11 Rotor assembly
17 Lockwasher
23 Motor housing
6 Lockwasher
12 Rotor vane
18 Rear flange
24 Housing set screw
Figure 4-1. Air motor, disassembly and reassembly.
4-3. Air Motor Cleaning, Inspection and Repair
a. Cleaning.
(1) Wash all parts with cleaning solvent (Fed
Spec PD 680) and dry thoroughly.
(2) Discard and replace oil seals.
b. Inspection and Repair.
(1) Inspect the rotor bearings for excessive
wear, rough spots or binding. Replace defective
bearings.
(2) Inspect the rotor vanes for chips and
excessive wear. If any vane is defective, replace
them all with a rotor vane kit.
(3) Inspect the rotor and rotor stator for
cracks, scores and rough spots. Remove minor
rough spots with a fine emery cloth. Replace a
defective rotor or stator.
(4) Inspect the motor housing, forward
flange, rear flange, and end plates for cracks,
4-1
