TRAVEL MOTOR.

surface smoothness to less than 33 micro-inches. This

(3) Install bearing (10) in top end of plunger

finish may be obtained, after lathe turning, with a

(28). Install bearing (15) in primary cylinder (21). Install

commutator stone.

guide (26) and retaining ring (27).

(4) Install cylinder (22) with assembled items

(3) Check brush length of used brushes by

through bottom of primary plunger (28) and install both

comparing them with new brush. If brushes have less

in primary cylinder (21).

than one-half length of new brushes, replace them, as

(5) lnstall new packing (14) and retainer (13).

they probably will not last until next disassembly.

Put wiper ring (1 2) in packing nut ( 1) and install

(4) Inspect bearings. Replace if necessary.

packing nut in end of primary cylinder (21).

(6) Place packing (9) over plunger (29) and

6-205. ASSEMBLY. Reverse procedures in paragraph

install packing retainer (8). Put wiper ring (7) in packing

6-202.

nut (6); lnstall nut over plunger (29) and thread into

6-206. TEST. Test as follows:

plunger (28). Install two new washers (2) and replace

(1) Excite the field with rated current and

screws (1).

voltage.

(2) Seat the brushes, and run the motor with

6-201. TRAVEL MOTOR.

low (6 or 12 volts DC) voltage on the armature

6-202. DISASSEMBLY. Clean exterior thoroughly, then

terminals. Armature must now turn clockwise, viewed

disassemble only as far as necessary to repair, as

from commutator end.

follows:

(3) After brushes have been seated and

(1) Remove screws (5 1 and 54, figure 7-36)

motor has run for four minutes, check bearing housings

washers and nuts, and take off covers (50).

for head caused by motor yoke misalignment or bad

(2) Disconnect leads (37 and 38) at brush

bearings.

Observe commutator and brushes for

holders (43). Remove brushes (42) from motor.

sparking at this time.

(3) Remove screws (28) and washers (29).

(4) Make a high potential test above ground

Take off rear motor yoke (27). Remove screws (23),

on all windings, using a 115 volt AC test light.

washers (24), bearing retainer (22), washer (25) and

bearing (26).

6-207. HYDRAULIC PUMP MOTOR.

(4) Remove socket head screws inside brush

6-208.

DISASSEMBLY.

Clean motor exterior

inspection holes, which attach front motor yoke (49) to

thoroughly with solvent, and disassemble as follows:

motor ring (7 1) and separate ring, armature (59) and

(1) Remove both covers (4, figure 7-15),

yoke (49). Take nut (60), washers (36, 61 and 62),

remove screws (13) and washers, and take brushes (12)

insulator (35) and leads (37-38) from yoke.

from motor.

(5) Remove screws (70) to free pole pieces

(2) Remove screws (9) and take grease cap

(69), insulators and field coils (66).

(8), retaining ring (11) and bearing (10) from end bell

(39).

6-203. CLEANING. Clean parts as follows:

(3) Remove screws (40) and take front end

(1) Remove as much dirt as practical from

bell (39) from motor housing (53).

parts with compressed air.

(4) Remove nuts (23), washers (24 and 25),

(2) Wipe remaining dirt from parts with a

studs (28) and connectors (34 and 35), and insulators

cloth slightly moistened with solvent. Do not wet

(27, 36, 22 and 38).

armature or field windings.

NOTE

(3) Clean commutators to bright finish with a

commutator stone. Do not use emery cloth.

Tag wires to insure correct assembly and proper

rotation of motor.

6-204.

INSPECTION AND REPAIR.

Proceed as

(5) Remove brush holders (16) and insulators

follows:

(21 and 20).

(1) If balancing machine is available, check

(6) Remove screws (43) and retaining ring

that armature dynamic balance is within 1 inch- ounce,

(46). Separate end bell (42) from motor housing (53). If

at 3000 revolutions per minute.

bearing (45) remained in bell housing, remove.

(2) Measure commutator runout. If in excess

(7) Remove armature (47) from motor

of 0.002 inch total indicator reading, turn in lathe, truing

housing. Pull bearing from shaft if necessary.

commutator within above limits, and holding copper

6-46