Section XVI. REPAIR OF PUMP AND MASTER SWITCH RELAYS

TM 10-3930-609-35

3-109. Cleaning Disassembled Parts of Directional -

d. Replace terminal boards and contact fingers if

Control Switch

contact points are pitted or burned.

a. Blow dust from parts with compressed air under

moderate pressure.

3-112.

Reassembly of Directional Control Switch

(fig. 3-21)

b. If additional cleaning is required, wash parts in

a. Position trip lever in housing, install trip shaft

SD and dry with compressed air.

and secure with flatwasher, lockwasher and nut.

3-110. Inspection of Directional Control Switch

b. Insert shaft through side of housing, then

Parts

through bushing and carrier. Secure carrier to shaft with

screw, lockwasher and fiatwasher.

a. Inspect threaded parts and tapped holes for

stripped threads or other thread damage.

c. Insert pins through arms; then, place arms in

housing and secure with clips and screws.

b. Inspect cover, housing, lever, arms, clips,

carrier, contact fingers and terminal boards for cracks,

d. Hook ends of springs to studs in arms. Rotate

distortion, corrosion or other damage.

shaft and check for proper detent action.

c. Inspect contacts on terminal boards and on

e. Install terminal boards in housing with screws.

contact fingers for pitting, burning or other damage.

f. With spring inserted between contact fingers,

d. Inspect springs for excessive stretch.

squeeze fingers together and insert in carrier; then,

rotate fingers 1/4 turn to lock, in carrier.

3-111. Repair and Replacement of Directional

g. Secure cover to housing with screws and

Control Switch Parts

washers and attach lever to shaft with screw and

a. Repair minor thread damage with a tap or

lockwasher.

thread chaser.

b. Replace all cracked, distorted or corroded parts.

c. Replace springs if damaged in any way.

Section XVI. REPAIR OF PUMP AND MASTER SWITCH RELAYS

3-113.

Description of Pump and Master Switch

c. Remove screws securing guide to armature and

Relays

screws securing support to frame assembly and

Two single pole relays of similar design are used in the

withdraw these parts.

electrical control system. Each relay has a single

d. Remove retaining ring, cup washers and spring

normally open set of contacts. One contact of the set is

from pin, and separate pin and contact support from

mounted on the relay armature which is spring loaded in

armature.

the open position. The other contact is mounted on a

e. Remove self-locking nuts and lockwashers from

fixed contact support.

threaded studs on contacts and remove contacts from

both contact supports.

3-114. Removal of Pump and Master Switch Relays

f. Remove screws and flatwashers which secure

Removal of the pump and master switch relays from the

U-shaped contact support to base and withdraw contact

control panel is required for repair as described in the

support and shims.

following instructions. Refer to paragraph 226 or 227 as

g. Remove screws and flatwashers from posts;

appropriate for removal procedures.

then, unscrew posts from frame assembly and remove

spacers.

3-115.

Disassembly of Pump and Master Switch

h. Remove retaining ring from frame assembly

Relays (fig. 3-22)

and lift coil and spring washer from frame assembly.

a. Remove capscrew and lockwasher at each end

i. To separate frame assembly from base, take

of shunt and withdraw shunt and terminal from contact

out screws and flatwashers which secure frame

support and terminal from contact support and frame

assembly to base.

assembly.

b. Remove self-locking nut, cup washer and spring

from screw extending through fulcrum, guide and

support; then, remove screw and fulcrum.

3-39