17
307982
Displacement Pump Service
6. Install the piston ball (132) in the piston valve
housing (110). Apply medium grade thread sealant
to the threads of the piston valve (112) and hous-
ing (110). Screw the piston valve into the piston
valve housing, torquing to 81--102 N
S
m (60--76
ft-lb). Screw the piston rod (122) into the piston
valve, aligning the holes. Insert the cotter pin
(126
{
).
7. Place the pump housing (109) in the vise. Install
the new o--rings (125
{
) on the pump cylinder (111).
Lubricate the cylinder and slide it into the pump
housing as far as possible.
8. Slide the rod guide (113) onto the piston rod (122),
with the flat side facing down.
9. Install the displacement rod assembly through the
bottom of the pump, guiding it carefully through the
throat packings.
10. Refer to Fig. 7. The gland/packing stack (158
{
) for
the intake valve is preassembled. Do not disas-
semble the stack. Install the gland/packing stack in
the intake cylinder’s packing housing (Ref. 117).
Be sure the lips of the v--packings are facing up.
Install the packing nut (114
{
) and torque to 34--47
N
S
m (25--35 ft-lb). Slide the assembly, packing nut
first, onto the piston rod (122).
Fig. 7
122
Ref. 117
114
{
158
{
Intake
Valve
Gland/
Packing
Stack
11. Place an o--ring (124
{
) around the intake cylinder
(117). Screw the cylinder into the pump housing
(109). Torque to 129--149 N
S
m (94--110 ft-lb).
12. Thread the nut (120) onto the bottom of the piston
rod. Install the valve plate (118), valve guide (121),
priming piston (119), and the other nut (120).
13. Holding both nuts (120) with a wrench, torque the
bottom nut to 54--81 N
S
m (40--60 ft-lb).
14. Tighten the packing nut (140). Torque the wet--cup
nut to 54--81 N
S
m (40--60 ft-lb).
15. Reconnect the displacement pump (14) to the air
motor (15). Refill the wet--cup (136) with TSL.
Reconnect the ground wire to the air motor if it
was disconnected during service.
