Displacement Pump - Graco LineLazer IV 3900 Series Repair Parts List Manual

Removal
1. Flush pump.
2. Relieve pressure, page 7.
3. Fig. 15. Cycle pump piston rod (A) to lowest posi-
tion.
4. Fig. 15. Remove suction tube (34) and hose (100).
100
Fig. 15
Repair
See manual 310643 for pump repair instructions.
Installation
WARNING
If pin works loose, parts could break off due to
force of pumping action. Parts could project
through the air and result in serious injury or prop-
erty damage. Make sure pin and retaining spring
are properly installed.
CAUTION
If the pump locknut loosens during operation, the
threads of the bearing housing will be damaged.
Make sure locknut is properly tightened.
1. Fig. 18. Pull piston rod out 1.5 in. Screw in pump
until holes in bearing cross link and piston rod
align.
Fig. 18

Displacement Pump

A
34
7672C
1.5 in.
7676B
5. Fig. 16. Use screwdriver: push retaining spring up
and push out pin (235).
Fig. 16
6. Fig. 17. Loosen locknut by hitting firmly with a
20 oz (maximum) hammer. Unscrew pump.
Fig. 17
2. Fig. 16. Push pin (235) into hole. Push retaining
spring into groove around connecting rod.
Fig. 19. Screw jam nut down onto pump until nut
stops. Screw pump up into bearing housing until it is
stopped by jam nut. Back off pump and jam nut to
align pump outlet to back. Tighten jam nut by hand,
then tap 1/8 to 1/4 turn with a 20 oz (maximum) ham-
mer to approximately 75 5 ft--lb (102 N¡m).
Fig. 19
Fig. 20. Fill packing nut with Graco TSL until fluid flows
onto the top of seal.
Fig. 20
235
7675B
7673B
7673B
7677B
311020 21