15
307982
Displacement Pump Service
10. Remove the packing nut (114) from the piston rod
(122). Remove the packings and female gland
from the intake cylinder’s packing housing (Ref.
117).
11. Unscrew the piston valve (112) from the piston
valve housing (110), taking care not to drop the
piston ball (132).
12. Remove the packings and glands from the piston.
13. Remove the cylinder (111) and o--rings (125). If the
cylinder cannot be removed easily, contact your
Graco distributor for assistance.
14. Inspect the outer surface of the displacement rod
(108) and the inner surface of the pump cylinder
(111) for scoring and wear by holding them up to a
light or running a finger over the surface. Replace
these parts, if necessary. If the rod is worn, the
packings will not seal properly and the pump will
leak. If the cylinder is worn, the pump will not stall
against pressure.
15. Clean all parts in a compatible solvent, inspect
them, and replace as necessary.
Reassembly
1. Place an o--ring (125
{
) on the packing nut (140).
Screw the packing nut into the pump housing
(109).
NOTE:
Lubricate the parts with a compatible lubricant
before assembling.
2. Refer to Fig. 5. The gland/packing stack (159
{
) for
the throat is preassembled. Do not disassemble
the stack. Place the gland/packing stack into the
packing nut (140). Be sure the lips of the v--pack-
ings are facing down.
Fig. 5
Throat Packings
All Models
Note:
Lips of v--packings must face down.
136
140
{
125
159
{
Throat Gland/
Packing Stack
