Graymills DDP 1' Pump OMI - Manual (Page 15)

15
Service
Repairing the Air Valve
Tools Required
D Torque wrench
D Torx screwdriver or 8 mm (or 5/16”) socket wrench
D Needle-nose pliers
D O-ring pick
D Lithium base grease
NOTE: Air Valve Repair Kit 784–90616 is available.
Disassembly
WARNING
To reduce the risk of serious injury whenever you are
instructed to relieve pressure, always follow the Pres-
sure Relief Procedure on page 11.
1. Relieve the pressure.
2. With a torx screwdriver or 8 mm (or 5/16”) socket
wrench, remove the six screws (3), air valve cover (2),
and gasket (4). See Fig. 7.
3. Move the valve carriage (5) to the center position and
pull it out of the cavity. Remove the valve block (7)
and o-ring (6) from the carriage. Using a needle-nose
pliers, pull the pilot block (18) straight up and out of
the cavity. See Fig. 8.
4. Pull the two actuator pistons (11) out of the bearings
(12). Remove the u-cup packings (10) from the pistons.
Pull the pilot pins (16) out of the bearings (15). Re-
move the o-rings (17) from the pilot pins. See Fig. 9.
5. Inspect the valve plate (8) in place. If damaged, use a
torx screwdriver or 8 mm (or 5/16”) socket wrench to
remove the three screws (3). Remove the valve plate
(8) and seal (9). See Fig. 10.
6. Inspect the bearings (12, 15) in place. See Fig. 9. The
bearings are tapered and, if damaged, must be removed
from the outside. This requires disassembly of the fluid
section. See page 21.
7. Clean all parts and inspect for wear or damage. Re-
place as needed. Reassemble as explained on page 16.
Torque to 28 to 33 in-lb
(3.2 to 3.7 N-m).
Figure 7 3
2
4 {
2
2
04164A
04165
{18
5
Figure 8
1
2
See Detail at right.
Grease.
3
Grease lower face.
1
{7
{6
5
2
3
3
11
16