819.0254
15
Service
Repairing the Air Valve
Tools Required
•
Torque wrench
•
Torx (T20) screwdriver or 7 mm socket wrench
•
Needle-nose pliers
•
O-ring pick
•
Lithium base grease
NOTE: Air Valve Repair Kit 819.4274 is available. Refer
to page 24. Parts included in the kit are marked with a
symbol, for example (10†). Use all the parts in the kit for
the best results.
Disassembly
1.
Relieve the pressure.
2.
With a Torx (T20) screwdriver or 7 mm (9/32 in.)
socket wrench, remove the six screws (8), air valve
cover (7), and gasket (10). See Fig. 7.
3.
Move the valve carriage (11) to the center position
and pull it out of the cavity. Remove the valve block
(13) and o-ring (12) from the carriage. Using a
needle-nose pliers, pull the pilot block (9) straight up
and out of the cavity. See Fig. 8.
4.
Pull the two actuator pistons (30) out of the bearings
(31). Remove the u-cup packings (22) from the
pistons. Pull the push pins (26) out of the bearings
(28). Remove the o-rings (27) from the push pins. See
Fig. 9.
5.
Inspect the valve plate (14) in place. If damaged, use
a Torx (T20) screwdriver or 7 mm (9/32 in.) socket
wrench to remove the three screws (8). Remove the
valve plate (14) and seal (15). See Fig. 10.
6.
Inspect the bearings (28, 31) 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.
Replace as needed. Reassemble as explained on
page 16.
Fig. 7
Fig. 8
WARNING
To reduce the risk of serious injury whenever you are
instructed to relieve pressure, always follow the
Pressure Relief Procedure on page 11.
Torque to 50–60 in-lb
(5.6–6.8 N•m).
2
See Detail at right.
Grease.
Grease lower face.
1
2
3
