16 308479
Service
Repairing the Air Valve
Tools Required
D Torque wrench
D Torx (T20) screwdriver or 7 mm (9/32”) socket
wrench
D Needle-nose pliers
D O-ring pick
D Lithium base grease
NOTE: Air Valve Repair Kit 236273 is available. Refer
to page 25. Parts included in the kit are marked with a
symbol, for example (4{). Use all the parts in the kit for
the best results.
Disassembly
WARNING
To reduce the risk of serious injury whenever you
are instructed to relieve pressure, always follow the
Pressure Relief Procedure on page 11.
1. Relieve the pressure.
2. With a Torx (T20) screwdriver or 7 mm (9/32”)
socket wrench, remove the six screws (3), air
valve cover (2), and gasket (4). See Fig. 8.
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. 9.
4. Pull the two actuator pistons (11) out of the bear-
ings (12). Remove the u-cup packings (10) from
the pistons. Pull the pilot pins (16) out of the
bearings (15). Remove the o-rings (17) from the
push pins. See Fig. 10.
5. Inspect the valve plate (8) in place. If damaged,
use a Torx (T20) screwdriver or 7 mm (9/32”)
socket wrench to remove the three screws (3).
Remove the valve plate (8) and seal (9). See Fig.
11.
6. Inspect the bearings (12, 15) in place. See Fig. 10.
The bearings are tapered and, if damaged, must
be removed from the outside. This requires disas-
sembly of the fluid section. See page 22.
7. Clean all parts and inspect for wear or damage.
Replace as needed. Reassemble as explained on
page 16.
Reassembly
1. If you replaced the bearings (12, 15), reinstall as
explained on page 22. Reassemble the fluid sec-
tion.
2. Install the valve plate seal (9{) into the groove at
the bottom of the valve cavity. The rounded side of
the seal must face down into the groove. See
Fig. 11.
3. Install the valve plate (8) in the cavity. The plate is
reversible, so either side can face up. Install the
three screws (3), using a Torx (T20) screwdriver or
7 mm (9/32”) socket wrench. Tighten until the
screws bottom out on the housing. See Fig. 11.
4. Install an o-ring (17{) on each pilot pin (16).
Grease the pins and o-rings. Insert the pins into
the bearings (15), narrow end first. See Fig. 10.
5. Install a u-cup packing (10{) on each actuator
piston (11), so the lips of the packings face the
narrow end of the pistons. See Fig. 10.
6. Lubricate the u-cup packings (10{) and actuator
pistons (11). Insert the actuator pistons in the
bearings (12), wide end first. Leave the narrow
end of the pistons exposed. See Fig. 10.
7. Grease the lower face of the pilot block (18{) and
install so its tabs snap into the grooves on the
ends of the pilot pins (16). See Fig. 9.
8. Grease the o-ring (6{) and install it in the valve
block (7{). Push the block onto the valve carriage
(5). Grease the lower face of the valve block. See
Fig. 9.
9. Install the valve carriage (5) so its tabs slip into the
grooves on the narrow end of the actuator pistons
(11). See Fig. 9.
10. Align the valve gasket (4{) and cover (2) with the
six holes in the center housing (1). Secure with six
screws (3), using a Torx (T20) screwdriver or 7
mm (9/32”) socket wrench. Torque to 50–60 in-lb
(5.6–6.8 N.m). See Fig. 8.
To Next Page
Loading...
