Service
16
309528L
Service
Repairing the Air Valve
Tool Required
•
Torque wrench
•
Torx (T20) screwdriver or 7 mm (9/32 in.) socket
wrench
•
Needle-nose pliers
•
O-ring pick
•
Lithium base grease
Disassembly
1.
Relieve the pressure.
2.
With a Torx (T20) screwdriver or 7 mm (9/32 in.)
socket wrench, remove the six screws (3), air valve
cover (2), and gasket (4†
◆
). See F
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 F
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). Remove the o-rings (17†
◆
) from the push
pins. See F
5.
Inspect the valve plate (8
◆
) in place. If damaged,
use a Torx (T20) screwdriver or 7 mm (9/32 in.)
socket wrench to remove the three screws (3).
Remove the valve plate (8
◆
) and, on aluminum cen-
ter housing models, remove the seal (9†). See F
6.
Inspect the bearings (12, 15) in place. See F
The bearings are tapered and, if damaged, must be
removed from the outside. This requires disassem-
bly of the fluid section. See page 22.
7.
Clean all parts and inspect for wear or damage.
Replace as needed. Reassemble.
Reassembly
1.
If you replaced the bearings (12, 15), reinstall as
explained on page 22. Reassemble the fluid section.
2.
On aluminum center housing models, 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 F
3.
Install the valve plate (8
◆
) in the cavity. On alumi-
num center housing models, 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
in.) socket wrench. Tighten until the screws bottom
out on the housing. See F
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 F
5.
Install a u-cup packing (10†
◆
) on each actuator pis-
ton (11), so the lips of the packings face the narrow
end of the pistons. See F
6.
Lubricate the u-cup packings (10†
◆
) and actuator
pistons (11). Insert the actuator pistons in the bear-
ings (12), wide end first. Leave the narrow end of
the pistons exposed. See F
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 F
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
F
9.
Install the valve carriage (5) so its tabs slip into the
grooves on the narrow end of the actuator pistons
(11). See F
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 in.) socket wrench. Torque to 50-60 in-lb
(5.6-6.8 N•m). See F
Air Valve Repair Kits 236273 (aluminum) and
255061 (sst) are available. Refer to the Repair Kit
Matrix parts section for the appropriate pump
size. Parts included in the kit are marked with a
symbol, for example (4†). Use all the parts in the
kit for the best results.
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.
