24
308-262
Air Motor Service
Air Valve Service
Disassembly
1.
Remove the screws (25) holding the air valve
housing (5) to the cylinder (2). Be careful not to
drop the valve cup (7) as you remove the housing;
the cup can be easily damaged. See Fig. 12.
2.
Remove the large o-ring (21*), and two small
o-rings (30*) from the valve housing (5).
3.
Remove the two clips (10) and pull out the spool
retainers (9). Note that the clips are inserted
through the spool retainers from the inside of the
valve housing (5). Remove the o-rings (33) from
the spool retainers.
4.
Push the spool (6) out of the housing (5). Remove
the two u-cups (31) from the spool.
5.
Remove the screws (28) holding the air valve plate
(8) to the cylinder (2). Be very careful not to drop
or damage the plate. Inspect the plate surface for
scratches.
6.
Remove the gasket (13) from the face of the
cylinder (2).
Reassembly
NOTE: u-cup assembly tool 191–754 is available. You
must use this tool to properly insert the u-cups. The
tool is included in Repair Kit 239–657.
1.
Install the air valve gasket (13*) and plate (8) on
the cylinder (2). Be sure the surface of the plate
facing outward is free of scratches or damage.
Torque the screws (28) oppositely and evenly to 4
to 6 in-lb (0.5 to 0.7 N-m).
2.
Insert the u-cup assembly tool into the open end of
the valve housing until it bottoms out, as shown in
the Detail in Fig. 12.
3.
Install the two u-cups (31*) on the spool (6*) with
the u-cup lips facing toward each other. Generous-
ly grease the spool and the inner diameter of the
housing (5). Install the spool in the housing, Posi-
tioned at either end of its travel. The spool should
not be centered.
NOTE: If the spool slides out of the other end of
the housing during assembly, slide the tool over
the exposed spool end and u-cup, and re-insert
the spool into the housing.
4.
Grease the top and bottom recesses of the hous-
ing (5). Install an o-ring (33*) on each spool retain-
er (9). Place the retainers in the recesses and
secure with the clips. The clips must be fully
inserted from the inside surface of the housing.
5.
Lubricate the o-ring grooves in the valve housing
(5) with grease, then install the large o-ring (21*)
and two small o-rings (30*). The grease holds the
o-rings in place.
6.
Grease the valve cup (7*) and the valve plate (8).
Orient the cup as shown in Fig. 12. Place the cup
on the valve plate so its position corresponds to
the position of the spool (see step 3).
7.
Place the air valve housing (5) on the cylinder (2).
The spool (6*) must engage the valve cup (7*), or
the valve will not fit correctly. If necessary, move
the cup to engage the spool.
8.
Install the screws (25) and torque oppositely and
evenly to 14 to 17 in-lb (1.6 to 1.9 N-m). Be sure
the o-rings (21* and 30*) do not slip out of the
grooves on the housing.
