Operation & Maintenance Instruction
August, 2003
Page 21 of 24
4225-50, S.6
(24) with Loctite Sealant TL-242, Wabtec Corporation
Specification M-07499-05. Install the
9
/
16
" nut (21) on the
threaded end of the piston (24) and torque the nut (21) between
40 and 55 foot-pounds.
7.7.39 Install the diaphragm - piston assembly (21 to 24),
piston end first into the filling piece (31). Be sure that the
bead of the diaphragm is properly seated in its groove on the
filling piece (31). Use finger pressure to properly seat the
diaphragm bead.
7.7.40 Install the wear protection disk (20) over the hex nut
(21). The disc lies on the follower (22) and is not held in
place by any means. The body will have to be positioned so
the disc remains in place while installing the cover (19).
7.7.41 Install a NEW
11
/
16
" O.D. ring gasket (26) into its
groove on the cover mounting face of the filling piece (30).
7.7.42 Place the service accelerated release valve cover
(19) in position on the filling piece (30). Be sure that all parts
are properly positioned, then using the four
1
/
2
" x 2
3
/
4
" hex
head screws (18), secure the cover and filling piece
assemblies (19 to 31) to the body (49). Equally torque the
screws (18) between 35 and 55 foot-pounds.
7.7.43
Release Valve Portion Assembly
See Figure 8
7.7.44 Using #2 Silicone Grease, Wabtec Corporation
Specification M-07680-02, lightly lubricate the surfaces
of three NEW
3
/
4
" O.D. o-rings (17). Also lightly lubricate
the o-ring grooves of the spool valve (18) and the bearing
surfaces of the spool valve bushing of the release valve
portion body (35).
7.7.45 Install the three NEW lubricated
3
/
4
" O.D. o-rings
(17) into their grooves on the spool valve (18).
7.7.46 Install the spool valve spring (16) and spool valve with
o-ring assembly (17, 18) into the release valve body (35).
7.7.47 Install the lifter spring (23) and lifter (26) into the
proper cavity in the release valve body (35).
7.7.48 Install a NEW reset check valve (21) and the check
valve spring (22) into the proper cavity of the release valve
body (35).
7.7.49 Install the check valve spring (19) and a NEW
retaining check valve (20) in the proper cavity of the release
valve body (35). The seat for the retaining check valve is
located in the bottom cover.
7.7.50 Install the bottom cover sleeve (34) and secure a
NEW seal (32) with a NEW
3
/
16
" x
1
/
2
" aluminum pop rivet
(33) in the bottom cover (31).
7.7.51 Install a NEW valve seal (30), stem and end plate
(27), a NEW
5
/
8
" O.D. ring gasket (29) and a NEW bottom
cover gasket (28) in place in or on the bottom cover (31).
7.7.52 Carefully position the bottom cover assembly (27 to
34) on the body (35) without applying heavy pressure, then
insert the five
3
/
8
" x 1
3
/
4
" hex head cap screws (15) into the
cover (31). Observe the retaining check valve (20) to be sure
that it is in alignment with the check valve seat in the cover
(31). Also be sure that the reset check valve spring (22) is
properly positioned in the cover (31), then hand press the
cover (31) to the body (35) and secure it in place by equally
tightening the five
3
/
8
" x 1
3
/
4
" hex head cap screws (15) to a
torque value between 15 and 25 foot-pounds.
7.7.53 Using #2 Silicone Grease, Wabtec Corporation
Specification M-07680-02, lightly coat the surfaces of a NEW
1
/
2
" O.D. o-ring (9) and three NEW
3
/
4
" O.D. o-rings (11). Also
lightly coat the o-ring grooves on the spool valve (10) and the
bearing surfaces of the spool valve bushing of the body (35).
7.7.54 Using an open end wrench to hold the spool valve
(10), install the piston (8) on the threaded end of the spool
valve (10).
7.7.55 Install the NEW lubricated
1
/
2
" O.D. o-ring (9) in
place on the piston (8), then install a NEW diaphragm (7) so
that the part number on the diaphragm faces away from the
piston toward the threaded end of the spool valve (10).
7.7.56 Install the diaphragm follower (6) and a NEW
3
/
8
-16
self-locking hex nut (5) on the threaded end of the spool
valve (10). Secure the parts together by torquing the nut (5)
to 12 to 14 foot-pounds.
7.7.57 Install the three NEW lubricated
3
/
4
" O.D. o-rings
(11) into the three o-ring grooves of the spool valve (10).
7.7.58 Install the diaphragm piston assembly (5 to 11) into
the body (35). Be sure that the bead of the diaphragm (7) is
