Operation & Maintenance Instruction
August, 2003
Page 19 of 24
4225-50, S.6
7.7
ASSEMBLY of ABDX-SS SERVICE PORTION
See Figure 13
7.7.1
Service Diaphragm Piston
7.7.2
Install the service piston rings (17) on the service
piston (16).
IMPORTANT:
Care should be taken when expanding or
opening the service piston rings during installation onto the
service piston. Do not overexpand the rings causing them to
deform which would result in difficult installation of the piston
into the bore. The service piston ring should be installed with
the gap facing the slide valve area of the service piston. The
positioning of the rings will ease the assembly.
7.7.3
Position a NEW diaphragm (6) on the service piston
(16) so that the part number on the diaphragm (6) faces away
from the piston (16). After positioning the diaphragm bead
into the groove of the piston, flip the diaphragm (6) so that
the large cone shaped opening is facing the follower (5).
7.7.4
Position the diaphragm follower (5) on the diaphragm
(6) and piston (16).
7.7.5
Lightly coat the threads of the
5
/
8
" x 1" hex head cap
screw (4) with Loctite Sealant TL-242, Wabtec Corporation
Specification M-07499-05. Install the cap screw (4) through
the diaphragm follower (5) and into the piston (16) to secure
the piston (16), diaphragm (6) and follower (5) together. Hand
tighten the cap screw (4) and flip the diaphragm (6) in the
opposite direction so that the large cone shaped opening is
facing the piston (16). Torque the screw (4) between 45 and
50 foot-pounds.
7.7.6
Using a foam-tipped swab applicator, evenly spread
a light coating of Triple Valve Oil, Wabtec Corporation
Specification M-07611-20 (AAR Specification M-912) around
the surfaces of the piston spring guide (10) and the bearing
surfaces of the piston bushing.
7.7.7
Install the piston spring guide (10), closed end first,
into the open end of the service piston (16).
7.7.8
Install the piston spring (9) and spring seat (8) into
the open end of the spring guide (10) and secure the parts in
place by installing the spring retainer (7).
7.7.9
Place the slide valve spring (12) on the holding fixture,
Part No. 564522, as shown in Figure 8.
7.7.10 Using a foam-tipped swab applicator, evenly
spread a light coating of Triple Valve Oil, Wabtec
Corporation Specification M-07611-20, (AAR Specification
M-912) on the face of the graduating valve (14) and over
the graduating valve seat of the slide valve (15).
7.7.11 Install the graduating valve spring (13), graduating
valve (14), and slide valve (15) on to the piston (16).
7.7.12 Place the piston assembly on the slide valve spring
(12) which is still in the holding fixture.
7.7.13 Make sure that the graduating valve (14) is on its
seat in the slide valve (15) and that the slide valve side wings
are down tight in the fixture.
7.7.14 Install the
3
/
32
" x 1" cylindrical spring pin (11) through
the pin holes of each of the wings of the slide valve (15) and
the aligned pin hole of the slide valve spring (13). With the
aid of the pin driver supplied with the holding fixture, Part No.
564522, secure the pin (11) in place.
7.7.15 Remove the assembly from the holding fixture.
7.7.16 Using a foam-tipped swab applicator, evenly spread
a light coating of Triple Valve Oil, Wabtec Corporation
Specification M-07611-20 (AAR Specification M-912) over the
face of the slide valve (15) and the service piston rings (17)
on the service piston (16). Also apply a light coating of the
Triple Valve Oil to the slide valve seat of its bushing in the
body (49), and to the collars and fins of the piston (16) near
the piston head.
IMPORTANT:
Care must be taken when compressing the
graduating valve and slide valve in preparation for inserting
the service piston assembly with rings (4 to 17) into the body
bushing. While using minimal force, the assembly must be
aligned squarely to prevent any wedging or distortion. The
slide valve face (15) must be retracted from the bushing face
as long as possible. Care must be taken not to damage the
slide valve seats.
7.7.17 Install the piston - diaphragm - slide valve assembly
(4 to 17) into the body (49) from the top, exercising care so
that NO damage is done to the slide valve seat.
