4211-7, S.7
Operation & Maintenance Instruction
Page 9 of 10
September, 2017
IMPORTANT:
The locking sealant is to be applied according
to the instructions of the locking sealant manufacturer.
7.3.10 Install the
1
/
2
" jam nut (10) on the threaded end of the
piston stem (17) and snug it against the washer (11). Using
a
7
/
8
" open end wrench on the flats of the piston stem (17) to
hold the sub-assembly, torque the
1
/
2
" jam nut (10) to 30 to
35 foot-pounds.
NOTE:
The diaphragm - piston - follower - piston stem sub-
assembly (10 to 17)
MUST BE
set aside to permit the locking
sealant to cure. See locking sealant manufacturer
instructions for proper curing time.
7.3.11 Apply a light coating of Number 2 Silicone Grease,
Wabtec Corporation Specification M-7680-2, to the surfaces of
a
NEW
11
/
16
" O.D. o-ring (18). Also, fill the o-ring groove on the
piston stem (17) and lightly lubricate the lower bushing of the
housing (25), the bushing which the o-ring will contact, with the
lubricant.
7.3.12 Install the
NEW
lubricated
11
/
16
" O.D. o-ring (18) in its
groove on the piston stem (17). Remove any excess lubricant by
wiping with a clean, dry, lint-free cloth.
7.3.13 Install the diaphragm - piston - follower- piston stem
sub-assembly (10 to 18) as a unit into the housing (19) so
that the piston stem with o-ring (17, 18) enters the bushing in
the housing (19) and the outer bead of the diaphragm (15) fits
into the bead groove of the housing (19). Apply finger
pressure to seat the bead of the diaphragm (15) in its groove.
7.3.14 Install the control spring (8) over the exposed threads of
the piston stem (17) so that the spring (8) seats on the top of
the jam nut (10).
7.3.15 Install a
NEW
diaphragm (7) in place in the filling piece (9)
so that the metal spring cup of the diaphragm faces the filling
piece (9) and the bead of the diaphragm (7) enters the bead
groove of the filling piece (9). Apply finger pressure to seat the
bead of the diaphragm in its groove.
7.3.16 Place the diaphragm clamping ring (6) over the
diaphragm (7) and on the filling piece (9) being sure that the
three screw holes of the clamping plate (6) are aligned with the
tapped holes in the filling piece (9).
7.3.17 Install three #8 x
1
/
2
" button head screws (5) through the
aligned holes of the diaphragm clamping ring (6) and the filling
piece (9). Equally tighten the screws to maintain alignment
and secure the sub-assembly. Torque the screws to 20-23
in-lbs.
7.3.18 Install a
NEW
5
1
/
4
" O.D. o-ring (4) into its groove in
the filling piece (9). Apply Number 2 Silicon Grease,
Wabtec Corporation Specification M-7680-2 to the O-ring
and groove.
7.3.19 Place the filling piece - diaphragm sub-assembly (4
to 9) onto the housing (19) and over the spring (8) so that the
spring (8) fits inside the spring cup of the diaphragm (7) and
so that the mounting screw holes of the filling piece (9) are
aligned with the four screw holes of the housing (19).
7.3.20 Place the body (2) onto the filling piece (9) so that the
exhaust port of the body (2) faces the same direction as the
VX Vent Valve tab on the filling piece (9), then install four
3
/
8
"
x 1
1
/
2
" hex. head cap screws (1) through the aligned holes
of the housing (19) and filling piece (9) and into the body
(2). Equally tighten the screws (1) in an alternating
fashion to 20-25 ft-lbs.
7.3.21 Install a
NEW
wire mesh strainer (3) in place in the
inlet port #1 of the body.
8.0 TESTING AND ADDITIONAL INFORMATION
8.1
IMPORTANT:
After the VX Vent Valve Portion, Part
No.
699505, has been assembled, BUT BEFORE it is
returned to service, it MUST PASS a series of test
following the procedures of the current issue of the
Wabtec Corporation Test Specification T-4322-O.
8.2
IMPORTANT:
Whenever the VX Vent Valve Portion, Part
No. 699505, is removed from an equipment arrangement
for any reason, and it is reinstalled or replaced with a
NEW or repaired and tested VX Vent Valve Portion, a NEW
mounting gasket
MUST BE
used. This 1" flange fitting
gasket, Part No. 93986, is not a part of the VX Vent Valve
Portion, but it is included in the Rubber Parts Kit, Part No.
654716.
8.3
IMPORTANT:
Whenever the VX Vent Valve Portion, Part
No. 699505, is removed from an equipment for any
reason, and it is reinstalled or replaced with a NEW or
repaired and tested VX Vent Valve Portion, a stationary
vehicle test
MUST BE
made to be sure that the VX Vent
Valve Portion functions properly in the total equipment
arrangement.
8.4 Consult your Wabtec Corporation Representative
if additional information is required.
