Operation & Maintenance Instruction
August, 2003
Page 13 of 24
4225-50, S.6
7.5.2
Using #2 Silicone Grease, Wabtec Corporation
Specification M-07680-02, coat the surfaces of four NEW
1
1
/
2
" O.D. o-rings (47). Also, lightly lubricate the o-ring grooves
of the emergency accelerated release spool valve (48) and
the spool valve bushing surfaces of the body (58).
7.5.3
Install the four NEW, lubricated 1
1
/
2
" O.D. o-rings
(47) into their grooves on the emergency accelerated release
spool valve (48).
7.5.4
Install the emergency accelerated release spool
valve (48) with o-rings (47) into its bush in the body (58),
closed end first.
7.5.5
Install the emergency accelerated release spool
valve spring (46) into the spool valve (48).
7.5.6
Apply #2 Silicone Grease, Wabtec Corporation
Specification M-07680-02, to the surfaces of a NEW 1
1
/
2
"
O.D. o-ring (44) and lightly lubricate the o-ring groove of the
cap nut (45).
7.5.7
Install the NEW lubricated 1
1
/
2
" O.D. o-ring (44) into
its groove on the cap nut (45).
7.5.8
Install the cap nut with o-ring (45 & 44) into the body
(58) to secure the spring (46) and accelerated release spool
valve (48) with o-rings (47) in place. Using a
7
/
8
" square wrench,
tighten the cap nut (45) between 55 and 65 foot-pounds of
torque.
7.5.9
Install the emergency wear rings (11 & 12) on the
emergency piston (10).
IMPORTANT:
Care should be taken when expanding or
opening the wear rings during installation onto the emergency
piston. Do not overexpand the rings causing them to deform
which would result in difficult installation of the piston into
the bore. The protective ring should be installed with the gap
facing the slide valve area of the emergency piston. The
positioning of the rings will ease the assembly.
7.5.10 Install a NEW emergency piston diaphragm (5) on
the emergency piston (10) so that the piece number on the
diaphragm is facing away from the piston.
7.5.11 Lightly coat the threads of the
5
/
8
" x 1" hex head
screw (3) with LOCTITE Sealant TL-242, Wabtec Corporation
Specification M-07499-05. Install the cap screw (3) through
the diaphragm follower (4) and into the piston (10) to secure
the piston (10), diaphragm (5) and follower (4) together. Hand
tighten the cap screw (3) and flip the diaphragm (5) in the
opposite direction so that the large cone shaped opening is
facing the piston (10). Torque the screw (3) between 45 and
50 foot-pounds.
7.5.12 Insert the emergency slide valve spring (7) into the
emergency slide valve (8).
7.5.13 Carefully place the emergency slide valve with spring
(8 & 7) on the stem of the piston (10) and secure the parts in
place by installing the
3
/
32
" x
3
/
4
" cylindrical spring pin (6).
7.5.14 Using a foam-tipped 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
emergency slide valve (8).
7.5.15 Evenly spread a light coating of the Triple Valve Oil
on the slide valve bushing seat of the body (58).
7.5.16 Evenly spread a light coating of Triple Valve Oil over
the guide portion of the stem and piston end of the piston (10).
IMPORTANT:
Care must be taken when compressing the
slide valve spring (7) in preparation for inserting the emergency
piston assembly (3 to 10) into the body bushing. While using
minimal force, the assembly must be aligned squarely to
prevent any wedging or distortion. The slide valve face (8)
must be retracted from the bushing face as long as possible.
7.5.17 Install the diaphragm - piston - emergency slide valve
assembly (3 to 10) into the body (58). Exercise care so that
NO damage is done to the emergency slide valve bushing
seat.
7.5.18 Using the pressure of the thumb or finger, position
the sealing bead of the diaphragm in the diaphragm bead
groove of the body (58).
7.5.19 Coat the surfaces of five NEW 1
3
/
16
" O.D. o-rings
(15) with #2 Silicone Grease, Wabtec Corporation
Specification M-07680-02. Also lightly lubricate the o-ring
grooves of the high pressure spool valve (16) and the bearing
surfaces of the spool valve bushing of the body (58).
7.5.20 Install the five NEW lubricated 1
3
/
16
" O.D. o-rings
(15) into their grooves on the high pressure spool valve (16).
