5
287691 the revised check valve assemblies are included
in the kit and the old ones should be discarded. If the old
ones are being reused, the following applies:
1. Insert the rubber check valve (1) into the spring guides
(2). See Fig. 7.
2. Position the check valve springs (3) into the spring
guides and over the end of the rubber check valve (1)
with a twisting motion.
3. Drop the check valve and guide assemblies into their
respective bores in the valve body and install the two
3/8” socket head pipe plugs (18) and torque from 140
to 170 inch pounds.
REASSEMBLY OF CURRENT DESIGN CHECK VALVES
(Figure 8)
1. Assemble the springs to each of the check valves with
a twisting motion.
2. Drop the assemblies into their respective bores in the
valve body and install the 3/8” pipe plugs. (19)
REASSEMBLY OF CONTROL PISTON
1. Insert
the
fl at rubber inlet and exhaust valve (5) into the
valve body.
NOTE: The fl at side of the valve with the four ears
protruding rests against the inlet and exhaust valve
seat.
2. Install the inlet and exhaust valve spring (6) making
sure the spring is aligned and rests evenly on the four
ears of the inlet and exhaust valve.
3. Install the o-ring (7) in its proper groove on the reser voir
port fi tting (15).
4. Properly align the inlet and exhaust valve spring in the
recess at the end of the reservoir port fi tting. Install the
fi tting and torque from 200 to 300 inch pounds.
5. Install the three o-rings (1) and (2) in their respective
grooves on the control piston (14).
6. Drop and position the piston spring (3) into the valve
body.
7. Making sure all parts are properly aligned, install the
control piston (14) in the valve body.
8. Re-install the control piston cover (12) in its proper
position. Reference instruction # 5 under Removal and
Disassembly of control piston, for proper positioning,
screws (13) should be torqued from 40 to 60 inch
pounds.
9. If so equipped, re-install the screw (19), washer (20),
and exhaust diaphragm (11) in the control piston exhaust
port. Torque screw from 15 to 25 inch pounds.
REASSEMBLY OF PRESSURE PROTECTION PISTON
1. Install the o-ring in its respective groove on the pressure
protection piston (8), and install the piston assembly in
the valve body.
2. Position the spring (9) and spring retainer (17) on top
of the pressure protection piston assembly, and secure
with the four round head machine screws (16). Screws
should be torqued from 20 to 30 inch pounds.
TESTING THE REBUILT SR-2
™
TRAILER SPRING
BRAKE VALVE
Test the rebuilt SR-2
™
trailer spring brake valve by
performing the operation and leakage tests outlined in the
Service Checks section of this manual.
WARNING! PLEASE READ AND FOLLOW
THESE INSTRUCTIONS TO AVOID PERSONAL
INJURY OR DEATH:
When working on or around a vehicle, the following
general precautions should be observed at all times.
1. Park the vehicle on a level surface, apply the
parking brakes, and always block the wheels.
Always wear safety glasses.
2. Stop the engine and remove ignition key when
working under or around the vehicle. When
working in the engine compartment, the engine
should be shut off and the ignition key should be
removed. Where circumstances require that the
engine be in operation, EXTREME CAUTION should
be used to prevent personal injury resulting from
contact with moving, rotating, leaking, heated or
electrically charged components.
1
2
3
FIGURE 7 -
OLD STYLE
FIGURE 8 -
NEW STYLE
