Bendix Commercial Vehicle Systems SR-1 SPRING BRAKE VALVE - Manual (Page 7)

7
LEAKAGE CHECK
With the air system fully charged and the parking control
valve in the “release” position, coat the exhaust port and
around the valve corner with a soap solution. Slight leakage
is permitted.
If the Bendix ® SR-1 ™ spring brake valve does not function
as described previously, or leakage is excessive, it is
recommended that it be repaired or replaced with a genuine
Bendix service replacement valve.
Note: A maintenance kit for the SR-1 spring brake valve is
available from any authorized Bendix outlet. All parts
necessary for minor repair are included.
REMOVAL
1. Prior to removing the SR-1 valve, apply the parking
brakes and drain all the vehicle reservoirs.
2. Identify all air lines before disconnecting.
3. Remove the two mounting bolts from the SR-1 valve
and remove the valve.
DISASSEMBLY (REFER TO FIGURE 1)
1. Remove the socket head pipe plug (1).
2. Remove the check valve spring (2) and the check valve
(4).
3. Remove the two phillips head screws and remove the
exhaust cover (5).
4. Separate the exhaust diaphragm (6) from the cover.
5. Remove the inlet and exhaust valve assembly (7).
6. Remove the inlet and exhaust valve cap nut (8) and
separate the cap nut o-ring (9).
7. Remove the valve stop (10) valve spring (11) and inlet
and exhaust valve (12).
8. Remove the four phillips head screws and lockwashers
that secure the cover to the body. Caution: the cover is
under a spring load, and should be held while removing
the screws.
9. Remove the cover (13) and the three piston springs
(14). Note: Some SR-1 valve piece numbers have one
large piston spring.
10. Remove the small piston (15) and the small and large
o-rings (16).
11. Remove the large piston (17). Remove piston o-rings
(18) & (19).
CLEANING & INSPECTION
1. Inspect all parts for excessive wear or deterioration.
2. Inspect the valve seats for nicks or burrs.
3. Check the springs for cracks or corrosion.
4. Replace all rubber parts and any part not found to be
serviceable during inspection. Use only genuine Bendix
replacement parts.
ASSEMBLY (REFER TO FIGURE 2)
Prior to assembly of the SR-1 spring brake valve, lubricate
all o-rings, o-ring grooves, and piston bores with Bendix
silicone lubricant BW-650-M piece number 291126.
Note: All torques specifi ed in this manual are assembly
torques and can be expected to fall off, after
assembly is accomplished. Do not retorque after
initial assembly torques fall.
1. Assemble the check valve (4), and valve spring (2) and
install in body.
2. Apply pipe sealant to the socket head pipe plug (1)
and install in the body. Tighten to 130-170 inch pounds
torque.
3. Install inlet and exhaust valve assembly (7) in valve
body.
4. Secure the exhaust cover (5) with two 10-24 phillips
head screws and lockwashers. Tighten to 20-30 inch
pounds torque.
5. Install exhaust diaphragm (6) into the exhaust cover.
6. Place inlet exhaust valve (12) in the body. Install the
valve spring (11) and valve stop (10).
7. Install o-ring (9) on cap nut and install cap nut (8) in
body. Tighten to 100-125 inch pounds torque.
8. Install the small and large o-rings (16) on the small
diameter piston (15) and install piston in the body.
9. Install large o-ring (18) and small o-ring (19) on the
large diameter piston and install piston in the body.
10. Install the piston springs (14) in their respective pistons.
11. Secure the cover to body using four 1/4"-20 phillips
head screws and lockwashers. Tighten to 50-80 inch
pounds torque.
TESTING THE REBUILT BENDIX ® SR-1 ™ SPRING
BRAKE VALVE
Test the rebuilt SR-1 spring brake valve by performing the
operation and leakage test outlined in the “Service Checks”
section of this manual.