Bendix Commercial Vehicle Systems SR-4 SPRING BRAKE CONTROL VLV 7/07 - Manual (Page 6)

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DISASSEMBLY TYPE 2 SR-4 ™ VALVE
(REFER TO FIG. 5)
1. Remove and save the eight cap screws holding the two
spring retainers in place. Remove the spring retainers
and remove the springs (1 & 2) taking note of the
differences and from which cavity it was removed. (One
is color coded green the other white.)
2. With a pair of pliers, grasp the raised surface of the two
piston assemblies (3) and remove them from the valve
body housing.
3. Refer to Fig. 5. With a 5/16 inch Allen Wrench, remove
the four 3/8 inch pipe plugs from the SR-4 ™ valve.
(Three are in the main body and one is in the end cap.)
Trailers without anti-compounding feature will not have
a check valve in the end cover. Remove the four check
valve assemblies (4), one under each of the 3/8 inch
pipe plugs.
4. Note and mark the position of the end cover to the
body. Remove the four cap screws that retain the end
cover. Remove the end cover from the body. Remove
the sealing ring (5) from the end cover.
5. Remove the large piston from its bore by grasping the
web with a pair of pliers and pulling. Remove the spring
(6) from the base of the bore. Remove the o-rings (7 &
8) from the piston.
6. Remove the check valve assembly from the main body
by lightly clamping the body in a vise and turning the
check valve assembly counterclockwise with a 1-1/4
inch end wrench. Remove the spring (9) and the inlet/
exhaust valve (10) from the housing. Remove the o-ring
(11) from the O.D. of the check valve assembly.
7. With a pair of I.D. snap ring pliers, remove the snap
ring in the end of the check valve assembly. Remove
the spring seat, the conical spring (12) and the check
valve (13).
8. Using a Phillips head screwdriver, remove the Phillips
head screw and the diaphragm washer from the
exhaust port of the SR-4
™ valve body. Remove the
diaphragm (14).
CLEANING AND INSPECTION
1. Using mineral spirits or an equivalent solvent, clean
and thoroughly dry all metal parts.
2. Inspect the interior and exterior or all metal parts that
will be reused for severe corrosion, pitting or cracks.
Superfi cial corrosion and/or pitting on the exterior
portion of the valve is acceptable.
3. Inspect the bores of the valve housing for deep scuffi ng
or gouges.
FIGURE 5 INSETS - VIEWS OF LOCATION OF THE FOUR CHECK VALVE ASSEMBLIES (4)
END CAP
EXHAUST
BODY
1
2
3
5
4
6 7
9
11
10
12
8
14
3
13
4
4
4
END CAP
EXHAUST
END CAP