10
OPERATION
Air fl ow in the normal direction moves the check valve
from its seat, and the fl ow is unobstructed. Flow in the
reverse direction is prevented by the seating of the ball or
wafer-type disc, which is caused by a drop in up-stream
air pressure and assisted by the spring.
PREVENTATIVE MAINTENANCE
Every six months, 1,800 operating hours or every 50,000
miles inspect all parts.
Replace any check valves leaking or showing signs of wear
or deterioration. Check for proper operation.
OPERATION & LEAKAGE CHECKS
NOTE: Depending upon installation, it may be easier or
necessary to completely remove check valves so that the
following checks may be made.
With air pressure present at outlet side of check valve and
the inlet side open to atmosphere, coat the open end of
the check valve with soap suds; a 1" bubble in 5 seconds
is permissible.
If the check valve does not function as described, or
leakage is excessive, it is recommended that it be replaced
with a new genuine Bendix part available at any Bendix
parts outlet.
REMOVAL
Block and hold vehicle by means other than air brakes.
Completely drain all reservoirs.
Disconnect air lines at single check valve and remove.
DISASSEMBLY/ASSEMBLY
Note: There are no Disassembly/Assembly procedures for
SC-3
™
valves. They are non-serviceable items. If a valve
does not meet the Operational and Leakage tests, it should
be replaced at any authorized Bendix parts outlet.
TESTING AND TROUBLESHOOTING
Perform “Operating and Leakage Checks”.
