Troubleshooting guide

11
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The Charging, Air Treatment and Storage System: Compressors
Maintenance Schedule and Usage Guidelines
Regularly scheduled maintenance is the single most important factor in
maintaining the air brake charging system.
Depending on the vehicle’s air use, the table below shows examples of
compressors spec’d, and typical discharge line lengths and maintenance
intervals. See your compressor and/or air dryer Service Data Sheet for
more information.
Air Dryer
Maintenance
Schedule
Air Compressor
Spec’d
Reservoir
Draining
Discharge Line
Length
2
1
3
4
a. Compressor and/or air dryer upgrades are recommended in cases
where duty cycle is greater than the normal range (for the examples
above). For certain vehicles/applications, where turbo-charged inlet
air is used, a smaller size compressor may be permissible.
b. To counter above normal temperatures at the air dryer inlet (and
resultant oil-vapor passing upstream in the air system), replace the
discharge line with either a larger diameter and/or longer length
line. This helps reduce the temperature of the discharged air. If
suffi cient cooling occurs, the oil-vapor condenses and can be
removed by the air dryer. Discharge line upgrades are not covered
under warranty. Note: To help prevent discharge line freeze-ups,
shorter discharge line lengths, or insulation, may be required in cold
climates. See Bendix Bulletins TCH-008-021 and TCH-008-022,
for more information.
c. With increased air demand, the air dryer cartridge needs to be
replaced more often.
(5 or less axles) (5 or less axles) (8 or less axles) (12 or less axles)
Discharge line:
6 ft. @ ½ in. Inner Diameter
(oil carry-over control
suggested upgrade
b
: 9 ft.
@
5
/
8
in.)
2
Discharge line:
9 ft. @ ½ in. Inner Diameter
(oil carry-over control suggested
upgrade
b
: 12 ft. @
5
/
8
in.)
Discharge line:
12 ft. @ ½ in. Inner Diameter
(oil carry-over control suggested
upgrade
b
: 15 ft. @
5
/
8
in.)
Discharge line:
15 ft. @
5
/
8
in. Inner Diameter
(oil carry-over control suggested
upgrade
b
: 15 ft. @ ¾ in.)
Examples of Typical Compressors Spec’d
a
:
1
Compressor with up
to 25% duty cycle
Compressor with up
to 25% duty cycle
Compressor with less
than 15% duty cycle
(builds air pressure during 15% or
less of the engine running time.)
Compressor with less
than 25% duty cycle
(builds air pressure during 25% or
less of the engine running time.)
Bendix
®
BA-921
®
air compressor
Bendix
®
Tu-Flo
®
550 air compressor
Bendix
®
BA-922
®
air compressor
Bendix
®
Tu-Flo
®
750 air compressor
Bendix
®
DuraFlo 596
™
air compressor
Low Air Use
e.g. Line haul single
trailer without air
suspension; air over
hydraulic brakes.
Medium
Air Use
e.g. Line haul
single trailer with
air suspension, RV,
school bus.
High Air Use
e.g. Double/triple
trailer, open highway
coach, (most) pick-up &
delivery, yard or terminal
jockey, off-highway,
construction, loggers,
concrete mixer, dump
truck, fi re truck.
Very High
Air Use
e.g. City transit
bus, refuse, bulk
unloaders, low boys,
urban region coach,
central tire infl ation.
4
Replace Every 2 Years
c
Replace Every Year
c
Replace Air Dryer Cartridge Every 3 Years
c
3
Drain Reservoirs Every Month to 90 Days
Drain Reservoirs Every Month
Oil
Passing
Concerns?
Use the BASIC
Test Kit:
Bendix P/N
5013711
BASIC Test acceptable range:
≤ 3 oil units per month.
BASIC Test acceptable range:
≤ 5 oil units per month.