21
A-3
Compressor with up to 25% duty cycle
Footnotes:
1. With increased air demand the air dryer cartridge needs to be
replaced more often.
2. Use the drain valves to slowly drain all reservoirs to zero psi.
3. Allow the oil/water mixture to fully settle before measuring oil
quantity.
4. 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 one of a larger diameter and/or longer length.
This helps reduce the air's temperature. If sufficient 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
Recom- Recom- Acceptable
Typical Discharge
mended mended Reservoir
Compressors
Line
Air Dryer
Reservoir
Oil Contents
3
No. of
Spec'd
Cartridge
Drain
at Regular
Axles
Replacement
1
Schedule
2
Drain Interval
High Air Use
Low Air Use
e.g. Double/triple trailer, open
highway coach/RV, (most)
pick-up & delivery, yard or
terminal jockey, off-highway,
construction, loggers, concrete
mixer, dump truck, fire truck.
e.g. Line haul single trailer
w/o air suspension, air over
hydraulic brakes.
e.g. Line haul single trailer
with air suspension,
school bus.
5
or
less
5
or
less
8
or
less
12
or
less
Table A: Maintenance Schedule and Usage Guidelines
Recom-
mended
Every
Month -
Max of
every 90
days
Every
Month
Every 3
Years
Every 2
Years
Every
Year
I.D.
Vehicle Used for:
Column 1
Column 2
Column 3
Column 4
Column 5
Regularly scheduled maintenance
is the single most important factor in maintaining the air brake charging
system.
Length
6 ft.
1/2 in.
9 ft.
1/2 in.
12 ft.
1/2 in.
3/4 in.
12 ft.
BASIC test
acceptable
range:
5 oil units
per month.
See
Appendix
A.
For oil carry-over
control
4
suggested
upgrades:
5/8 in. 15 ft.
For oil carry-over
control
4
suggested
upgrades:
5/8 in. 9 ft.
For oil carry-over
control
4
suggested
upgrades:
5/8 in. 12 ft.
Compressor with less than 15% duty
cycle
Compressor with up to 25% duty cycle
Compressor with up to 25% duty cycle
Bendix
®
BA-921
®
or SNA-01
™
air compressor
Bendix
®
T
u-
Flo
®
550 air compressor
Bendix
®
T
u-
Flo
®
750 air compressor
Bendix
®
BA-922
®
,
or DuraFlo 596
™
air compressor
Bendix
®
BASIC
™
test
acceptable
range:
3 oil units
per month.
See
Appendix
A.
For the
BASIC
Test Kit:
Order
Bendix
P/N
5013711
e.g. City transit bus, refuse,
bulk unloaders, low boys,
urban region coach, central
tire inflation.
(See footnote 7)
Bulletins TCH-008-021 and TCH-008-022, included in Appendix B,
for more information.)
5. For certain vehicles/applications, where turbo-charged inlet air is
used, a smaller size compressor may be permissible.
6. Note: Compressor and/or air dryer upgrades are recommended
in cases where duty cycle is greater than the normal range (for
the examples above).
7. For correct compressor upgrades consult Bendix - Please note
that because a compressor is listed in the same area of the chart
it does not necessarily mean that it would be a suitable candidate
for upgrade purposes.
For Bendix
®
Tu-Flo
®
550 and 750 compressors, unloader service is
recommended every 250,000 miles.
