Air Brake System - Cold Weather Operation Tips - BENDIX TU-FLO 550 COMPRESSOR Manual

Technical
Bulletin No.: TCH-008-021
Page: 1 of 2

Air Brake System - Cold Weather Operation Tips

Subject:
As the cold weather approaches, operators and fl eets alike begin to look to their vehicles with an eye
toward "winterization", and particularly what can be done to guard against air system freeze-up. Here
are some BASIC ™ "Tips" for operation in the cold weather.
Engine Idling
Avoid idling the engine for long periods of time! In addition to the fact that most engine manufacturers
warn that long idle times are detrimental to engine life, winter idling is a big factor in compressor discharge line
freeze-up. Discharge line freeze-ups account for a signifi cant number of compressor failures each year. The
discharge line recommendations under "Discharge Lines" are important for all vehicles but are especially so
when some periods of extended engine idling can not be avoided.
Discharge Lines
The discharge line should slope downward from the compressor discharge port without forming water traps,
kinks, or restrictions. Cross-overs from one side of the frame rail to the other, if required, should occur as close
as possible to the compressor. Fitting extensions must be avoided. Recommended discharge line lengths and
inside diameters are dependent on the vehicle application and are as follows.
Typical P&D, School Bus and Line Haul
The maximum discharge line length is 16 feet.
Length
6.0-9.5 ft.
9.5-12 ft. ½ in.
12-16 ft. 5/8 in.
If the discharge line length must be less than 6 feet or greater than 16 feet, contact your local Bendix
representative.
Appendix C
Bulletin
Effective Date: 11/1/92
I.D. Min. Other Requirements
½ in. None
Last 3 feet, including fi tting at the end of the
discharge line, must be insulated with ½ inch thick closed
cell polyethylene pipe insulation.
Last 3 feet, including fi tting at the end of the
discharge line, must be insulated with ½ inch thick
closed cell polyethylene pipe insulation.
A-19