Bendix Commercial Vehicle Systems TU-FLO 700 COMPRESSOR 10/04 - Manual (Page 4)

4
DISCHARGE LINE TEMPERATURE
When the temperature of the compressed air that enters
the air dryer is within the normal range, the air dryer can
remove most of the charging system oil. If the temperature
of the compressed air is above the normal range, oil as oil-
vapor is able to pass through the air dryer and into the air
system. Larger diameter discharge lines and/or longer
discharge line lengths can help reduce the temperature.
The air dryer contains a filter that collects oil droplets, and a
desiccant bed that removes almost all of the remaining water
vapor. The compressed air is then passed to the air brake
service (supply) reservoir. The oil droplets and the water
collected are automatically purged when the governor
reaches its "cut-out" setting.
For vehicles with accessories that are sensitive to small
amounts of oil, we recommend installation of a Bendix
®
PuraGuard ® QC ™ oil coalescing filter, designed to minimize
the amount of oil present.
LUBRICATION
Since all Tu-Flo ® 700 compressors are connected to the
engine’s pressurized oil system, a continuous flow of oil is
provided to the compressor, which is eventually returned to
the engine. Oil is fed into the compressor in various ways,
for example: through the rear end cover, the drive end of the
crankshaft or through the front flange adapter. An oil passage
in the crankshaft conducts pressurized oil to the precision
sleeve main bearings and to the connecting rod bearings.
Splash lubrication of the cylinder bores, connecting rod wrist
pin bushings, and the ball type main bearings, on some
models, is obtained as oil is forced out around the crankshaft
journals by engine oil pressure.
Check the exterior of the compressor for the presence of oil
seepage and refer to the TROUBLESHOOTING section for
appropriate tests and corrective action.
OIL PASSING
All reciprocating compressors currently manufactured will
pass a minimal amount of oil. Air dryers will remove the
majority of oil prior to entrance into the air brake system.
For particularly oil sensitive systems the Bendix
® PuraGuard ®
QC ™ oil coalescing filter can be used in conjunction with a
Bendix air dryer.
If compressor oil passing is suspected, refer to the
TROUBLESHOOTING section and TABLE A for the
symptoms and corrective action to be taken. In addition,
Bendix has developed the "Bendix Air System Inspection
Cup" or BASIC test to help substantiate suspected excessive
oil passing. The steps to be followed when using the BASIC
test are presented in APPENDIX A at the end of the
TROUBLESHOOTING section.
FIGURE 2 - INTAKE
INTAKE
STRAINER
STROKE
TO RESERVOIR
INLET VALVE
UNLOADER
PLUNGER
TO GOVERNOR
INTAKE
STRAINER
STROKE
TO RESERVOIR
TO GOVERNOR
PISTON
DISCHARGE
VALVE
UNLOADER
PLUNGER
STROKE
INLET VALVE
TO RESERVOIR
UNLOADER
PLUNGER
INTAKE
STRAINER
TO GOVERNOR
PISTON
DISCHARGE
VALVE
DISCHARGE
VALVE
INLET VALVE
FIGURE 3 - COMPRESSION
FIGURE 4 - UNLOADING
PISTON