Bendix Commercial Vehicle Systems TU-FLO 501 AIR COMPRESSOR 9/04 - Manual (Page 6)

6
EVERY 24 MONTHS, 7200 OPERATING HOURS
OR AFTER EACH 200,000 MILES
Perform a thorough inspection as indicated below and
depending upon the results of this inspection or experience,
disassemble the compressor, clean and inspect all parts
thoroughly, repair or replace all worn or damaged parts
using only genuine Bendix replacements or replace the
compressor with a genuine Bendix remanufactured unit.
IMPORTANT - Should it be necessary to drain the engine
cooling system to prevent damage from freezing, the cylinder
head of the compressor must also be drained.
GENERAL SERVICE CHECKS
Inspection
It is of the utmost importance that the compressor receives
a clean supply of air. The air strainer must be properly
installed and kept clean. If the compressor intake is connected
to the engine air cleaner, supercharger, etc., these
connections must be properly installed and maintained.
Check the compressor mountings to be sure they are secure.
Check the drive for proper alignment, belt tension, etc.
Inspect the oil supply and return lines. Be sure these lines
are properly installed and that the compressor is getting
the proper supply of oil, and just as important, that the oil is
returning to the engine. Check the coolant lines to and from
the compressor and see that the cooling fins on the
crankcase are not clogged with dirt, grease, etc. Check
the unloader mechanism for proper and prompt operation.
Operating Tests
Vehicles manufactured after the effective date of FMVSS
121, with the minimum required reservoir volume, must have
a compressor capable of raising air system pressure from
85-100 P.S.I. in 25 seconds or less. This test is performed
with the engine operating at maximum governed speed.
The vehicle manufacturer must certify this performance on
new vehicles with appropriate allowances for air systems
with greater than the minimum required reservoir volume.
Air Leakage Tests
Leakage past the discharge valves can be detected by
removing the discharge line, applying shop air back through
the discharge port and listening for escaping air. Also, the
discharge valves and the unloader pistons can be checked
for leakage by building up the air system until the governor
cuts out, then stopping the engine. With the engine stopped,
listen for escaping air at the compressor intake. To pinpoint
leakage if noted, apply a small quantity of oil around the
unloader pistons. If there is no noticeable leakage at the
unloader pistons, the discharge valves may be leaking. If
the compressor does not function as described above, or
leakage is excessive, it is recommended that it be returned
to the nearest authorized Bendix Distributor for a factory
remanufactured compressor. If this is not possible, the
compressor can be repaired using genuine Bendix
replacement parts, in which case, the following information
should prove helpful.
REMOVING AND DISASSEMBLY
Removing
These instructions are general and are intended to be a
guide, in some cases additional preparations and
precautions are necessary. Chock the wheels of the vehicle
and drain the air pressure from all the reservoirs in the
system. Drain the engine cooling system and the cylinder
head of the compressor. Disconnect all air, water and oil
lines leading to and from the compressor. Remove the drive
gear(s) or pulley from the compressor crankshaft using a
gear puller. Inspect the pulley or gear and associated parts
for visible wear or damage. Since these parts are precision
fitted, they must be replaced if they are worn or damaged.
DISASSEMBLY
General
Remove road dirt and grease from the exterior of the
compressor with a cleaning solvent. Before the compressor
is disassembled, the following items should be marked to
show their relationship when the compressor is assembled.
Mark both the front and rear end cover in relation to the
crankcase. Mark the drive end of the crankshaft in relation
to the front end cover and the crankcase. Mark the cylinder
head in relation to the crankcase. Mark the base plate or
base adapter in relation to the crankcase.
FIGURE 10 - TU-FLO ® 501 AIR COMPRESSOR (THRU
DRIVE) EXPLODED VIEW