Bendix Commercial Vehicle Systems TU-FLO 550 COMPRESSOR 6/08 - Manual (Page 9)

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material (5) from the cover plate, cylinder head and
crankcase.
1. Remove the unloader pistons (7), o-rings (6) and
springs (8).
2. Inspect the unloader piston bushings (9) for nicks,
wear, corrosion and scoring. It is recommended that
the compressor be replaced if it is determined that the
unloader bushing is damaged or worn excessively.
Before disassembling the discharge valve mechanism,
measure and record the discharge valve travel (from closed
to completely open).
3. If the measured discharge valve travel exceeds .046
inches, the compressor should be replaced. If the
discharge valve travel does not exceed .046, using a
9/16" Allen wrench, remove the discharge valve seats
(18), valves (17) and valve springs (16).
4. Remove the inlet valve stops (14), valves (17), valve
seats (11), valve springs (12) and gaskets (10). It is
recommended that a tool such as a J-25447-B, produced
by Kent Moore Tool Division Roseville, Michigan phone
1-800-328-6657, be used to remove the inlet valve
stop.
CRANKCASE BOTTOM COVER OR ADAPTER
DISASSEMBLY
1. Remove the cap screws (22) securing the bottom cover
or adapter (21). Tap with a soft mallet to break the
gasket seal. Scrape off any gasket material (20) from
the crankcase and bottom cover or adapter.
CONNECTING ROD DISASSEMBLY
Before removing the connecting rod, mark the connecting
rods (37) and their caps (39) to ensure correct reassembly.
The connecting rod and cap are a matched set therefore
the caps must not be switched or rotated end for end.
1. Remove the connecting rod bolts (40) and bearing caps
(39).
2. Push the pistons (26) with the connecting rods
(37) attached out the top of the cylinder bore of the
crankcase. Replace the bearing caps on the connecting
rods.
3. Remove the piston rings (23-25) from the piston. If
the piston is to be removed from the connecting rod,
remove the wrist pin Tefl on plugs (28) and press the
wrist pin (27) from the piston and connecting rod.
4. If the piston is removed from the rod, inspect the wrist
pin bore in the piston and bronze wrist pin bushing
(36) in the connecting rod. If excessive wear is noted
or suspected, replace the connecting rod and piston.
COMPRESSOR CRANKCASE DISASSEMBLY
1. Remove the key or keys (30) from the crankshaft (29)
and any burrs from the crankshaft where the key or keys
were removed. (Note: Through drive compressors may
have a crankshaft key at both ends.)
2. Remove the four cap screws (35) and lockwashers or
nuts and lockwashers that secure the rear end cover
(34) to the crankcase.
3. Remove the rear end cover (34), thrust washer (31) and
end cover oil seal ring (33), taking care not to damage
the bearing if present in the end cover.
4. If the compressor has ball type main bearings, press the
crankshaft (29) and ball bearings from the crankcase,
then press the ball bearings from the crankshaft.
5. Press the oil seal out of the compressor crankcase, if
so equipped.
CLEANING OF PARTS
GENERAL
All parts should be cleaned in a good commercial grade of
solvent and dried prior to inspection.
CYLINDER HEAD
Remove carbon deposits from the discharge cavity and
rust and scale from the cooling cavities of the cylinder head
body. Scrape all foreign matter from the body surfaces and
use shop air pressure to blow the dirt particles from the
cavities. Clean carbon and dirt from the inlet and unloader
passages. Use shop air to blow the carbon and dirt deposits
from the unloader passages.
OIL PASSAGES
Thoroughly clean all oil passages through the crankshaft,
crankcase, end covers, base plate or base adapter. Inspect
the passages with a wire to be sure. Blow the loosened
foreign matter out with air pressure.
INSPECTION OF PARTS
CYLINDER HEAD BODY
Inspect the cylinder head for cracks or damage. With the
cylinder head and head gasket secured to a fl at surface or
crankcase, apply shop air pressure to one of the coolant
ports with all others plugged, and check for leakage by
applying a soap solution to the exterior of the body. If
leakage is detected, replace the compressor.