Inlet Valves And Seats; Assembly; Installing Crankshaft; Pistons And Connecting Rods - BENDIX TU-FLO 750 COMPRESSOR Manual

INLET VALVES AND SEATS

Inlet valves and springs should be replaced. However, if the
inlet valve seats show signs of slight nicks or scratches,
they can be redressed with a fine piece of emery cloth or by
lapping with a lapping stone, grinding compound and grind-
ing tool. If the seats are damaged to the extent that they
cannot be reclaimed, they must be replaced.

ASSEMBLY

General Note: All torques specified in this manual are as-
sembly torques and typically can be expected to fall off
after assembly is accomplished. Do not retorque after ini-
tial assembly torques fall unless instructed otherwise. A
compiled listing of torque specifications is presented at the
end of this manual.
To convert inch pounds of torque to foot pounds of torque,
divide inch pounds by 12.
inch pounds ÷ 12 = foot pounds
To convert foot pounds of torque to inch pounds of torque,
multiply foot pounds by 12.
foot pounds x 12 = inch pounds

INSTALLING CRANKSHAFT

Press new sleeve bearings in the end cover and crankcase.
Ensure that the slot in the bearings line up with the oil pas-
sages in the end cover or crankcase. If you have a model
with no oil passage present in the crankcase, press the
sleeve bearing into the crankcase with the slot located 90
degrees from vertical.
Install the front thrust washer with the tang inserted in
the slot toward the flange. Insert the crankshaft and the
rear thrust washer with the tang toward the rear of the
compressor.
Place the oil seal ring on the boss of the rear end cover and
install the end cover making sure not to pinch the seal ring.
Ensure the tang of the thrust washer is inserted in the slot
of the end cover. Fasten the end cover to the crankcase with
the four cover cap screws. Torque the cap screws to 175-
225 inch pounds in a cross pattern.

PISTONS AND CONNECTING RODS

If the pistons are to be replaced ensure that the correct
pistons are being installed. Note that the pistons for the
®
Tu-Flo 750 compressor are similar to those of other Bendix
compressor models but may be identified by the piston
diameter and the distance to the center of the wrist pin from
the top of the piston as shown in Figure 13.
12
PISTON RINGS
Check each ring end gap in a cylinder bore before installa-
tion. Place the ring in the top of the cylinder bore and using
the piston, push the ring to the midpoint of the cylinder bore
and check the ring gap. If the end gaps are incorrect either
the wrong repair size has been purchased or the compres-
sor is worn beyond specification and should be replaced.
PISTON COMPARISON
1.25
®
OTHER BENDIX
TU-FLO ® AIR COMPRESSORS
FIGURE 13 - PISTON COMPARISON
Install the rings on the pistons per the following instructions
starting at the center of the piston and moving outward.
1. Install the spacer and segment rings as follows. Place
the spacer ring (25) in the piston groove, the ends of the
spacer must butt and not overlap. Install the top seg-
ment (24) by inserting one end above the spacer in the
ring groove, 120 degrees from the spacer ends and wind
the segment into position. Install the bottom segment in
the same manner beneath the spacer, making sure the
gap is staggered 120 degrees from both the top ring
segment and the spacer end gaps. Before using be sure
both painted ends of the spacer are visible and butted.
(Refer to Figure 14.)
FIGURE 14 - PISTON & RINGS
2.78
1.06
2.17
®
TU-FLO 750
AIR COMPRESSOR
COMPRESSION RING (23)
SEGMENT RING (24)
SPACER RING (25)
SEGMENT RING (24)