Usage:
General Note:
All torques specified in this manual are assembly torques and typically can be expected to fall off after assembly is accomplished. DO NOT RETORQUE after initial assembly torques fall unless instructed otherwise. A compiled listing of torque specifications is presented in the Torque Specifications section of this manual. To convert inch pounds of torque to foot pounds of torque, divide in 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 × 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 passages 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 20 - 25 N·m (175 - 225 lb in) in a crossing 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 550 compressor are similar to those of other Bendix compressor models but may be identified by the piston diameter of 70.16 mm (2.780 in) and the distance to the center of the wrist pin from the top of the piston of 31.75 mm (1.250 in).
Piston Rings
Check each ring end gap in a cylinder bore before installation. Place the ring in the top of the cylinder bore and using the piston, push the ring to the mid-point 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 compressor is worn beyond specification and should be replaced.
Install the rings on the pistons per the following instructions starting at the center of the piston and moving outward.
Fig 14 Piston And Rings
1. Install the spacer and segment rings as follows:
Place spacer ring (25) in the piston groove, the ends of the spacer must butt and not overlap. Install top segment (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 Fig 14).
2. Install compression rings (23) in the proper grooves with the bevel or "pip" mark (if any) toward the top of the piston. (Refer to Fig 14).
Check the ring side clearance of each ring in the piston ring groove. (Refer to Fig 14). If the side clearance is too large, the piston ring groove is worn beyond specifications and the piston must be replaced.
Rotate the piston rings in their respective groove so that each end gap is at least 90 degrees from the previous ring's end gap.
Lubricate wrist pin (22) and wrist pin bushing in the connecting rod with engine oil. Assemble the upper portion of the connecting rods and the pistons with the wrist pins. Insert wrist pin buttons (28) in the ends of the wrist pin. Lubricate the pistons and rings with engine oil and insert the piston in the cylinder bore.
Turn the crankshaft so that one of its connecting rod journals is in the downward, center position. Install the crankshaft journal bearing segments(38) on connecting rod (37) and connecting rod cap (39). Tighten connecting rod bolts (40) evenly and torque to 17 to 19 N·m (150 to 170 lb in). Install the other connecting rod and piston in the same manner. It is recommended that new connecting rod cap screws be used.
Before replacing the cylinder head on the crankcase ensure the correct pistons have been used by turning the crankshaft one complete revolution such that each piston moves to its maximum upward stroke. At the maximum upward stroke position each piston should move to the top of the crankcase. If the piston does not approach the top of the crankcase the piston is incorrect and if not replaced could result in compressor damage.
Base Plate Or Base Adapter
Position base plate or base adapter gasket (20) on the crankcase and install the base plate or base adapter (21) as marked before disassembly. Tighten six cap screws (22) securing the cast iron base adapter evenly to a torque of 20 to 25 N·m (175 to 225 lb in) for base plate or cover in a crossing pattern after first snugging all six screws.
Cylinder Head
Place cylinder head gasket (19) and cylinder head on the compressor crankcase and install the six cylinder head cap screws. If the cylinder head gasket has a bead on one side, install the gasket on the crankcase with the beaded side up. Snug the cylinder head cap screws prior to torquing the cap screws to 50 to 57 N·m (440 to 500 lb in) in a cross pattern. Re-torque the unloader cover cap screws to 19 to 25 N·m (170 to 225 lb in).
Final Compressor Assembly
Install all crankshaft keys making certain to support the crankshaft to avoid bearing damage. Install the crankshaft nut where applicable. When installing drive couplings or gears, DO NOT EXCEED 160 N·m (120 lb ft) torque on the crankshaft nut.
Use covers, plugs, or masking tape to protect all ports if compressor is not to be installed immediately. Protect the ends of the crankshaft against damage by wrapping with masking tape or friction tape.
Testing Rebuilt Compressor
In order to properly test a compressor under operating conditions, a test rack for correct mounting, cooling, lubricating, and driving the compressor is necessary. Such tests are not compulsory if the unit has been carefully rebuilt by an experienced person. A compressor efficiency or build up test can be run which is not too difficult. An engine lubricated compressor must be connected to an oil supply line of at least 100 kPa (15 psi) pressure during the test and an oil return line must be installed to keep the crankcase drained.
Connect to the compressor discharge port, a reservoir with a volume of 1500 cubic inches, including the volume of the connecting line. With the compressor operating at 2100 rpm, the time required to raise the reservoir(s) pressure from 580 to 700 kPa (85 to 100 psi) should not exceed seven seconds. During this test, the compressor should be checked for gasket leakage and noisy operation, as well as unloader operation and leakage.
If the compressor functions as indicated re-install on the vehicle connecting all lines as marked in the disassembly procedure.