SD-01-326 ® Bendix® TU-FLO® 400, 500, 1000 Air Compressors TU-FLO® 400 Air Compressor TU-FLO® 500 Air Compressor TU-FLO® 1000 Air Compressor 1
DESCRIPTION AND OPERATION GENERAL The function of the air compressor is to build up and maintain the air pressure required to operate air powered devices in air brake or air auxiliary systems. and they have no external moving parts. Both air and water cooled type compressors are available. Various mounting and drive adaptations are used as required by different vehicle engine designs (Fig. 4). DESCRIPTION Tu-Flo® Type 400, 500, and 1000 compressors are single stage, reciprocating piston type compressors.
OPERATION GENERAL FIGURE 5 ENGINE LUBRICATED TYPE FIGURE 6 SELF-LUBRICATED TYPE had either die cast aluminum, cast ductile iron, or forged steel rods which were not rifle drilled but were drilled at the top of the rod. The wrist pins and bushings are lubricated by oil dripping from a drip-boss on the piston into a “catch-funnel” at the top of the rod and through the drilled passage to the bushings and pins. (SEE FIG.
As the piston reaches the top of its stroke and starts down, the discharge valve spring returns the discharge valve to its seat. This prevents the compressed air in the discharge line from returning to the cylinder bore as the intake and compression cycle is repeated.
The Air Brake Charging System supplies the Discharge Line Optional “Ping” Tank Air Dryer compressed air for the braking system as well as other air accessories for the vehicle. The system usually consists of an air compressor, governor, discharge line, air dryer, and service reservoir.
FIGURE 16 - COMPRESSOR INTAKE ADAPTER FIGURE 14 - POLYURETHANE SPONGE STRAINER 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, carefully listen for escaping air at the intake.
Prelubricate compressor cylinder walls and bearings with clean engine oil before assembling compressor. Always use a new mounting gasket and be sure oil hole in gasket and compressor is properly aligned with oil supply line. SELF-LUBRICATED TYPES Fill compressor crankcase with clean engine oil before operating compressor. Refer to “Tabulated Data” section for proper amount. ALL TYPES Inspect pulley or gear and associated parts for wear or damage. They must be a neat fit on compressor crankshaft.
FIGURE 17 - TU-FLO® 400 AIR COMPRESSOR VERTICAL MOUNT - ENGINE LUBRICATED Straighten the prongs of the connecting rod bolt lock strap and remove the bolts and bearing caps. Push the piston with the connecting rods attached out the top of the cylinders of the crankcase. Replace the bearing caps on their respective connecting rods. Remove the piston rings from the pistons.
Press the crankshaft and ball bearings from the crankcase, then press ball bearings from crankshaft. Many compressors will have sleeve-type bearings in the crankcase or in the end cover. If the clearance between crankshaft journal and bearing exceeds .0065 in. the sleeve bearing should be replaced with appropriate undersize. CLEANING AND INSPECTION OF PARTS CLEANING All parts should be cleaned thoroughly in a good cleaning solvent before inspection.
CRANKCASE AND END COVERS Check for cracks or broken lugs in crankcase and end covers. Also check their oil passages to make sure they are open and clean. If an oil seal ring is used in the end cover, check fit of ring in ring groove. There should be 0.008 in. to 0.015 in. clearance at the gap when placed in the end bore of the crankshaft. If the oil ring is worn thin or is damaged, it should be replaced.
TU-FLO® 400 AIR COMPRESSOR CORRECT GROOVE CLEARANCE Used unloader mechanism should be replaced by unloader kits 265014 for Type Tu-Flo® 400 compressors and 265015 for Types Tu-Flo® 500 and 1000 compressors. The Tu-Flo® 1000 compressor requires two kits per compressor. .0015” .0030” The new unloader pistons should be a loose sliding fit in the unloader piston bores of the cylinder block. CORRECT GAP CLEARANCE WITH RING IN CYLINDER PARTS SPECIAL TO SELF-LUBRICATED TYPE COMPRESSORS .0035” .
Slightly worn or scratched inlet valves can be reclaimed by lapping them on a piece of fine crocus cloth on a flat surface, but it is suggested that new inlet valves be installed. ASSEMBLY INSTALLING CYLINDER BLOCK Position cylinder block gasket and block on crankcase according to markings made prior to disassembly. Using cap screws with lock washers, secure cylinder block to crankcase. Remove connecting bolts and bearing cap from one connecting rod.
BASEPLATE TESTING REBUILT COMPRESSOR SELF-LUBRICATED TYPE COMPRESSORS Install oil pump piston and rod on crankshaft. 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. Oil rod bearing fit must be the same as specified for connecting rod bearings.
3. Do not attempt to install, remove, disassemble or assemble a component until you have read and thoroughly understand the recommended procedures. Use only the proper tools and observe all precautions pertaining to use of those tools. 4. If the work is being performed on the vehicle’s air brake system, or any auxiliary pressurized air systems, make certain to drain the air pressure from all reservoirs before beginning ANY work on the vehicle.
MAINTENANCE INSTRUCTIONS FOR LARGE SUMP TU-FLO® 1000 AIR COMPRESSOR 288578 (SPECIAL APPLICATION) This compressor is an air-cooled, belt driven, self lubricated, V-four cylinder compressor. It is driven by an electric motor and cooling air is supplied by a fan on the driven pulley. The system air pressure is controlled between 135 psi and 150 psi by a pressure switch starting and stopping the electric motor.
40 BW1420 © 2004 Bendix Commercial Vehicle Systems LLC All rights reserved. 10/2004 Printed in U.S.A.
