Specifications

ManualsBrandsBENDIX ManualsAir CompressorTU-FLO 501 AIR COMPRESSOR

TU-FLO

501 AIR COMPRESSOR

SD-01-337*

DESCRIPTION AND OPERATION

General

The function of the air compressor is to provide and maintain

air under pressure to operate devices in the air brake and/

or auxiliary air systems.

Description

The Tu-Flo 501 is a two cylinder, single stage, reciprocating

compressor with a rated displacement of 12 cubic feet of

air per minute at 1250 R.P.M.

The Tu-Flo 501 is constructed from two major assemblies,

the head and the crankcase. The head houses the discharge

valving and is installed on the upper portion of the crankcase.

The crankcase is a one piece casting combining the cylinder

block and the crankcase. The upper portion of the casting

houses the cylinder bores and inlet valving; and the lower

portion, the crankshaft and main bearings. Various mounting

and drive configurations, required by the numerous vehicle

engine designs, are obtained by bolting different mounting

flanges, end covers, and base adapters to the crankcase.

Two horizontal governor mounting pads are located on either

side of the upper portion of the crankcase to provide

convenient governor mounting.

Two methods are employed for cooling the Tu-Flo 501 during

operation. The cylinder head is connected to the engine’s

cooling system, while the cylinder bore portion of the

crankcase has external fins for efficient air cooling.

*Formerly SD-01-3

Summary of content (13 pages)

PAGE 1
SD-01-337* ® TU-FLO® 501 AIR COMPRESSOR *Formerly SD-01-3 DESCRIPTION AND OPERATION General The function of the air compressor is to provide and maintain air under pressure to operate devices in the air brake and/ or auxiliary air systems. Description The Tu-Flo 501 is a two cylinder, single stage, reciprocating compressor with a rated displacement of 12 cubic feet of air per minute at 1250 R.P.M. The Tu-Flo 501 is constructed from two major assemblies, the head and the crankcase.
PAGE 2
D-1 D-2 D-3 FIGURE 1 - VARIOUS COMPRESSOR MOUNTINGS All Tu-Flo 501 compressors utilize the engine’s pressurized oil system to lubricate the internal moving parts. A nameplate is attached to the crankcase to identify the compressor. The nameplate displays a Bendix piece number or in some cases an engine or vehicle manufacturer’s piece number, along with a serial number. open inlet valve and into the cylinder (see Fig. 3).
PAGE 3
Lubrication TO RESERVOIR INLET VALVE DISCHARGE VALVE UNLOADER PLUNGER INTAKE STRAINER PISTON TO GOVERNOR STROKE Since all Tu-Flo 501 Compressors are connected to the engine’s pressurized oil system, a continuous flow of oil is provided to the compressor, which is eventually returned to the engine. Oil is fed into the compressor in various ways, for example: through the rear end cover, the drive end of the crankshaft or through the front flange adapter.
PAGE 4
discharge line must be cleaned or replaced and the compressor checked more thoroughly, paying special attention to the air induction system, oil supply and return system, and proper cooling. If necessary, repair or replace the compressor. Check for proper belt and pulley alignment and belt tension. Adjust if necessary, paying special attention not to over tighten the belt tension. Check for noisy compressor operation, which could indicate a worn drive gear coupling or a loose pulley.
PAGE 5
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.
PAGE 6
Connecting Rod Assemblies (Note: Before removing the connecting rods, mark each connecting rod and its cap. Each connecting rod is matched to its own cap for proper bearing fit, and these parts must not be interchanged.) 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.
PAGE 7
On compressors fitted with precision, sleeve main bearings, the difference between the O.D. of the crankshaft journal and the main bearing I.D. must not exceed .0065 in. If the clearance is greater than .0065 in., the end cover or main bearing must be replaced. Check the unloader bore bushings to be sure they are not worn, rusted, or damaged. If these bushings are to be replaced, they can be removed by running a 1/8 in. pipe thread tap into the bushing, and inserting a 1/8 in.
PAGE 8
If the compressor uses a ball type main bearing, press the ball bearing onto the correct end of the crankshaft. Position the ball bearing and the crankshaft in the crankcase, making sure the drive end of the crankshaft is positioned in the crankcase as marked before disassembly. Carefully press the crankshaft and ball bearing into the crankcase using an arbor press.
PAGE 9
Note: For cast iron flange adapters, torque the four 7/16 in. cap screws to 38-45 foot pounds. For die cast aluminum end covers, torque the four 7/16 in. cap screws to 25-30 foot pounds. All end covers using 5/16 in. cap screws or stud and nuts are torqued to 15-18 foot pounds. For through drive compressors with a cast iron end cover, torque the four 7/16 in. cap screws to 25-30 foot pounds.
PAGE 10
INSPECTION OF REBUILT UNIT Check to be sure that covers, plugs, or masking tape are used to protect all ports if compressor is not to be installed immediately. Fit the end of all crankshafts with keys, nuts, and cotter pins as required and then protect the ends against damage by wrapping with masking tape or friction tape. The open bottom of a vertical engine lubricated compressors should be protected against the entrance of dirt during handling or storage, by installing a temporary cover over the base.
PAGE 11
SYMPTOMS 2. Noisy compressor operation. CAUSE C. Poorly filtered inlet air. C. D. Insufficient compressor cooling (compressor runs hot). D. E. Contaminants not being regularly drained from system reservoirs. E. F. F. Compressor runs loaded an excessive amount of time. G. Excessive engine crankcase pressure. G. H. Excessive engine oil pressure. H. I. I. Faulty compressor. A. Loose drive gear or pulley. A. REMEDY mating engine surfaces are unobstructed and aligned.
PAGE 12
SYMPTOMS 3. Excessive build-up and recovery time. Compressor should be capable of building air system from 85-100 psi in 40 seconds with engine at full governed rpm. Minimum compressor performance is certified to meet Federal requirements by the vehicle manufacturer. Do not downsize the original equipment compressor. CAUSE B. Excessively worn drive couplings or gears. B. C. Compressor cylinder head or discharge line restrictions. C. D. Worn or burned out bearings. D. E. Faulty compressor. E. A.
PAGE 13
SYMPTOMS 4. 5. CAUSE Compressor fails to unload. Compressor leaks oil. 6. Compressor constantly cycles (compressor remains unloaded for a very short time.) G. Faulty compressor. G. A. Faulty governor or governor installation. A. B. Faulty or worn unloader pistons or bores. B. A. Damaged mounting gasket. A. B. Cracked crankcase, cylinder block or end cover. B. C. Loose end cover or cylinder block cap screws. D. Loose oil supply or return line fittings. E. Porous compressor casting. F.