SD-01-670 ® Bendix® DuraFlo™ 596 Air Compressor DISCHARGE VALVE DISCHARGE VALVE HOLDER CYLINDER HEAD CYLINDER HEAD VALVE BODY ASSY.
DETROIT DIESEL CATERPILLAR FIGURE 2 - TYPICAL COMPRESSOR DRIVE FLANGES assembly using two cap screws and the cylinder head is secured to the cylinder block with six cap screws. The cylinder head, with the valve body halves comprise a complete cylinder head assembly. reduces compressor power consumption by approximately 80% in the unloaded mode. The ESS also reduces compressor oil consumption (oil passing) when the compressor is in the unloaded mode.
AIR INLET PORT AIR DISCHARGE PORT INLET CHECK VALVE OPEN NON-COMPRESSION OF AIR (UNLOADED) ESS CHAMBER INLET VALVE OPEN DISCHARGE VALVE CLOSED UNLOADER PISTON PISTON MOVING DOWN FIGURE 4 - OPERATIONAL-LOADED (INTAKE) AIR INTAKE (LOADED) The piston strokes are 180 degrees opposed. As one piston is on an up stroke the opposing piston is on a down stroke. During the piston down stroke, a vacuum is created in the cylinder and ESS chamber within the cylinder head.
air dryer is not used to remove these contaminants prior to entering the air system, the majority, but not all, will condense in the reservoirs. The quantity of contaminants that reach the air system depends on several factors including installation, maintenance and contaminant handling devices in the system. These contaminants must either be eliminated prior to entering the air system or after they enter. DISCHARGE INLET PORTS VALVE DISCHARGE PORTS DUTY CYCLE CYLINDER HEAD SIDE OF VALVE BODY ASSY.
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.
AIR INDUCTION The DuraFlo 596 compressor is approved for natural aspiration only. The compressor inlet is connected to the vacuum side of the engine air induction system. See the tabulated technical data in the back of this manual for specific requirements. ™ PREVENTATIVE MAINTENANCE Regularly scheduled maintenance is the single most important factor in maintaining the air brake charging system.
COMPRESSOR DRIVE Check for noisy compressor operation, which could indicate excessive drive component wear. Adjust and/or replace as necessary. Check all compressor mounting bolts and retighten evenly if necessary. Check for leakage and proper unloader mechanism operation. Repair or replace parts as necessary. COMPRESSOR & GOVERNOR UNLOADER SYSTEM Test and inspect the compressor and governor unloader system for proper operation and pressure setting. 1.
26 1 9 9 2 10 10 11 12 11 25 12 CYLINDER HEAD VALVE BODY ASSY. 7 6 5 7 6 5 4 13 4 14 3 15 16 8 3 17 18 41 CRANKCASE & CYLINDER BLOCK 23 19 21 20 24 22 31 FLANGE MOUNT 27 END COVER 30 29 28 Item Qty. 1 6 2 2 3 2 4 2 5 2 6 2 7 2 8 1 9 4 10 4 11 2 Description 13mm x 85mm Bolt 13mm x 60mm Bolt 10mm x 25mm Bolt Spacer Sleeve Holder Inlet Check Valve Seat Head to Vlv. Assy. Gskt. 10mm x 25mm Bolt Spacer Sleeve Holder Item Qty.
1. With the engine running, lower air system pressure to 90 psi and raise engine RPM to 1800. Measure and record the time required to raise system pressure from 100 psi to 130 psi. Run this test three times and use the average time. WARNING! PLEASE READ AND FOLLOW THESE INSTRUCTIONS TO AVOID PERSONAL INJURY OR DEATH: Note: This test should be run with the engine and air system at normal operating temperature (i.e. not cold). 1.
REMOVAL UNLOADER & INLET VALVE These instructions are general and are intended to be a guide. In some cases additional preparations and precautions are necessary. In all cases follow the instructions contained in the vehicle maintenance manual in lieu of the instructions, precautions and procedures presented in this manual. 1. Remove the discharge safety valve (26) from the cylinder head. 1. Block the wheels of the vehicle and drain the air pressure from all the reservoirs in the system. 4.
5. Remove the two 10mm x 25mm discharge valve bolts (9) that secure the discharge check valve components. Remove the spacer sleeve (10), holder (11) and discharge valve (12). OIL PASSAGES 6. Repeat step 5 for the second discharge valve assembly. Thoroughly clean all oil passages through the end cover or end cover adapter. Inspect the passages with a wire to be sure. Blow the loosened foreign matter out with air pressure. CRANKCASE COVER CYLINDER BLOCK UNLOADER BORES 1.
ASSEMBLY 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 re-torque after initial assembly torques fall unless instructed otherwise. A compiled listing of torque specifications is presented at the end of this manual. INCH POUNDS TO FOOT POUNDS To convert inch pounds to foot pounds of torque, divide inch pounds by 12.
certain the free tip of the discharge valve (12) is not pinched between the holder (11) and the valve body assembly. The valve must be free to flex. 4. Torque the 10mm bolts to 101 to 111 inch pounds. 5. Repeat steps one through four for the other discharge valve assembly. UNLOADER PLUNGERS 1. Install the metal sealing washer (20) on the plug (19) and set aside. 4. Locate one of the sliding inlet valves (13) and place it on a flat surface.
7. Torque the two 13mm x 60mm head bolts to 265 - 292 inch pounds. 8. Beginning with one of the center bolts, torque the six 13mm x 85mm head bolts to 265 - 292 inch pounds using a figure eight pattern. 9. Apply a thread sealant to the assembled plug and sealing washer (19 & 20) and install it in the cylinder block unloader bore that was marked during disassembly. Tighten sufficiently to seal air pressure. INSTALLING THE COMPRESSOR 1.
DIMENSIONAL DATA Port Sizes Metric (Detroit Diesel) Water inlet ......................................................... M16 x1.5 Water outlet ....................................................... M16 x1.5 Discharge Safety Valve ....................................... M16 x1.5 Air discharge ......................................................... M27 x2 Unloader Port ..................................................... M22 x1.5 Oil inlet (end cover or adapter) ............................ M12 x1.5 U.S.
This troubleshooting guide obsoletes and supersedes all previous published troubleshooting information relative to Bendix air compressors. Advanced Troubleshooting Guide for Air Brake Compressors * The guide consists of an introduction to air brake charging system components, a table showing recommended vehicle maintenance schedules, and a troubleshooting symptom and remedy section with tests to diagnose most charging system problems.
Introduction to the Air Brake Charging System Powered by the vehicle engine, the air compressor builds the air pressure for the air brake system. The air compressor is typically cooled by the engine coolant system and lubricated by the engine oil supply.
Table A: Maintenance Schedule and Usage Guidelines Regularly scheduled maintenance is the single most important factor in maintaining the air brake charging system. Vehicle Used for: No. of Axles Column 1 Column 2 Typical Compressors Spec'd Discharge Line I.D. Length 1/2 in. 6 ft. Column 3 Recommended Air Dryer Cartridge Replacement1 Column 4 Recommended Reservoir Drain Schedule2 Column 5 Acceptable Reservoir Oil Contents3 at Regular Drain Interval e.g.
Air Brake Charging System Troubleshooting How to use this guide: Find the symptom(s) that you see, then move to the right to find the possible causes (“What it may indicate”) and remedies (“What you should do”). Review the warranty policy before performing any intrusive compressor maintenance. Unloader or cylinder head gasket replacement and resealing of the bottom cover plate are usually permitted under warranty. Follow all standard safety procedures when performing any maintenance.
Symptom: What it may indicate: What you should do: 2.0 Oil on the Outside of the Compressor Engine and/or other accessories leaking onto compressor. Find the source and repair. Return the vehicle to service. 2.1 Oil leaking at compressor / engine connections: (a)Leak at the front or rear (fuel pump, etc.) mounting flange. ð Repair or replace as necessary. If the mounting bolt torques are low, replace the gasket. (b)Leak at air inlet fitting. ð Replace the fitting gasket.
Symptom: What it may indicate: 4.0 Oil in Supply or Service Reservoir (air dryer installed) What you should do: Maintenance (a) If air brake charging system maintenance has not been (If a maintained Bendix performed.
Symptom: What it may indicate: 4.0 Oil in Supply or Service Reservoir* (air dryer installed) (continued) What you should do: Temperature (e) Air compressor discharge and/or air dryer inlet temperature too high. ð Check temperature as outlined in Test 3 on page 29. If temperatures are normal go to 4.0(h). (f) Insufficient coolant flow. ð Inspect coolant line. Replace as necessary (I.D. is 1/2"). ð Inspect the coolant lines for kinks and restrictions and fittings for restrictions. Replace as necessary.
Symptom: 4.0 Oil in Supply or Service Reservoir* (air dryer installed) (continued) What it may indicate: What you should do: Other (cont.) (i) Poorly filtered inlet air (poor air quality to compressor). Inspect the engine air cleaner. ð Check for leaking, damaged or defective compressor air inlet components (e.g. induction line, fittings, gaskets, filter bodies, etc.). Repair inlet components as needed. Note: Dirt ingestion will damage compressor and is not covered under warranty.
Symptom: What it may indicate: What you should do: 6.0 Excessive oil consumption in engine. A problem with engine or other engine accessory. ð See engine service manual. 7.0 Oil present at air dryer cartridge during maintenance. Air brake charging system is functioning normally. The engine service manual has more information. Oil shown leaking from an air dryer cartridge. 24 ð Air dryers remove water and oil from the air brake charging system. A small amount of oil is normal.
Symptom: 9.0 Air brake charging system seems slow to build pressure. (continued) What it may indicate: What you should do: (f) Restricted discharge line. ð If discharge line is restricted: ð By more than 1/16" carbon build up, replace the discharge line (see Table A, column 2, on page 18 for recommended size) and go to Test 3 on page 29. ð By other restrictions (e.g. kinks). Replace the discharge line. See Table A, column 2, on page 18 for recommended size. Retest for air build.
Symptom: 10.0 Air charging system doesn’t build air. What it may indicate: (a) Governor malfunction*. ð Go to Test 4 on page 30. (b) Restricted discharge line. ð See 9.0(f). (c) Air dryer heater malfunction: exhaust port frozen open. ð Replace air dryer heater. (d) Compressor malfunction. ð Replace the compressor only after making certain the preceding conditions do not exist.
Symptom: 12.0 Air dryer safety valve releases air. What it may indicate: What you should do: (a) Restriction between air dryer and reservoir. ð Inspect delivery lines to reservoir for restrictions and repair as needed. (b) Air dryer safety valve malfunction. ð Verify relief pressure is at vehicle or component manufacturer specifications. Replace if defective. (c) Air dryer performed. ð See Maintenance Schedule and Usage Guidelines (Table A, column 3, on page 18).
Symptom: 16.0 Compressor leaks air What it may indicate: (a) Compressor leaks connections or ports. at ð Check for leaking, damaged or defective compressor fittings, gaskets, etc. Repair or replace as necessary. ð Go to Test 6 on page 30. (c) Damaged gasket. head ð An air leak at the head gasket may indicate a downstream restriction such as a freezeup or carbon blockage and/or could indicate a defective or missing safety valve. Find blockage (go to 9.0(f) for details.) and then replace the compressor.
Tests Test 1: Excessive Oil Leakage at the Head Gasket Exterior leaks at the head gasket are not a sign that oil is being passed into the air charging system. Oil weepage at the head gasket does not prevent the compressor from building air. Observe the amount of weepage from the head gasket. If the oil is only around the cylinder head area, it is acceptable (return the vehicle to service), but, if the oil weepage extends down to the nameplate area of the compressor, the gasket can be replaced.
Tests (continued) Test 4: Governor Malfunction 1. Inspect control lines to and from the governor for restrictions (e.g. collapsed or kinked). Repair as necessary. 2. Using a calibrated external gauge in the supply reservoir, service reservoir, or reservoir port of the D-2™ governor, verify cut-in and cutout pressures are within vehicle OEM specification. 3. If the governor is malfunctioning, replace it. Test 5: Governor Control Line 1.
NOTES 31
Appendix A: Information about the BASIC™ Test Kit (Bendix P/N 5013711) Service writer records info - including the number of days since all air tanks were drained - and fills out symptom checklist. Technician inspects items. days Bendix® Air System Inspection Cup (BASIC™) Test Information START BASIC TEST Park vehicle on LEVEL ground. Chock wheels, drain air from system. Drain contents of ALL air ™ tanks into BASIC cup Is there less than one unit of liquid? Vehicle OK. Return vehicle to service.
Appendix A continued: Information about the BASIC™ Test Kit (Bendix P/N 5013711) ® Filling in the Checklist for the Bendix Air System Inspection Cup (BASIC™) Test Note: Follow all standard safety precautions. For vehicles using a desiccant air dryer.
Appendix A continued: Information about the BASIC™ Test Kit (Bendix P/N 5013711) ® Filling in the Checklist for the Bendix Air System Inspection Cup (BASIC™) Test Note: Follow all standard safety precautions. For vehicles using a desiccant air dryer. 2. Record amount of oil found: The Technician uses the chart (label) on the BASIC™ test cup to help decide the action to take, based on the amount of oil found.
Appendix B Technical Bulletin Bulletin No.: TCH-008-021 Subject: Effective Date: 11/1/92 Page: 1 of 2 Air Brake System - Cold Weather Operation Tips As the cold weather approaches, operators and fleets alike begin to look to their vehicles with an eye toward “winterization”, and particularly what can be done to guard against air system freeze-up. Here are some basic “Tips” for operation in the cold weather.
Appendix B: Continued Bulletin No.: TCH-008-021 Effective Date: 11/1/92 Page: 2 of 2 High Duty Cycle Vehicles (City Transit Coaches, Refuse Haulers, Etc.) The maximum discharge line length is 16 feet. Length I.D. min. Other Requirements 10-16 ft. ½ in. None If the discharge line length must be less than 10 feet or greater than 16 feet, contact your local Bendix representative.
Appendix B: Continued Technical Bulletin Bulletin No.: TCH-008-022 Subject: Additional Effective Date: 1/1/1994 Page: 1 of 1 Cold Weather Operation Tips for the Air Brake System Last year we published Bulletin PRO-08-21 which provided some guidelines for “winterizing” a vehicle air brake system. Here are some additional suggestions for making cold weather vehicle operation just a little more bearable.
BW1845 © 2004 Bendix Commercial Vehicle Systems LLC. All rights reserved. 10/2004 Printed in U.S.A.
