SD-01-670 Š Bendix® DuraFlo 596™ Air Compressor DISCHARGE VALVE DISCHARGE VALVE HOLDER WATER INLET PORT (2) CYLINDER HEAD CYLINDER HEAD VALVE BODY ASSEMBLY WATER OUTLET PORT (1) VALVE BODY ASSEMBLY UNLOADER PORT PISTON PISTON RINGS CRANKCASE CRANKSHAFT DISCHARGE SAFETY VALVE REAR END COVER OIL PORT CRANKCASE CRANKCASE BOTTOM COVER (2) CONNECTING ROD DISCHARGE CAVITY DESCRIPTION The function of the air compressor is to provide and maintain air under pressure to operate devices in the air br
The DuraFlo 596™ compressor incorporates an unloader system that features an energy saving system or ESS which 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. A nameplate identifying the compressor piece number and serial number is attached to the end of the cylinder block opposite the drive end.
AIR INLET PORT AIR DISCHARGE PORT INLET CHECK VALVE OPEN AIR INLET PORT INLET CHECK VALVE CLOSED AIR DISCHARGE PORT ESS CHAMBER ESS CHAMBER INLET VALVE OPEN DISCHARGE VALVE CLOSED INLET VALVE OPEN DISCHARGE VALVE CLOSED UNLOADER PISTON PISTON MOVING UP & DOWN PISTON MOVING DOWN UNLOADER PISTON & PIVOT ARM SLIDES INLET VALVE OVER FIGURE 6 - OPERATIONAL-UNLOADED FIGURE 4 - OPERATIONAL-LOADED (INTAKE) AIR COMPRESSION (LOADED) When the piston reaches approximately bottom dead center (BDC) the in
DISCHARGE VALVE 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.
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.
PREVENTATIVE MAINTENANCE Regularly scheduled maintenance is the single most important factor in maintaining the air brake charging system. Refer to Table A in the Troubleshooting section for a guide to various considerations that must be given to the maintenance of the compressor and other related charging system components. Important Note: Review the warranty policy before performing any intrusive maintenance procedures.
COMPRESSOR & GOVERNOR UNLOADER SYSTEM Test and inspect the compressor and governor unloader system for proper operation and pressure setting. 1. Make certain the unloader system contains both the governor and synchro valve as illustrated in Figure 3. 2. Cycle the compressor through the loaded and unloaded cycle several times. Make certain that the governor cuts out at 130 psi (cut-in should be approximately 110 psi). Adjust or replace the governor as required. 3.
1 9 9 2 26 10 10 11 12 11 25 12 CYLINDER HEAD VALVE BODY ASSEMBLY 7 6 5 7 6 5 4 13 4 14 3 15 16 8 3 17 18 CRANKCASE & CYLINDER BLOCK 23 19 21 20 24 22 31 27 FLANGE MOUNT COMPRESSOR END COVER 30 29 28 Item 1 2 3 4 5 6 7 8 9 10 11 Qty. 6 2 2 2 2 2 2 1 4 4 2 Description 13mm x 85mm Bolt 13mm x 60mm Bolt 10mm x 25mm Bolt Spacer Sleeve Holder Inlet Check Valve Seat Head to Valve Asm. Gskt. 10mm x 25mm Bolt Spacer Sleeve Holder Item 12 13 14 15 16 17 18 19 20 21 22 Qty.
Unloader leakage is exhibited by excessive compressor cycling between the loaded and unloaded condition. 1. With service and supply system leakage below the maximum allowable limits and the vehicle parked, bring system pressure to governor cut-out and allow the engine to idle. 2. The compressor should remain unloaded for a minimum of 5-10 minutes.
REMOVAL 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. Block the wheels of the vehicle and drain the air pressure from all the reservoirs in the system. 2. Drain the engine cooling system and the cylinder head of the compressor.
4. Repeat step 3 for the second inlet check valve assembly. 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). 6. Repeat step 5 for the second discharge valve assembly. CRANKCASE COVER 1. Remove the four cap screws (28) securing the crankcase cover (29). Using a soft mallet, gently tap the crankcase cover (29) to break the gasket seal.
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.
Before attempting to tighten the two 10mm bolts make 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. Pivot Arm Stud Valve Body Inlet Valve Pivot Arm Concave Area 5. Repeat steps one through four for the other discharge valve assembly. Cylinder Block UNLOADER PLUNGERS FIGURE 12 - SLIDING INLET VALVE INSTALLATION 1.
plunger bore and depress the plunger (21) several times. The plunger (21) should move freely with only spring tension resistance noted. If greater resistance is noted the sliding inlet valve (13) is pinched and the cylinder head and valve body must be removed and the sliding inlet valve (13) must be repositioned within the opening of the meatal gasket (18). Repeat this procedure for the other unloader plunger and sliding inlet valve. 7. Torque the two 13mm x 60mm head bolts to 265 - 292 inch pounds. 8.
TORQUE SPECIFICATIONS Assembly torques in inch pounds (in. Ibs.) 13mm Cylinder head bolts ................................. 265 - 292 10mm Valve bolts ................................................101 -111 Rear end cover or adapter bolts/studs ............. 195 - 212 Bottom cover ..................................................... 97 - 115 Crankshaft nut ............................................. 1200 - 1440 Metric (Detroit Diesel) M12 x 1.5 ...........................................................
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. Column 1 Vehicle Used for: Typical Compressors No. of Spec'd Axles Column 2 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. Repair or replace as necessary. If the mounting bolt torques are low, replace the gasket. (b)Leak at air inlet fitting. Replace the fitting gasket.
Symptom: What it may indicate: 4.0 Oil in Supply or Service Reservoir (air dryer installed) ® (If a maintained Bendix PuraGuard® system filter or Bendix® PuraGuard® QC oil coalescing filter is installed, call 1-800-AIR-BRAKE (1-800-247-2725) and speak to a Tech Team member.) What you should do: Maintenance (a) If air brake charging system maintenance has not been 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. Check temperature as outlined in Test 3 on page 29. If temperatures are normal go to 4.0(h). (f) Insufficient coolant flow. Inspect coolant line. Replace as necessary (I.D. is 1/2"). 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). 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. Inspect the engine air cleaner.
Symptom: What it may indicate: What you should do: 6.0 Excessive oil consumption in engine. A problem with engine or other engine accessory. 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 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. If discharge line is restricted: 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. 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*. Go to Test 4 on page 30. (b) Restricted discharge line. See 9.0(f). (c) Air dryer heater malfunction: exhaust port frozen open. Replace air dryer heater. (d) Compressor malfunction. 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. Inspect delivery lines to reservoir for restrictions and repair as needed. (b) Air dryer safety valve malfunction. Verify relief pressure is at vehicle or component manufacturer specifications. Replace if defective. (c) A i r d r y e r m a i n t e n a n c e n o t performed. See Maintenance Schedule and Usage Guidelines (Table A, column 3, on page 18).
Symptom: 16.0 Compressor leaks air Testing for leaks with soap solution. What it may indicate: What you should do: (a) C o m p r e s s o r l e a k s a i r a t connections or ports. Check for leaking, damaged or defective compressor fittings, gaskets, etc. Repair or replace as necessary. (b) Compressor unloader mechanism malfunction. Go to Test 6 on page 30. (c) Damaged compressor head gasket.
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 cut-out 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 1. Record days since air tanks were last drained. 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. Use the lower acceptance line for low air use vehicles, and upper line for high air use vehicles (from Step A).
Appendix B Technical Bulletin Bulletin No: TCH-008-021 Subject: Effective Date: 3-5-2010 Cancels: PRO-08-21 dated 2-6-2008 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: 3/5/2010 Page: 2 of 2 System Leakage Check the air brake system for excessive air leakage using the Bendix “Dual System Air Brake Test and Check List” (BW1279). Excessive system leakage causes the compressor to “pump” more air and also reduce the life of the air dryer desiccant cartridge. Reservoir Draining (System without an Air Dryer) Routine reservoir draining is the most basic step in reducing the possibility of freeze-up.
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 TCH-008-021 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 © 2010 Bendix Commercial Vehicle Systems LLC. All rights reserved. 03/2010 Printed in U.S.A.
