SD-01-3131 BENDIX® 720CC TWIN CYLINDER COMPRESSOR FOR INTERNATIONAL MAXXFORCE™ BIG BORE ENGINES Cylinder Head Safety Valve Cooling Plate Valve Plate Assembly Crankcase Right Side View Mounting Face Rear Flange Locating Pins FIGURE 1 - BENDIX® 720CC TWIN CYLINDER COMPRESSOR PRODUCT ® This Bendix 720cc twin cylinder compressor is a “discharge line unloader” (DLU)-style compressor.
Compressor to engine block mounting face Oil drain locations Safety Valve Cylinder Head Cooling Plate Piston Valve Plate Assembly Mounting Face Nameplate Crankcase Connecting Rod Drive Gear Crankshaft FIGURE 3 - BENDIX® 720CC TWIN CYLINDER COMPRESSOR gasket is installed between the valve plate assembly and the top of the crankcase. The cast iron crankcase has a water jacket to assist in the cooling of the cylinder bore. The crankcase has an open side with a machined face and locating pins.
Air Discharge Port Air Inlet Port Discharge Valve Closed Air Discharge Port Cooling Plate Air Inlet Port Discharge Valve Open Cooling Plate Valve Plate Valve Plate Inlet Valve Closed Inlet Valve Open Piston Moving Down Piston Moving Up FIGURE 4 - OPERATION - INTAKE FIGURE 5 - OPERATION - COMPRESSION OPERATION AIR COMPRESSION (LOADED) The compressor is driven by the vehicle's engine, and functions continuously while the engine is in operation.
Discharge Port Inlet Port Coolant Port (In or Out) Head Bolt (8) Safety Valve Port Coolant Port (In or Out) CYLINDER HEAD PORT IDENTIFICATION The cylinder head connection ports are identified with “cast in” numerals as follows: AIR IN . . . . . . . . . . . . . 0 Compressed AIR OUT . . . . . 2 Coolant IN . . . . . . . . . . . 9 Coolant Out . . . . . . . . . .
AIR INDUCTION ® The Bendix 720cc twin cylinder compressor is only permitted to be naturally aspirated – use of an engine turbocharger as an air source is not allowed. PREVENTATIVE MAINTENANCE Regularly scheduled maintenance is the single most important factor in maintaining the air brake charging system.
3. Note that the charging system cycles to the loaded and unloaded conditions promptly. If prompt action is not noted, repair or replace the governor and/or repair the air dryer purge valve assembly. IMPORTANT NOTE Replacement air governors must have a minimum cut-in pressure of 100 psi. The cut-in pressure is the lowest system pressure registered in the gauges before the compressor resumes compressing air.
leakage can generally be detected by longer compressor build-up and recovery times. Compare current compressor build-up times with the last several recorded times. Make certain to test for air system leakage, as described under “InService Operating Tests”, before making a determination that performance has been lost. COMPRESSOR REMOVAL & DISASSEMBLY 5.
3 4 1 2 Cylinder Head 5 Cooling Plate 6 Valve Plate Assembly 7 Crankcase Alignment Pins (x2) - one at each end 8 Crankcase 10 9 Cap Screws (x2) Compressor Drive Gear Crankcase Side Cover End Cover 11 Crankcase Side Cover Cap Screws (x6) Safety Valve Kit Pc. No. K026809 consists of the following: Item 1 2 Qty. Description 1 1 Sealing Ring ST-4™ Safety Valve Compressor Seal Kit (Minor) Pc. No. K051352 consists of the following: Item Qty.
4. Remove the discharge fitting, if applicable, and note their position on the compressor to aid in reassembly. 5. Remove any supporting bracketing attached to the compressor and note their positions on the compressor to aid in reassembly. 6. Remove the six (6) mounting bolts that retain the compressor to the side of the engine block. Note the position of the six mounting bolts. Two of the six bolts are shorter and must be installed in their original locations. Remove the compressor from the vehicle. 7.
CRANKCASE FRONT COVER 1. Remove the cover (9) from the front of the crankcase. Use a sharp flat head screw driver or a scraper. Place the edge under the lip along the outside diameter of the cover. Pry the cover from the cast surface until the cover can be removed. Refer to Figure 10. CRANKCASE SIDE COVER 1. Remove the six cap screws that secure the crankcase side cover to the crankcase. 2.
REAR END COVER Check for cracks and external damage. Check the crankshaft rear bearing diameter in the rear end cover for excessive wear, flat spots or galling. Check the hydraulic pump attachment pilot and threaded holes for damage. Minor thread chasing is permitted, but do not re-cut the threads. If any of these conditions are found, replace the compressor. CRANKCASE Check the cylinder head gasket surface on the deck (top) of the crankcase for nicks, gouges, and marring.
INSTALLING THE COMPRESSOR 3, 13 7, 17 1, 11 6, 16 10, 20 9, 19 5, 15 2, 12 4, 14 8, 18 Sequence Torque (In-lbs) Torque (Nm) 1 through 10 177 20 11 through 20 265-292 30-33 FIGURE 11 - CYLINDER HEAD BOLT TORQUE SEQUENCE Note: To assist with correct installation, the alignment bushings in the cooling plate only fit into two of the four corner head bolt holes on the valve plate assembly and the cylinder head. 7. Install the eight long hex head cap screws (3) into the cylinder head.
BENDIX® 720CC TWIN CYLINDER COMPRESSOR SPECIFICATIONS TORQUE SPECIFICATIONS Typical weight ...................................... 67 LBS (30.5 KG) M8x1.25-6g Cylinder Head Bolts ........... 265-292 In. Lbs. (30-33 Nm) Number of cylinders ....................................................... 2 Bore Diameter .................................... 3.622 IN (92 MM) Stroke ................................................. 2.126 IN (54 MM) Calculated displacement at 1250 RPM ............ 31.
Notes 14
Appendix A 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. INDEX Symptom Page Number Air Symptom Page Number Coolant Air brake charging system: Slow build (9.0) .....................................A-9-10 Doesn’t build air (10.0) .........................
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.
Air Brake Charging System Troubleshooting Look for: 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: 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 it may indicate: What you should do: Maintenance (a) If air brake charging system maintenance has not been performed.
Symptom: 4.0 Oil in Supply or Service Reservoir* (air dryer installed) (continued) What it may indicate: 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 A-14. If temperatures are normal go to 4.0(h). Inspect coolant line. Replace as necessary (I.D. is 1/2"). (f) Insufficient coolant flow. Inspect the coolant lines for kinks and restrictions and fittings for restrictions.
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. 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 A-3 for recommended size) and go to Test 3 on page A-14. By other restrictions (e.g. kinks). Replace the discharge line. See Table A, column 2, on page A-3 for recommended size. Re-test for air build.
Symptom: 10.0 Air charging system doesn’t build air. What it may indicate: What you should do: (a) Governor malfunction*. Go to Test 4 on page A-15. (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. Air dryer safety valve 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) Air dryer maintenance not performed.
Symptom: 16.0 Compressor leaks air (b) is not applicable for the compressor featured in this SD sheet —- information is shown for reference only. What you should do: (a) Compressor leaks air at 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 A-15. (c) Damaged compressor head gasket(s).
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. Look for Weepage Observe the amount of weepage from the head gasket.
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.
Appendix B: 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 B 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 B 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 C 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 C: 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 D 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.
Appendix E Application Matrix for Bendix® 360cc Single Cylinder and 720cc Twin Cylinder Compressors for International Maxxforce™ Big Bore Engines This useful Compressor Application Guide is a simple point system using vehicle configuration and vocation options to help calculate the Bendix® compressor right for your vehicle.
Appendix E Increasing Performance Compressor Application School Bus / RV / Air over Hydraulic Point Total 360cc Single any City Transit Bus / Highway Travel Coach / Express Route Coach any School Bus Rural Route (No Auto Brake) any School Bus City Route (No Auto Brake) any Pick-up & Delivery 720cc Dual 2.5 - 9 9.5 - 13 Line Haul 3-6 6.5 - 9 9.5 - 13 Rural or Commercial Refuse 6.5 - 9 Rural or Commercial Refuse / Yard or Terminal Jockey 9.
Appendix E Example #1: Typical Line Haul Application Vehicle Configuration 1. Not Applicable 2. Total number of all axles 3. Total number of non-steerable lift axles 4. Total number of steerable lift axles 5. Tractor is equipped with air suspension = = = = 3 0 0 .5 points points points point = 0 points Vocation Options 6, 7, 8, 9, 10, 11, 12 (Not Applicable) Total [ 3 + 0.5 = 3.
