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.
GENERAL SAFETY GUIDELINES WARNING! PLEASE READ AND FOLLOW THESE INSTRUCTIONS TO AVOID PERSONAL INJURY OR DEATH: When working on or around a vehicle, the following guidelines should be observed AT ALL TIMES: ▲ Park the vehicle on a level surface, apply the parking brakes and always block the wheels. Always wear personal protection equipment. ▲ Stop the engine and remove the ignition key when working under or around the vehicle.
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 Crankshaft Drive Gear FIGURE 3 - BENDIX® 720CC TWIN CYLINDER COMPRESSOR are part of the valve plate assembly. The inlet reed valve/ 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.
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.
Inlet Port Discharge 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 LUBRICATION INSPECTION 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. The compressor utilizes an internal oil feed design. Check the exterior of the compressor (e.g. around the mounting face) for the presence of oil seepage, and refer to the troubleshooting section for appropriate tests and corrective action.
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.
INLET & DISCHARGE VALVES In order to test the inlet and discharge valves, it is necessary to have shop air pressure and an assortment of fittings. A soap solution is also required. 1. With the engine shut off, drain ALL air pressure from the vehicle. 2. Disconnect the inlet and discharge lines. 3. Apply 120-130 psi shop air pressure to the discharge port and then apply and release air pressure to the inlet port. Soap the inlet port and note that leakage at the inlet port does not exceed 200 sccm.
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 Bendix® ST-4™ Safety Valve Compressor Seal Kit (Minor) Pc. No. K051352 consists of the following: Item Qty.
These items are also referenced in the following procedures and are denoted by the numbers in parenthesis. CYLINDER HEAD, COOLING PLATE & VALVE PLATE ASSEMBLY 1. Remove the sealing ring (2) and discharge safety valve (1) from the compressor cylinder head. 2. Remove the two short hex head screws (4) and eight long hex head screws (3) from the compressor cylinder head. 3.
Repeat this process on the engine mounting face as well. Follow the instructions contained in the vehicle maintenance manual in lieu of the instructions and procedures presented in this manual. 2. Carefully remove all gasket material adhering to the deck (top) of the crankcase. Remove any carbon deposits from the deck of the crankcase. Make certain not to scratch or mar the gasket surfaces. CYLINDER HEAD, COOLING PLATE & VALVE PLATE ASSEMBLY 1.
CRANKCASE FRONT COVER 1. Position the new cover (9) over the hole in the front of the crankcase. Using a rubber mallet, drive the cover into the hole in the front of the crankcase until the outside diameter of the cover is flush with the cast surface. CRANKCASE SIDE COVER 1. Position the gasket (11) on the crankcase side cover. Install the crankcase side cover on the side of the crankcase using the six (6) cap screws previously removed. “Snug” all six cap screws then torque to 97–115 in-lbs (11–13 Nm).
3. Install any supporting brackets on the compressor in the same position(s) noted and marked during removal. 4 1 4. Inspect all air and coolant lines and fittings before reconnecting them to the compressor. Make certain o-ring seals are in good or new condition, the threads are clean, and the fittings are free of corrosion. Replace as necessary. 5 3 9 8 5. Install the discharge and coolant fittings, if applicable, in the same position on the compressor noted and marked during disassembly.
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. Column 1 Column 2 Typical Discharge Compressors Line No. of Spec'd Axles I.D. Length Vehicle Used for: Low Air Use Compressor with less than 15% duty cycle e.g. Line haul single trailer w/o air suspension, air over hydraulic brakes. 1/2 in. 5 or less e.g. Line haul single trailer with air suspension, RV, school bus.
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: What it may indicate: 4.0 Oil in Supply or Maintenance Service Reservoir (a) If air brake charging system (air dryer installed) ® maintenance has not been (If a maintained Bendix ® performed. That is, reservoir(s) PuraGuard system ® have not been drained per the filter or Bendix PuraGuard® QC oil schedule in Table A on page coalescing A-3, Column 4 and/or the air filter is installed, call dryer maintenance has not been 1‑800‑AIR‑BRAKE performed as in Column 3.
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. (f) Insufficient coolant flow. Inspect coolant line. Replace as necessary. Inside Diameter (I.D.) is 1/2". Inspect the coolant lines for kinks and restrictions and fittings for restrictions. Replace as necessary. (f) (e) Check temperature as outlined in Test 3 on page A-14.
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 the 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 Technician removes governor. 13.0 Reservoir safety valve releases air. 14.0 Air dryer doesn’t purge. (Never hear exhaust from air dryer.) 15.0 Compressor constantly cycles (compressor remains unloaded for a very short time.) (b) is not applicable for the compressor featured in this SD sheet —- information is shown for reference only.
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 Bendix® 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) Bendix® Air System Inspection Cup (BASIC™) Test Information Drain contents of ALL air tanks into Bendix® Basic™ cup * If the number of days since the air tanks were drained is unknown - use the 30 day line. ** Note: Typical air dryer cartridge replacement schedule is every 3 yrs/ 300K miles for low air use vehicles and every year/100K miles for high air use vehicles. Replace the Compressor.
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. 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.
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 Point Total 360cc Single School Bus / RV / Air over Hydraulic any a 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 a a a a 2.5 - 9 Pick-up & Delivery Furniture a 9.5 -13 a a 3-6 6.5 - 9 Line Haul a 9.5 - 13 Dump 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.
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