BENDIX BW1582 User's Manual
Contents
1. 100 sccm Note On some vehicles an exhaust line is connected to the exhaust port and piped outside the cab in which case it may be necessary to disconnect this line to make leakage check B If the double check valve is to be bench tested or tested on the vehicle two separately controlled air supplies must be connected to the inlet ports 1 Install an accurate test gauge in the outlet port or in a line from outlet port 2 Apply and release air to one inlet port and note that gauge registers application and release 3 Repeat by applying and releasing air to other inlet port 4 Leakage check should be performed at inlet ports of valve in the following manner a Disconnect the line from one inlet port b Apply air to other inlet port and coat opposite inlet port with soap solution Permissible leakage is a 1 bubble in 5 seconds 100 sccm c Repeat Step b applying air to other inlet port while checking opposite inlet port for leakage If the double check valve does not function as described or if leakage is excessive it is recommended that the valve be repaired or replaced with genuine Bendix parts The following instructions should prove helpful DISASSEMBLY 1 Remove the end cap s from the valve 2 Remove the grommets if applicable 3 Remove the shuttle and or shuttle guide disc and or disc guide depending upon type of valve PREVENTIVE MAINTENANCE Important Review the Bendix Warran2. 1 SD 03 2202 OPERATION As air under pressure enters either end of the double check valve inlet port the moving shuttle or disc responds to the pressure and seals the opposite port assuming it is at a lower pressure level than the other The air flow continues out the delivery port of the double check valve The position of the shuttle or disc will reverse if the pressure levels are reversed Double check valves are designed so that the shuttle or disc can never impede the backflow of air in the exhaust mode Figure 3 see page 2 illustrates a typical use of a double check valve to control a given device such as trailer brakes from either of two control sources Figure 4 see page 2 illustrates a typical use of a double check valve to supply air to a system or systems from either of two separate sources whichever is at the greater pressure level In this type of installation the pressure differential to which the valve is subjected may under certain conditions be minimal It is therefore suggested that performance of the double check valve will be optimized if it is mounted in the horizontal position DESCRIPTION Double check valves are used in an air brake system to direct a flow of air into a common line from either of two sources whichever is at the higher pressure They may be used for directing air flow for specific functions or to select the higher pressure of either of two sources of air as a supply source Bendix m
3. all o rings and o ring grooves with Bendix silicone lubricant Pc No 291126 or equivalent NOTE When using pipe thread sealant during assembly and installation take particular care to prevent the sealant from entering the valve itself Apply the sealant beginning with the second thread back from the end 1 Install the disc guide disc and or shuttle and shuttle guide 2 Coat all static seals such as o rings grommets etc with BW 650M Silicone lubricant BW 291126 It is not necessary to lubricate shuttles or discs 3 Install the grommets 4 Install the end cap s TESTING OF REBUILT DOUBLE CHECK VALVE Perform operating and leakage tests as described in Service Checks section 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 general precautions should be observed at all times 1 Park the vehicle on a level surface apply the parking brakes and always block the wheels Always wear safety glasses 2 Stop the engine and remove ignition key when working under or around the vehicle When working in the engine compartment the engine should be shut off and the ignition key should be removed Where circumstances require that the engine be in operation EXTREME CAUTION should be used to prevent personal injury resulting from contact with moving rotating leaking heated or electrical
4. anufactures two types of double check valves shuttle and disc Although the valves are somewhat different physically the same function is performed by both types The difference in the design of the two valves is that the shuttle type has a movable shuttle to seal off the lower pressure source whereas the disc type has a movable disc Bendix Double Check Valves FIGURE 1 DC 4 DOUBLE CHECK VALVE SHUTTLE TYPE FIGURE 2 DOUBLE CHECK VALVE DISC TYPE DELIVERY SUPPLY SUPPLY SHUTTLE GUIDE BODY O RING SUPPLY DELIVERY SHUTTLE VALVE VALVE DISC VALVE GUIDE BODY CAP O RING DELIVERY SUPPLY CAP 2 Reservoir Brake Valve Trailer Hand Control Valve SERVICE CHECKS OPERATING AND LEAKAGE TEST A When the double check valve is used in conjunction with a trailer control valve the following operating and leakage test can be made 1 Apply and release foot brake valve and note that the brakes apply and release on both tractor and trailer 2 Apply and release the trailer control valve and note that only the trailer brakes apply and release With trailer control valve applied check exhaust port of foot brake valve for leakage with soap solution Permissible leakage is a 1 bubble in 5 seconds 100 sccm 3 Apply and hold a full foot brake valve application Check exhaust port of trailer control valve for leakage with soap solution Permissible leakage is a 1 bubble in 5 seconds
5. ly charged components 3 Do not attempt to install remove disassemble or assemble a component until you have read and thoroughly understand the recommended procedures Use only the proper tools and observe all precautions pertaining to use of those tools 4 If the work is being performed on the vehicle s air brake system or any auxiliary pressurized air systems make certain to drain the air pressure from all reservoirs before beginning ANY work on the vehicle If the vehicle is equipped with an AD IS air dryer system or a dryer reservoir module be sure to drain the purge reservoir 5 Following the vehicle manufacturer s recommended procedures deactivate the electrical system in a manner that safely removes all electrical power from the vehicle 6 Never exceed manufacturer s recommended pressures 7 Never connect or disconnect a hose or line containing pressure it may whip Never remove a component or plug unless you are certain all system pressure has been depleted 8 Use only genuine Bendix replacement parts components and kits Replacement hardware tubing hose fittings etc must be of equivalent size type and strength as original equipment and be designed specifically for such applications and systems 9 Components with stripped threads or damaged parts should be replaced rather than repaired Do not attempt repairs requiring machining or welding unless specifically stated and approved by
6. the vehicle and component manufacturer 10 Prior to returning the vehicle to service make certain all components and systems are restored to their proper operating condition 11 For vehicles with Antilock Traction Control ATC the ATC function must be disabled ATC indicator lamp should be ON prior to performing any vehicle maintenance where one or more wheels on a drive axle are lifted off the ground and moving 4 BW1582 2007 Bendix Commercial Vehicle Systems LLC All rights reserved 3 2007 Printed in U S A
7. ty Policy before performing any intrusive maintenance procedures A warranty may be voided if intrusive maintenance is performed during the warranty period No two vehicles operate under identical conditions as a result maintenance intervals may vary Experience is a valuable guide in determining the best maintenance interval for air brake system components At a minimum the DC 4 valve should be inspected every 6 months or 1500 operating hours whichever comes first for proper operation Should the DC 4 valve not meet the elements of the operational tests noted in this document further investigation and service of the valve may be required Reservoir Reservoir Trailer Supply Spring Brake Control Double Check Valve FIGURE 4 DOUBLE CHECK VALVE SYSTEM WITH TWO SUPPLY SOURCES PP 7 Valve PP 1 Valve FIGURE 3 DOUBLE CHECK VALVE CONTROL OF SYSTEM FROM EITHER OF TWO CONTROL SOURCES Double Check Valve To Trailer Brakes 3 CLEANING AND INSPECTION 1 Clean all metal parts in mineral spirits and dry them completely 2 Inspect all parts for excessive wear or deterioration Inspect valve seats for nicks or burrs 3 Inspect the bores of the valve housing for deep scuffing or gouges Replace all parts that were discarded and any parts not found to be serviceable during inspection using only genuine Bendix replacement parts ASSEMBLY Before assembling the DC 4 valve lubricate
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