BENDIX BW1586 User's Manual
Contents
1. tubing or hose fittings in the upper body of the QR N valve If a thread sealant is used make certain that this material will not enter the valve during use IMPORTANT WHEN INSTALLING FITTINGS DO NOT TORQUE BEYOND 12 ft lbs 16 3 N M for the supply port 10 ft Ibs 13 6 N M for the delivery ports OR DAMAGE TO THE UPPER BODY MAY RESULT Connect the air lines to the QR N valve as identified in Step 4 of the Removal Perform the Operating and Leakage Tests before placing the vehicle in service BW1586 2004 Bendix Commercial Vehicle Systems LLC All rights reserved 3 2004 Printed in U S A2. DELIVERY PORT SEALING RING LOCKWASHER CAP SCREW SPRING FOLLOWER N DIFFERENTIAL SPRING INSERT A FIGURE 1 DESCRIPTION The function of the Bendix QR N quick release valve is to speed up the exhaust of air from the actuators it serves It is generally mounted on the vehicle axle midway between the two actuators connected to it In the standard Refer to Figure 1 QR N valve a flat circular diaphragm is installed between the nonmetallic upper body and stamped steel lower body An o ring seals the two body halves which are held together using four 1 4 machine screws and flange nuts In its standard configuration the QR N valve is supplied with a 1 psi 6 9 kPa maximum differential For example with supply pressure at 10 psi 68 9 kPa delivery pressure is 9 psi 61 8 kPa Higher differential pressures are available for special applications and are obtained by the addition of a spring and diaphragm follower to the standard QR N valve Refer to Insert A The QR N valve also comes in sustained black body and non sustained gray body differential versions Various pipe thread sizes are available for the single supply port and two delivery ports of the QR N valve Some versions of the QR N valve have a threaded exhaust port Refer to Insert B QR N valve mounting is accomplished via two 11 32 diameter holes on 1 1 2 centers SUPPLY PORT SD 03 905 UPPER BODY DELIVERY PORT i F
3. G amp INSPECTION 1 Clean the upper and lower body halves also diaphragm follower and spring if applicable in mineral spirits Do not immerse nonmetallic components for a prolonged period of time no more than 10 minutes Dry all parts thoroughly It is recommended that the diaphragm and sealing ring be replaced after disassembly Inspect the upper body for galled threads and cracks If found the entire QR N valve should be replaced Inspect the interior valve portion of the lower body for heavy corrosion and pitting If found replace the entire QR N valve assembly If applicable inspect the diaphragm follower and spring if applicable for any corrosion and pitting replace if necessary ASSEMBLY ils Place the supply port of the upper body down on aclean level work surface Install the flat circular diaphragm in the upper body making certain itis CENTERED If applicable install and center the diaphragm follower with its flat flange side against the diaphragm Install the spring on the diaphragm follower Install the sealing ring on the lower body and carefully install the lower body on the upper body Make certain that the diaphragm remains centered in the upper body and the sealing ring enters its groove in the upper body Install the four 1 4 flange nuts and bolts and torque to 60 inch pounds 6 78 N M INSTALLING THE QR N VALVE 1 2 Mount the QR N valve on the vehicle Install the
4. THREADED EXHAUST PORT INSERT B OPERATION With no air pressure applied to the QR N valve Refer to Figure 1 the diaphragm is slightly flexed by the upper and lower body In this condition the center portion of the diaphragm rests on the exhaust port in the lower body while the outer edge and opposite side of the diaphragm rests against the sealing lip of the upper body APPLY Air entering the supply port of the QR N valve causes the center portion of the diaphragm to seal the exhaust port Simultaneously the outer edge of the diaphragm moves away from the sealing lip of the upper body allowing air to flow from the supply port out the delivery ports BALANCE When air pressure on both sides of the diaphragm is approximately equal 1 psi differential the natural resiliency of the diaphragm material causes the outer edge of the diaphragm to move into contact with the upper body sealing lip The QR N valve exhaust remains sealed because air pressure bears against the center portion of the diaphragm from one side only RELEASE When air pressure is reduced or removed from the QR N valve supply port the air pressure on the delivery side of the diaphragm is greater than that on the supply side The higher delivery side pressure holds the outer edge of the diaphragm against the upper body sealing lip while simultaneously moving the center portion away from the exhaust port Air from the delivery ports flows out the exhau
5. h and strength as the original equipment C Make certain that when replacing tubing or hose all supports clamps or suspending devices that were originally installed by the vehicle manufacturer are reinstalled 6 Devices with stripped threads or damaged parts should be replaced Repairs requiring machining should not be attempted REMOVING THE QR N VALVE 1 OF a a Park the vehicle on a level surface Block the wheels and or hold the vehicle by means other than the air brakes Drain all air brake system reservoirs Identify mark and disconnect all air lines from the valve Remove all tubing or hose fittings from the valve Remove the valve mounting hardware and the valve DISASSEMBLY The following disassembly procedure is provided as a reference Before disassembling the QR N valve a Bendix maintenance kit or genuine replacement parts should be available i 3 Remove the four 1 4 flange nuts and bolts that secure the upper and lower body halves NOTE Before removing the last two nuts and bolts completely check the opening between the body halves to determine if the QR N valve has a differential spring installed If so a light spring load should be anticipated and can be easily controlled by manually holding the body halves together Separate the body halves and remove the diaphragm and diaphragm follower and spring if so equipped Remove the sealing ring between the body halves CLEANIN
6. placed rather than repaired Do not attempt repairs requiring machining or welding unless specifically stated and approved by 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 OPERATING AND LEAKAGE TESTS 1 Apply 100 psi 689 kPa air pressure to the supply port of the QR N valve and note that the device connected to the QR N valve responds promptly 2 With 100 psi 689 kPa air pressure applied to the QR N valve SUPPLY port apply a soap solution to the exhaust port and around the junction of the upper and lower body halves A No leakage is permitted between the body halves B Leakage of greater than a 1 25 4 mm bubble in 3 seconds at the exhaust port is unacceptable 3 Release the air pressure at the supply port and note that the device connected to the QR N valve responds promptly and returns to a zero air pressure condition 4 Ifthe QR N valve does not function as described or if leakage is excessive it is recommended that it be replaced with a new or remanufactured unit or repaired using a genuine Bendix maintenance kit 5 Use only genuine Bendix replacement parts and componenis A Only components devices mounting and attaching hardware specifically designed should be used B Replacement hardware tubing hose fittings etc should be of equivalent size type lengt
7. ration EXTREME CAUTION should be used to prevent personal injury resulting from contact with moving rotating leaking heated or electrically 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 Ifthe 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 re
8. st When air pressure on the delivery side of the diaphragm equals the pressure on the supply side the center portion of the diaphragm moves into contact with the exhaust port PREVENTIVE MAINTENANCE Important Review the Bendix Warranty 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 QR N valve should be inspected every 12 months or 3600 operating hours whichever comes first for proper operation Should the QR N valve not meet the elements of the operational tests noted in this document further investigation and service of the valve may be required 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 ope
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