7- 1 CHAPTER 7 - AIR BRAKE SYSTEM TABLE OF CONTENTS i List of lllustratlons 7-2 7.0 General 7-3 7.1 Brake System Operation 7-6 7.2 Carbody Brake Components 7-8 7.2.1 Carbody Equipment Common to All Cars 7-8 7.2.2 Carbody Components of the D-22 System 7-11 7.2.3 Carbody Components of, the 26-C System 7-11 7.3 Truck-Mounted Components 7-19 7.3.1 Tread Brake Components 7-19 7.3.2 Disc Brake Components 7-27 7.4 Decelostat Wheel Slide Protection System 7-33 7.4.1 System Operation 7-33 7.4.2 Deeelostat System Components 7-34 7.4.3 General Maintenance 7-40 7.4.4 Periodic Maintenance 7-41 7.5 Brake Condition Indication System 7-45 7.6 Maintenance and Overhaul Procedures with Part Lists 7-49 7.6.1 Control Valve & Relay Valves 7.6.2 Air Brake System Valves 7.6.3 Brake Cylinders & Slack Adjusters 7.6.4 WABCO TFM Disc Brake Service Manual & Parts Catalog 7.6.5 Deeelostat 7.7 Brazing Piping Procedure 7-57 7.8 Drawing List 7-61 7 2 CHAPTER 7 - AIR BRAKE SYSTEM LIST OF ILLUSTRATIONS Page 7.1 Car Brake Schedules 7-4 7.2 Simplified Air Brake System Schematic 7-7 7.3 WABCO D-22 System Piping 7-12 7.4 WABCO D-22 System Piping Parts List 7-13 7.5 WABCO 26-C System Piping 7-14 7.6 WABCO 26-C System Piping Parts List 7-15 7.7 Diagramatic D-22 System 7-16 7.8 Diagramatic 26-C System 7-17 7.9 Truck Tread Brake Components 7-22 7. 10 Truck Tread Brake Components Parts List 7-23 7. 11 Truck Disc Brake Components 7-28 7. 12 Truck Disc Brake Components Parts List 7-29 7. 13 Decelostat System Component Location 7-36 7. 14 Decelostat System Parts List 7-37 7. 15 Speed Sensor Application 7-38 7. 16 E-5 System Components 7-39 7 17 E-5 Decelostat Self-Test Procedure 7-42 7 18 E-5 Controller Test Points 7-43 7 19 Brake Pressure Switch & Testor 7-46 7 2O Brake Applied Indicator 7-51 7 21 WABCO Repair and Testing Specification Index 7-53 7 22 WABCO Brake Component Part Lists 7-54 7 23 Brazing Cleaning Procedure 7-59 7. 24 Brazing - Applying Alloy 7-59 7 - 3 CHAPTER 7 AIR BRAKE SYSTEM 7.1 General All HEP single level converted cars are equipped with automatic air brakes. Most cars use the D-22 schedule, but the remainder use the 26-C. Refer to figure 7.1 for brake schedules. Past features that helped to improve response time for D-22 schedules in application and release, such as electropneumatic devices, HSC equipment, or "straight air" have been removed. Speed governor control equipment, which regulated tread brake shoe forces at high speed for cars with cast iron shoes has also been removed. Similar features used with 26C equipment schedules have also been removed. All conventional cars have been converted from cast iron to high friction composition brake shoes. As part of the HEP conversion, a i" main reservoir pipe was added. This line only passes through the car end to end, not connecting to any car equipment. Its function is to supply auxiliary air to other functions such as air springs and door seals on the Amfleet and Superliner equipment. While some cars are tread brake, most are disc brake equipped. All disc units are now truck frame mounted, TFM. Many cars were originally C-frame, CF. They were converted to TFM during the HEP upgrade, to reduce maintenance requirements. All disc brake cars are now equipped with the WABCO E-5 Decelostat wheel slide protection system. Tread brake cars have been wired for the E-5 system, but are equipped with neither the dump valves nor the E-5 control unit. Space for the controller was provided in the electric locker of each of these cars, for possible future installation. As part of the 27 point trainline, two wires function to give brake applied and released light indication to the locomotive. Aside from these modifications, and the fact that all cars are now set up for composition shoes, the brake system is similar to when the car was built. 7 - 4 Figure 7.1 BRAKE SCHEDULES Car Brake Modification Control Relay Slack Cylinder Cylinder Press Numbers Type Kit Valve Valve Adj Size F.S. Emg 1126-27 Tread --- D22 1128-31 TFM Yes D22 1132 Tread --- D22 1133-36 TFM None D22 1137-38 Tread --- D22 1139 TFM None D22 1140 Tread --- D22 1141-49 Tread --- D22 1150-58 Tread --- D22 1159-68 Tread --- D22 1169 Tread --- D22 1170-74 TFM Yes D22 1610-17 Tread --- D22 1618 Tread --- D22 1619-21 Tread --- D22 1622-25 TFM Yes D22 1626-27 Tread --- D22 1628-37 Tread --- D22 2050-56 Tread --- D22 2080-93 TFM Yes D22 2080-93 TFM Yes D22 2430-41 TFM Yes D22 2442-56 TFM Yes D22 2457-60 TFM Yes D22 2461-68 TFM Yes D22 2469-73 TFM Yes D22 7 5 Figure 7.1 BRAKE SCHEDULES (continued) Car Brake Modification Control Relay Slack Cylinder Cylinder Press Numbers Type Kit Valve Valve Adj Size F.S. Emg 2474-78 Tread --- D22 2479-81 Tread --- D22 2482 TFM Yes D22 2871-79 TFM Yes D22 2880-94 TFM Ye_ D22 2895-96 Tread --- D22 3100-05 Tread --- D22 3106-12 Tread --- D22 3113-17 TFM None D22 3118-27 TFM None D22 4000-14 TFM Yes D22 4015-26 TFM Yes D22 4600-26 TFM None 26C 4627-45 TFM None 26C 4646-48 TFM None 26C 4649-50 TFM Yes D22 4700-39 TFM Yes D22 4740-41 TFM Yes D22 4742 TFM Yes D22 5000-08 TFM Yes D22 7000-07 TFM None D22 7600 TFM None D22 7601-18 Tread --- D22 8500-10 TFM Yes D22 8511-20 Tread --- D22 8521-25 Tread --- D22 8526-28 TFM Yes D22 7 - 6 7.1 Brake System Operation The car air brake system has the responsibility of safely stopping the train, and accordingly, it is designed as a fail-safe system. That is, everything must work properly for the brakes to release. Fundamental to this concept is that the brake system on each car is self-sufficient. Refer to figure 7.2 for a highly simplified air brake system schematic. The brake pipe (i) is a 1¼"pipe which runs the length of the train, starting in the locomotive. Car-to-car connections are via flexible air hoses and the coupling gladhands. At the ends of each car angle cocks are provided to allow the brake pipe to be sealed at the rear of the last car of the train. The locomotive feeds compressed air into the brake pipe, nominally at 110 psig, charging until the entire train is at this pressure. To apply train brakes, the brake pipe pressure is reduced from 110 psig. The greater the reduction, the harder the car brakes are applied. For example, a i_O0 pound reduction gives a mild brake application, 2__5 pound reduction gives full service, and exhausting to atmosphere gives an emergency application. The concept of lowering brake pipe pressure makes the brakes essentially fail safe. For example, should the train break in two, the brake pipe hoses will break apart, venting the brake pipe and applying the brakes. As an additional safety feature, each car is equipped with two conductor emergency valves, one at each end. Pulling the handle of this valve will also vent the brake pipe to zero pressure and cause an emergency application. It does not matter where in the train brake pipe air is vented, the brakes will apply, including those on the locomotive. The supply reservoir (2) is the one or two large air tanks which store compressed air for the car's own brake system. These tanks are charged from the brake pipe by the control valve. The control valve (3) is the heart of the brake system. The internal components monitor the brake pipe pressure and issue commands to the relay valve to apply, maintain or release the car brakes. It is also responsible for charging the supply reservoir from the brake pipe, as well as the auxiliary reservoir. Auxiliar_ reservoir (4) is the name given the small air reservoir used to supply air to the control valve for operation of the valve itself. I CONDUCTOR ANGLE COCK COCK EvAMLE(_ENCY l ANGLE CAR ,_ ,_ _[3_--___._,_NEXT 0000000 0 0 0 0 0 0 %_. 0 0 0 0 0 0 0 CAR HOSE O D I _CUTOUT COCK I .m 0 _ o CONTROL B 0 VALVE D 0 0 0 0 ® SUPPLY AIR Q r-', i"-i 0o :1 CONTROL AI R A 2(® AUXILIARY SUPPLY RESERVOIR 0 0 0 RESERVOIR 0 A 0 ® 0 BRAKE CYLINDER D A 0 AIR D A 0 A A A A o o"_o 13 o A q @RELAY J r--i r--, AAAA A A A x I VALVE %BR AKE CYLINDER EXHAUST z_ A A Z_ Z_ A m m Z_ A "4 I "4 7 - 8 The relay valve (5) is the device which controls the air flowing to the brake cylinders. It will apply, maintain or release the air pressure in the cylinders in response to the control valve commana. To apply the brakes, the relay valve takes air from the supply reservoir and directs it to the brake cylinders.