User manual BENDIX AD-9 AIR DRYER

[. . . ] Bendix® AD-9TM Air Dryer OUTER SHELL OUTER SHELL END COVER END COVER CONTROL PORT CHECK VALVE ASSEMBLY DELIVERY PORT DELIVERY PORT WIRING HARNESS CONNECTION SUPPLY PORT WIRING HARNESS CONNECTION CONTROL PORT SUPPLY PORT CHECK VALVE ASSEMBLY EXTENDED PURGE AD-9TM AIR DRYER STANDARD AD-9TM AIR DRYER FIGURE 1 - AD-9TM AIR DRYER MODELS DESCRIPTION The function of the AD-9TM air dryer is to collect and remove air system contaminants in solid, liquid and vapor form before they enter the brake system. It provides clean, dry air to the components of the brake system which increases the life of the system and reduces maintenance costs. The AD-9TM air dryer consists of a desiccant cartridge and a die cast aluminum end cover secured to a cylindrical steel outer shell with eight cap screws and nuts. The end cover contains a check valve assembly, a safety valve, three threaded air connections and the purge valve housing assembly. [. . . ] The majority of highway vehicles in use today will meet these basic requirements however, some may not. Examples of vehicles that may not meet the requirements include, bulk trailer unloading operations and other high air consumption/continuous flow systems. While the AD-9TM air dryer can be used on these vehicles the standard installation procedure presented in this manual may require modification to assure proper operation and service life. Consult your local authorized Bendix parts outlet or sales representative for additional information. Charge Cycle Time - The AD-9TM air dryer is designed to provide clean, dry air for the brake system. When a vehicle's air system is used to operate non-brake air accessories it is necessary to determine that during normal, daily operation the compressor should recover from governor "cut-in" to governor "cut-out" (usually 100 psi to 120 psi) in 90 seconds or less at engine RPMs commensurate with the vehicle vocation. If the recovery time consistently exceeds this limit, it may be necessary to "bypass" the air accessory responsible for the high air usage. Consult your local authorized Bendix parts outlet or sales representative for additional information. Purge Cycle Time - During normal vehicle operation, the air compressor must remain unloaded for a minimum of 20 seconds for the standard AD-9TM air dryer or 30 seconds for the Extended Purge model. These minimum purge times are required to ensure complete regeneration of the desiccant material. If the purge time is occasionally shorter than the times specified, no permanent ill effect should be expected, however, if the purge time is consistently less than the minimum, an accessory by-pass system must be installed. European Air Brake Systems - Brake systems that incorporate compressors without integral unloading INSTALLATION 1. Install the assembled AD-9TM air dryer back onto the vehicle by slipping it into the upper mounting bracket. Align the two unused holes in the end cover with the bottom mounting bracket such that the bottom bracket supports the air dryer. Using the remaining two 3/ 8" cap screws (18), four special washers (17), and two lock nuts (19), secure the air dryer to the lower bracket. Tighten the 5/16" X 4-1/2" hex cap screw (25) and nut (28) on the upper mounting bracket saddle (27) and strap (26). Reconnect the three air lines to the proper ports on the end cover (identified during disassembly). Reconnect the vehicle wiring harness to the AD-9TM air dryer heater and thermostat assembly connector by plugging it into the air dryer connector until its lock tab snaps in place. Before placing vehicle back into service, perform the Operation and Leakage Tests stated elsewhere in this manual. 10 mechanisms and/or utilize a compressor discharge line unloader valve have special AD-9TM air dryer installation requirements. Consult your local authorized Bendix parts outlet or sales representative for additional information. Air Compressor Size - Although the AD-9TM air dryer can be used in conjunction with larger compressors, it was designed primarily for units rated for up to 17 CFM. It is recommended that when using the AD-9TM air dryer with a compressor which has a rated displacement exceeding 17 CFM that an authorized Bendix parts outlet or Bendix marketing representative be contacted for assistance. [. . . ] Add bracket supports or change air dryer mounting location if necessary. Check for proper compressor installation; if symptoms persist, replace compressor. 21 AD-9TM AIR DRYER TROUBLESHOOTING CHART (Continued) SYMPTOMS CAUSE E. Constant seepage of air at air dryer purge valve exhaust (non-charging mode. ) A. The air dryer purge piston cycles rapidly in the compressor unloaded (noncompressing) mode. [. . . ]