User manual BENDIX AD-2 AIR DRYER

[. . . ] ® Bendix® AD-1TM and AD-2TM Air Dryers AD-1TM AIR DRYER AD-2TM AIR DRYER FIGURE 1 The air dryer collects and removes moisture and contaminants before the air reaches the first reservoir. It is distinctly different than a reservoir drain valve or aftercooler in that it provides "dry air" for the air brake system. The daily draining of the system's reservoirs is no longer necessary, thus reducing maintenance considerably when compared to an air brake system without an air dryer. In a system without an air dryer, the life of air brake components is substantially reduced because of contact with water and oil in the system and since the air dryer removes water and oil in vapor form, life of the component devices is substantially increased when the air dryer is used. The air dryer can be used on most highway vehicles where normal compressor loaded time is 90 seconds or less and unloaded time is 30 seconds or more. [. . . ] Remove and discard the large o-ring around the end cover. Remove the cap nut and discard the cap nut o-ring. Place the handle of a large screwdriver in a vise and secure it. Place the slot in the plunger (cap nut end) over the blade of the screwdriver, hold it securely and remove the nut from the plunger using a 1/2" socket wrench. Clean and inspect the plunger bore and the valve seat. Remove and discard the three o-rings from the plunger. NOTE: If during the serviceability checks it was determined that the heater and thermostat were defective, use the following procedure. It is not necessary to replace this assembly each time the purge valve is rebuilt. FIGURE 15-1 FIGURE 15-2 11. Remove the square cut seal ring at the bottom of the thermostat bore. Remove the screw, retaining clip, o-ring, and the heater element. Inspect the bore for corrosion and if necessary, clean it. FIGURE 14 ASSEMBLY 13. Install the heater element, securing it in the end cover with the retainer clip and screw. Install the square cut seal ring in the thermostat bore. 9. Remove the two screws that secure the shield or thermostat retaining clip to the end cover. Remove the shield or clip and the thermostat and inspect the bore for corrosion. 10 15. Install the thermostat metal side down in the end cover bore and secure it in place using the retaining clip or shield and the two screws. Lubricate and install the o-rings on the plunger and cap nut. Lubricate the plunger bore and install the spring and plunger (through the cap nut end). Install the valve on the plunger, making certain the chamfered end of the valve is in contact with the metal seat of the body. Using the screwdriver held in the vise, as described in Steps 4 & 5, compress the plunger into the bore while installing and tightening the nut. Lubricate and install the large diameter o-ring around the end cover assembly. NOTE: If during the serviceability checks it was determined that the thermostat was defective, use the following procedure. It is not necessary to replace this unit each time the end cover is rebuilt. [. . . ] (Cold weather operation only. ) Result of reversing the inlet and outlet connections. (See Symptom #4, Cause E. ) Excessive system pressure build up within air dryer; caused by either plugged desiccant, check valve failure, frozen or obstructed discharge line (between air dryer and first reservoir) or governor failure in conjunction with safety valve failure. A. REMEDY With compressor loaded, apply soap solution on purge valve exhaust, to test for excessive leakage. Check governor for proper "cut-in", "cut-out" pressure and excessive leakage in both positions. [. . . ]