User manual BENDIX PP-DC PARK CONTROL VALVE

[. . . ] When the button is pushed in, the valve delivers air to the spring brake chambers (usually through a spring brake valve such as the Bendix® SR-1TM valve and a relay or quick release valve). The air releases the spring brakes for normal vehicle operation. To apply the parking brakes, the button is pulled out, which exhausts the PP-DCTM valve delivery and releases air from the spring brake chambers. If total system pressure drops below 20 to 30 psi, the valve will automatically "pop out, " which removes the hold-off air in the chambers and applies the spring brakes. PARKING BRAKES RELEASED To release the parking brakes, the push-pull button is pushed in. [. . . ] Repair/replace as necessary. LEAKAGE AND OPERATIONAL TESTS To perform the following tests, connect two separate 120 psi air sources to the PP-DCTM valve supply ports. Tee an accurate test gauge into the supply lines, and provide for a means to control supply line pressure. Connect a small volume with a gauge to the delivery port. Supply the valve with 120 psi from the primary reservoir supply port. With the button out, coat the exhaust port and the plunger stem with a soap solution. Leakage should not exceed a 1" bubble in 5 seconds. There should be no leakage from the secondary reservoir supply port. With the button out, supply the valve with 120 psi from the secondary reservoir supply port. There should be no leakage from the primary reservoir supply 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 PP-DCTM valve should be inspected every 6 months or 1500 operating hours, whichever comes first, for proper operation. Should the PP-DCTM valve not meet the elements of the operational tests noted in this document, further investigation and service of the valve may be required. 4 BUTTON SCREW COVER CHECK VALVE SEAT GUIDE SPOOL 1 2 3 PLUNGER STEM 7 BODY 8 PLUNGER 9 INDEX TABS 4 5 6 FIGURE 6 - EXPLODED VIEW 5 3. With the button in, coat the exhaust port and the plunger stem with a soap solution. Leakage at both areas should not exceed a 1" bubble in 3 seconds. With the button out, supply either supply port with 120 psi of air. Air pressure should rise in the delivery volume equivalent to supply pressure. Delivery pressure should exhaust to 0 psi. Decrease supply pressure at the secondary service reservoir supply port at a rate of 10 psi per second. Primary supply pressure and delivery pressure should not drop below 100 psi. Repeat the test for decreasing primary service reservoir pressure. [. . . ] Push on the button a number of times to make sure the plunger moves freely throughout its range of motion. NOTE: BEFORE PLACING THE VEHICLE BACK INTO SERVICE, PERFORM THE "LEAKAGE AND OPERATIONAL TESTS" IN THIS MANUAL. INSTALLATION 1. Install the PP-DCTM valve in its location on the dashboard. Using the mounting hardware saved in "REMOVAL, " secure the valve to the vehicle. [. . . ]