User manual BENDIX BRAKE CHAMBERS

[. . . ] Current production Type 20 chambers and larger, generally have 3/8 in. NPT ports to facilitate compliance with FMVSS 121. NON PRESSURE PLATE MOUNTING BOLTS SPRING INLET PORT DIAPHRAGM PUSH ROD ASSY. YOKE PRESSURE PLATE INLET PORT CLAMP RING NUTS & BOLTS LOCK NUT CLAMP RING SD-02-1302 1 OPERATION Controlled air pressure enters the brake chamber through the inlet port and acts upon the diaphragm moving the push plate and rod assembly forward. When the brake chamber is used to actuate cam type brake foundation assemblies, the yoke (which is threaded on the push rod) is connected to a slack adjuster, which in turn is connected to the brake cam shaft. [. . . ] Push rod travel should be as short as possible without brakes dragging. Adjust travel of push rod at slack adjuster if necessary. Using soap solution, coat clamping ring(s). If leakage is detected, tighten clamping ring only enough to stop leakage. DO NOT OVERTIGHTEN as this can distort sealing surface or clamping ring. Coat area around push rod hole (loosen boot if necessary). If leakage is detected, the diaphragm must be replaced. REMOVING AND INSTALLING A. Mount brake chamber to mounting bracket. Check the angle formed by the centerline of the push rod and slack adjuster. This angle should be greater than 90° in the released position and approach 90° at maximum readjustment stroke. Check to be sure hoses are properly supported and clamped if necessary to provide proper clearance. 2. Install boot or o-ring on non-pressure plate (if applicable). Position non-pressure plate on push rod, and press plate down against tension of spring until plate bottoms on flat surface. Clamp rod with vise grips (protect rod) at the plate. If installing single clamp ring, position ring over clamping surface of non-pressure plate. Check alignment marks (made before disassembly) and position diaphragm in pressure plate and place on nonpressure plate. If installing single clamp ring, work the clamp ring over the clamping surface of the pressure plate and draw the clamp lugs together with vise grips or a similar tool. Install bolt and nut in clamp and tighten, tapping with a soft faced mallet to center the clamp ring if necessary. Release grip on push rod and install remaining bolt and nut. Install nuts and bolts evenly and only sufficiently to eliminate leakage. TESTING OF A REBUILT BRAKE CHAMBER Perform tests outlined in "Operating and Leakage Tests" section. DISASSEMBLY Clean exterior of brake chamber and mark parts in relation to position to each other so that it may be assembled in the same way. NOTE: If brake chamber is to be dismantled without removing non-pressure plate from vehicle, slack adjuster should be backed-off. [. . . ] 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. [. . . ]