Document V3DOn6Drqy8wvNn1RxVxvdM24

BULLETIN MAR. 17. 1972 No. Q68 under brakes FOR BRANCHES. DISTRIBUTORS AND CUSTOMERS. SPRING LOADED BRAKE CHAMBER SERVICING PLAINTIFF'S EXHIBIT IMPORTANT BULLETIN CAUTION PURPOSE To caution all field personnel to be most careful when working on spring loaded brake chambers. INFORMATION Moreandmore spring loaded brake chambers are being used on trucks of all makes. Spring loaded auxiliary brakes are STANDARD equipment on Mack chassis with either cam or wedge type brakes. Because of this, it is important to remind all Customer, Distribu tor or Branch service personnel that spring loaded brake chambers contain heavy coil springs which, in many cases, must be retained either in an arbor press, special fixture, safety cage or by com pressing the spring with a stud or capscrew arrangement. Inform mechanics not to just disassemble brake chambers. Units of various styles differ in construction. If in doubt, place units under controlled compression, such as in an arbor press or special fixture. Literature is available on spring loaded brakes as used on Mack trucks. Distribution of various items has been made in the past, however, any of the following literature can be obtained through Mack Service outlets. Requests from these locations will be for warded to the Technical Service Department at Allentown, Pa. for handling. CAUTION It is extremely important to use a retaining method on all spring brake chambers. The spring is under heavy compression and, if improperly handled, can expand rapidly with great force and cause injury. As a guide, the following methods of retention are used by the spring brake manufacturers: ANCHORLOK Remove release stud assembly from carrying pocket built into chamber body. Remove dust cap and insert stud into pressure plate. Turn one quarter turn to capture pressure plate. Tighten nut on stud until spring is fully caged. rtiNHO IN U S.A. (Continued Over) Service Operations, Allentown, Pa. U.S. A. Mack BERG Compress spring by backing off release bolt. Application of air to charge brake will reduce tension on center bolt, but it is not abso lutely necessary. MAXIBRAKE Special Maxibrake service tool is available to eliminate hazards of spring brake disassembly. STOPMASTER BRAKES Always cage power springs by turning caging about 18 to 21 turns clockwise which compresses spring. NOTE Even with these compression devices, ele ments should be retained in safety cages or in arbor press. Be sure that precautions as provided by manufacturer are followed. Literature is available as desired, on any specific model spring brake. RECOMMENDATION Caution all shop personnel to be sure they understand how to disassemble spring loaded brake assemblies. Service Manager Shop Foreman Lead Men Mechanics 1st Shift 2nd Shift 3rd Shift