Operator's Manual for Mack B Series Trucks. A rare early manual for Mack B model gasoline trucks. Chapters cover Unit ID, Model Data on B-20P, B30B, B30P,T,X, B30S, B31P, B34B, B35B, B42P, B42T, B42ST, B42S, B42X, B421T, B41X, B43X, B41S, B43S, B50T, B60P, B60T, B60LT, B60ST, B61T, B61LT, B61ST, B60S, B62SX, B61S, B63SX, B60X, B65LT, B70T, B70ST, B71T and B71ST. Also includes Break-In, Instruments and Controls, Operation, Lubrication, Maintenance for Magnadyne gasoline engines EN-291, EN-331 & EN-401 and Thermodyne gasoline engines EN-431A, EN-464A & EN-707B. Cooling System, Shutter Control Valve Adjustment, Electrical System, Clutches, Transmissions, Braking Systems, Steering, Rear Axles, Preventive Maintenance and Troubleshooting Suggestions are also described in detail. Highly illustrated with numerous pictures, charts and tables. Professionally reprinted from the original, 84 pages.