T138 1980 BRAKE SYSTEM USAGE CHART Con I 1 980 P TRUCK 42 MODEL GASOLINE ENGINE VEHICLE SPEUFICATIONS BRAKE SYSTEM SPECIFICATIONS OPT HVY BASE BRAKES DUTY BRAKES REAR BRAKE IERCHAND BRAKE MERCHAIII WHEELS RPO RPO RPO RPO IEE 2Hl ZlH L M Sw P20842 125 0 6800 SINGLE JB6 STD JB7 J55 P20842 125 0 7500 SINGLE JB7 J55 P20842 125 0 8000 SINGLE JB7 J55 P21042 6800 SINGLE JB0 STD JB7 J55 P2104Z 7500 SINGLE JB7 J55 P21042 8000 SINGLE JB7 J55 P30842 125 0 7600 SINGLE JB7 STD JB8 J55 P3084Z 125 0 8200 SINGLE JB7 STD JB8 J55 P30842 125 0 9000 SINGLE JB8 J55 P30842 125 0 9000r DUAL JB8 J55 P30842 125 0 10000 DUAL JB8 J55 P30842 125 0 11500 DUAL JB8 J55 P30842 125 0 12000 DUAL JF9 H22 ur H23 P30842 125 0 14000 DUAL JF9 H22 or H23 P30842 125 0 14500 DUAL JF9 H22 or H23 P31042 133 0 7600 SINGLE JB7 STD JBB J55 P31042 133 0 8200 SINGLE JB7 STD JBB J55 P31042 133 0 9000 SINGLE JB8 J55 P31042 133 0 9000 DUAL JB8 J55 P31042 133 0 10000 DUAL JB8 J55 P31042 133 0 11500 DUAL JB8 J55 P3104Z 133 0 12000 DUAL JF9 H22 or H23 P31042 133 0 14000 DUAL JF9 H22 ur H23 P31042 133 0 14500 DUAL JF9 H22 or H23 P31442 157 0 7600 SINGLE JB7 STD JBB J55 P31442 147 0 8200 SINGLE JB7 STD JB8 J55 P31442 157 0 9000 SINGLE JB8 J55 P31442 157 0 9000 DUAL JB8 J55 P31442 157 0 10000 DUAL JB8 J55 P31442 157 0 11500 DUAL JB8 J55 P31442 157 0 12000 DUAL JF9 H22 or H23 P31442 157 0 14000 DUAL JF9 H22 or H23 P31442 157 0 14500 DUAL JF9 H22 or H23 WAREHOUSlNG AND DISTRIBUTION DIVISION OF GENERAL MOTORS CORPORATION LT TRUCI 52A 4 000 GROUP uu s REV 144