1 GM04 255 I osoaas A X 21 9 1 1 20 2 l 2 0 ge l Q Qx I 1 I 1 B sa 18 a 55k v 1 Y X 17 16 T Q zz y J 1 25 2 s 1 4 A 5 7 33 Q 25 26 1 31 27 I 1 X 28 M 32 E 1 1 1 4 3 30 1 6 1 29 V 1 V V 11 10 DM5189E121 GM04 255 1986 1987 C BRAKE BOOSTER VACUUM DUAL DIAPHRA GM DELCO NOTE SEE PARTS CATALOG FOR POWER BOOSTER CHART IN GROUP 4 901 1 1 N S BOOT ONLY SERVICED 1987 AND LATER 1 2 7 2 N S SILENCER 1 2 4 3 N S VALVE VACUUM CHECK 1 2 3 4 N S GROMMET 1 2 3 5 N S SWITCH VACUUM SOME MODELS 1 2 5 6 N S GROMMET 1 2 5 7 N S SEAL FRT HOUSlNG 1 2 I 8 N S BEARING PRIM P STON 1 2 9 N S HOUSING RR 1 I 10 N S HOUSING FRT 1 11 N S SPRING RETURN 1 1 12 4 924 ROD VAC PWR BOOS PISTON 1 13 N S RETAINER REACTION 1 14 N S SILENCER POWER HEAD 1 2 4 15 N S RETAINER DIAPHRAGM 1 2 16 N S DIAPHRAGM PRIM 1 2 17 N S PLATE PRIM SUPPORT 1 18 N S BEARING PISTON SECD 1 2 19 N S DIVIDER HOUSING 1 20 N S DIAPHRAGM SECD 1 2 21 N S PLATE SUPPORT SECD 1 22 N S DISC REACTION 1 2 6 23 N S PISTON REACTION 1 6 24 N S RETAINER BODY REACTION 1 4 6 Q 25 N S BODY REACTION 1 6 I 6 26 N S SPRING A R VALVE 1 4 27 N S BUMPER REACTION 1 2 4 28 N S RING RETAIN NG 1 2 4 1992 GENERAL MOTORS SERVICE PARTS OPERATIONS BUICK 44C 4 000 GROUP 4 142 8 92