GM Full-Size Trucks 1980-1987 Repair Guide

VACUUM DIAGRAMS

Print

Below is a listing of vacuum diagrams for most of the engine and emissions package combinations covered by this manual. Because vacuum circuits will vary based on various engine and vehicle options, always refer first to the vehicle emission control information label, if present. Should the label be missing, or should the vehicle be equipped with a different engine from the truck's original equipment, refer to the diagrams below for the same or similar configuration.





Click image to see an enlarged view

Fig. Fig. 1: Vacuum hose schematic-1980

 


Click image to see an enlarged view

Fig. Fig. 2: Vacuum hose schematic-1980

 


Click image to see an enlarged view

Fig. Fig. 3: Vacuum hose schematic-1980

 


Click image to see an enlarged view

Fig. Fig. 4: Vacuum hose schematic-1980

 


Click image to see an enlarged view

Fig. Fig. 5: Vacuum hose schematic-1980

 


Click image to see an enlarged view

Fig. Fig. 6: Vacuum hose schematic-1980

 


Click image to see an enlarged view

Fig. Fig. 7: Vacuum hose schematic-1980

 


Click image to see an enlarged view

Fig. Fig. 8: Vacuum hose schematic-1980

 


Click image to see an enlarged view

Fig. Fig. 9: Vacuum hose schematic-1980

 


Click image to see an enlarged view

Fig. Fig. 10: Vacuum hose schematic-1980

 


Click image to see an enlarged view

Fig. Fig. 11: Vacuum hose schematic-1980

 


Click image to see an enlarged view

Fig. Fig. 12: Vacuum hose schematic-1980

 


Click image to see an enlarged view

Fig. Fig. 13: Vacuum hose schematic-1980 5.7L (LS9) and 6.6 (LF4) engines

 


Click image to see an enlarged view

Fig. Fig. 14: Vacuum hose schematic-1980

 


Click image to see an enlarged view

Fig. Fig. 15: Vacuum hose schematic-1980

 


Click image to see an enlarged view

Fig. Fig. 16: Vacuum hose schematic-1980

 


Click image to see an enlarged view

Fig. Fig. 17: Vacuum hose schematic-1980

 


Click image to see an enlarged view

Fig. Fig. 18: Vacuum hose schematic-1980

 


Click image to see an enlarged view

Fig. Fig. 19: Vacuum hose schematic-1980

 


Click image to see an enlarged view

Fig. Fig. 20: Vacuum hose schematic-1980

 


Click image to see an enlarged view

Fig. Fig. 21: Vacuum hose schematic-1980

 


Click image to see an enlarged view

Fig. Fig. 22: Vacuum hose schematic-1980

 


Click image to see an enlarged view

Fig. Fig. 23: Vacuum hose schematic-1980 5.7L (LT9) and 6.6L (LE4) engines

 


Click image to see an enlarged view

Fig. Fig. 24: Vacuum hose schematic-1980

 


Click image to see an enlarged view

Fig. Fig. 25: Vacuum hose schematic-1980

 


Click image to see an enlarged view

Fig. Fig. 26: Vacuum hose schematic-1980

 


Click image to see an enlarged view

Fig. Fig. 27: Vacuum hose schematic-1980 5.7L (LT9) and 6.6L (LE4 and LT9) engines

 


Click image to see an enlarged view

Fig. Fig. 28: Vacuum hose schematic-1980

 


Click image to see an enlarged view

Fig. Fig. 29: The Vehicle Emission Control Information label, located under the hood shows the vacuum hose schematic on 1981 and later vehicles

 


Click image to see an enlarged view

Fig. Fig. 30: 1984 250 (4.1L) 6-cylinder engine-2bbl federal, high and low altitude with manual transmission

 


Click image to see an enlarged view

Fig. Fig. 31: 1984 250 (4.1L) 6-cylinder engine-2bbl federal, high and low altitude with manual transmission alternate

 


Click image to see an enlarged view

Fig. Fig. 32: 1984 250 (4.1L) 6-cylinder engine-2bbl federal, high and low altitude with manual transmission alternate

 


Click image to see an enlarged view

Fig. Fig. 33: 1984 250 (4.1L) 6-cylinder engine-2bbl federal, high and low altitude with manual or automatic transmission alternate

 


Click image to see an enlarged view

Fig. Fig. 34: 1984 250 (4.1L) 6-cylinder engine-2bbl federal and low altitude with automatic transmission

 


Click image to see an enlarged view

Fig. Fig. 35: 1984 250 (4.1L) 6-cylinder engine-2bbl federal and low altitude with automatic transmission alternate

 


Click image to see an enlarged view

Fig. Fig. 36: 1984 250 (4.1L) 6-cylinder engine-2bbl federal and low altitude with automatic transmission alternate

 


Click image to see an enlarged view

Fig. Fig. 37: 1984 250 (4.1L) 6-cylinder engine-2bbl federal and low altitude with automatic transmission alternate

 


Click image to see an enlarged view

Fig. Fig. 38: 1984 250 (4.1L) 6-cylinder engine-2bbl federal, high and low altitude with manual or automatic transmission alternate

 


Click image to see an enlarged view

Fig. Fig. 39: 1984 250 (4.1L) 6-cylinder engine-2bbl federal, high and low altitude with automatic transmission alternate

 


Click image to see an enlarged view

Fig. Fig. 40: 1984 250 (4.1L) 6-cylinder engine-2bbl federal, high and low altitude with automatic transmission alternate

 


Click image to see an enlarged view

Fig. Fig. 41: 1984 250 (4.1L) 6-cylinder engine-2bbl federal, high and low altitude with manual or automatic transmission alternate

 


Click image to see an enlarged view

Fig. Fig. 42: 1984 250 (4.1L) 6-cylinder engine-2bbl federal and California, high and low altitude with manual or automatic transmission alternate

 


Click image to see an enlarged view

Fig. Fig. 43: 1984 250 (4.1L) 6-cylinder engine-2bbl California and low altitude with manual transmission

 


Click image to see an enlarged view

Fig. Fig. 44: 1984 250 (4.1L) 6-cylinder engine-2bbl California and low altitude with manual transmission alternate

 


Click image to see an enlarged view

Fig. Fig. 45: 1984 250 (4.1L) 6-cylinder engine-2bbl California and low altitude with manual transmission alternate

 


Click image to see an enlarged view

Fig. Fig. 46: 1984 250 (4.1L) 6-cylinder engine-2bbl California and low altitude with automatic transmission

 


Click image to see an enlarged view

Fig. Fig. 47: 1984 250 (4.1L) 6-cylinder engine-2bbl California and low altitude with automatic transmission alternate

 


Click image to see an enlarged view

Fig. Fig. 48: 1984 250 (4.1L) 6-cylinder engine-2bbl California and low altitude with automatic transmission alternate

 


Click image to see an enlarged view

Fig. Fig. 49: 1984 305 (5.0L) V8 engine-4bbl federal and low altitude with automatic transmission

 


Click image to see an enlarged view

Fig. Fig. 50: 1984 305 (5.0L) V8 engine-4bbl federal and low altitude with automatic transmission alternate

 


Click image to see an enlarged view

Fig. Fig. 51: 1984 305 (5.0L) V8 engine-4bbl federal and high altitude with automatic transmission

 


Click image to see an enlarged view

Fig. Fig. 52: 1984 305 (5.0L) V8 engine-4bbl federal and high altitude with automatic transmission alternate

 


Click image to see an enlarged view

Fig. Fig. 53: 1984 305 (5.0L) V8 engine-4bbl federal and high altitude with manual transmission

 


Click image to see an enlarged view

Fig. Fig. 54: 1984 305 (5.0L) V8 engine-4bbl federal and high altitude with manual transmission alternate

 


Click image to see an enlarged view

Fig. Fig. 55: 1984 305 (5.0L) V8 engine-4bbl federal and low altitude with manual transmission

 


Click image to see an enlarged view

Fig. Fig. 56: 1984 305 (5.0L) V8 engine-4bbl federal and low altitude with manual transmission alternate

 


Click image to see an enlarged view

Fig. Fig. 57: 1984 305 (5.0L) V8 engine-4bbl federal and low altitude with manual transmission alternate

 


Click image to see an enlarged view

Fig. Fig. 58: 1984 305 (5.0L) V8 engine-4bbl federal and low altitude with automatic transmission alternate

 


Click image to see an enlarged view

Fig. Fig. 59: 1984 305 (5.0L) V8 engine-4bbl federal and high altitude with automatic transmission alternate

 


Click image to see an enlarged view

Fig. Fig. 60: 1984 305 (5.0L) V8 engine-4bbl federal and low altitude with automatic transmission alternate

 


Click image to see an enlarged view

Fig. Fig. 61: 1984 305 (5.0L) V8 engine-4bbl federal and high altitude with automatic transmission alternate

 


Click image to see an enlarged view

Fig. Fig. 62: 1984 350 (5.7L) V8 engine-4bbl federal and low altitude with automatic transmission

 


Click image to see an enlarged view

Fig. Fig. 63: 1984 350 (5.7L) V8 engine-4bbl federal and low altitude with automatic transmission alternate

 


Click image to see an enlarged view

Fig. Fig. 64: 1984 350 (5.7L) V8 engine-4bbl federal and high altitude with automatic transmission

 


Click image to see an enlarged view

Fig. Fig. 65: 1984 350 (5.7L) V8 engine-4bbl federal and high altitude with automatic transmission alternate

 


Click image to see an enlarged view

Fig. Fig. 66: 1984 350 (5.7L) V8 engine-4bbl California and low altitude with automatic transmission

 


Click image to see an enlarged view

Fig. Fig. 67: 1984 350 (5.7L) V8 engine-4bbl California and low altitude with automatic transmission alternate

 


Click image to see an enlarged view

Fig. Fig. 68: 1985 260 (4.3L) V6 engine-4bbl federal and low altitude with automatic (A4) transmission

 


Click image to see an enlarged view

Fig. Fig. 69: 1985 260 (4.3L) V6 engine-4bbl federal and low altitude with automatic (A4) transmission alternate

 


Click image to see an enlarged view

Fig. Fig. 70: 1985 260 (4.3L) V6 engine-4bbl federal, high and low altitude with automatic (A4) transmission alternate

 


Click image to see an enlarged view

Fig. Fig. 71: 1985 260 (4.3L) V6 engine-4bbl federal low altitude with manual transmission

 


Click image to see an enlarged view

Fig. Fig. 72: 1985 260 (4.3L) V6 engine-4bbl federal low altitude with manual transmission

 


Click image to see an enlarged view

Fig. Fig. 73: 1985 260 (4.3L) V6 engine-4bbl federal high altitude with manual transmission

 


Click image to see an enlarged view

Fig. Fig. 74: 1985 260 (4.3L) V6 engine-4bbl federal high altitude with manual transmission alternate

 


Click image to see an enlarged view

Fig. Fig. 75: 1985 260 (4.3L) V6 engine-4bbl federal high and low altitude with manual (M4/M5 only) transmission alternate

 


Click image to see an enlarged view

Fig. Fig. 76: 1985 260 (4.3L) V6 engine-4bbl federal high altitude with automatic (A4 only) transmission

 


Click image to see an enlarged view

Fig. Fig. 77: 1985 260 (4.3L) V6 engine-4bbl federal high altitude with automatic (A4 only) transmission alternate

 


Click image to see an enlarged view

Fig. Fig. 78: 1985 260 (4.3L) V6 engine-4bbl federal, high and low altitude with automatic (A3 only) transmission

 


Click image to see an enlarged view

Fig. Fig. 79: 1985 260 (4.3L) V6 engine-4bbl federal high altitude with automatic (A3 only) transmission alternate

 


Click image to see an enlarged view

Fig. Fig. 80: 1985 260 (4.3L) V6 engine-4bbl California low altitude

 


Click image to see an enlarged view

Fig. Fig. 81: 1985 260 (4.3L) V6 engine-4bbl California low altitude alternate

 


Click image to see an enlarged view

Fig. Fig. 82: 1985 260 (4.3L) V6 engine-4bbl California low altitude alternate

 


Click image to see an enlarged view

Fig. Fig. 83: 1985 305 (5.0L) V8 engine-4bbl federal low altitude with automatic transmission

 


Click image to see an enlarged view

Fig. Fig. 84: 1985 305 (5.0L) V8 engine-4bbl federal low altitude with automatic transmission alternate

 


Click image to see an enlarged view

Fig. Fig. 85: 1985 305 (5.0L) and 350 (5.7L) V8 engines-4bbl federal low altitude with automatic transmission alternate

 


Click image to see an enlarged view

Fig. Fig. 86: 1985 305 (5.0L) V8 engine-4bbl federal high altitude with automatic transmission

 


Click image to see an enlarged view

Fig. Fig. 87: 1985 305 (5.0L) V8 engine-4bbl federal high altitude with automatic transmission alternate

 


Click image to see an enlarged view

Fig. Fig. 88: 1985 305 (5.0L) and 350 (5.7L) V8 engines-4bbl federal high altitude with manual transmission

 


Click image to see an enlarged view

Fig. Fig. 89: 1985 305 (5.0L) V8 engine-4bbl federal high altitude with manual transmission alternate

 


Click image to see an enlarged view

Fig. Fig. 90: 1985 305 (5.0L) V8 engine-4bbl federal high altitude with manual transmission alternate

 


Click image to see an enlarged view

Fig. Fig. 91: 1985 305 (5.0L) V8 engine-4bbl federal high altitude with manual (M4 only) transmission

 


Click image to see an enlarged view

Fig. Fig. 92: 1985 305 (5.0L) V8 engine-4bbl California low altitude with automatic transmission

 


Click image to see an enlarged view

Fig. Fig. 93: 1985 305 (5.0L) V8 engine-4bbl California low altitude with automatic transmission alternate

 


Click image to see an enlarged view

Fig. Fig. 94: 1985 305 (5.0L) V8 engine-4bbl California low altitude with automatic transmission alternate

 


Click image to see an enlarged view

Fig. Fig. 95: 1985 305 (5.0L) V8 engine-4bbl California low altitude with automatic transmission alternate

 


Click image to see an enlarged view

Fig. Fig. 96: 1985 350 (5.7L) V8 engine-4bbl federal low altitude with automatic transmission

 


Click image to see an enlarged view

Fig. Fig. 97: 1985 350 (5.7L) V8 engine-4bbl federal high altitude with automatic transmission

 


Click image to see an enlarged view

Fig. Fig. 98: 1985 350 (5.7L) V8 engine-4bbl federal high altitude with automatic transmission alternate

 


Click image to see an enlarged view

Fig. Fig. 99: 1985 350 (5.7L) V8 engine-4bbl federal low altitude with manual transmission

 


Click image to see an enlarged view

Fig. Fig. 100: 1985 380 (6.2L) V8 diesel engine-federal high altitude alternate

 


Click image to see an enlarged view

Fig. Fig. 101: 1985 380 (6.2L) V8 diesel engine-federal high altitude alternate

 


Click image to see an enlarged view

Fig. Fig. 102: 1985 380 (6.2L) V8 diesel engine-California low altitude

 


Click image to see an enlarged view

Fig. Fig. 103: 1985 380 (6.2L) V8 diesel engine-California low altitude alternate

 


Click image to see an enlarged view

Fig. Fig. 104: 1986 260 (4.3L) V6 engine-4bbl federal high and low altitude with automatic transmission

 


Click image to see an enlarged view

Fig. Fig. 105: 1986 260 (4.3L) V6 engine-4bbl federal low altitude with automatic transmission alternate

 


Click image to see an enlarged view

Fig. Fig. 106: 1986 260 (4.3L) V6 engine-4bbl federal high and low altitude with automatic transmission alternate

 


Click image to see an enlarged view

Fig. Fig. 107: 1986 260 (4.3L) V6 engine-4bbl federal high and low altitude with automatic transmission alternate

 


Click image to see an enlarged view

Fig. Fig. 108: 1986 260 (4.3L) V6 engine-4bbl federal high altitude with automatic transmission alternate

 


Click image to see an enlarged view

Fig. Fig. 109: 1986 260 (4.3L) V6 engine-4bbl federal high altitude with automatic transmission alternate

 


Click image to see an enlarged view

Fig. Fig. 110: 1986 260 (4.3L) V6 engine-4bbl California low altitude with automatic transmission

 


Click image to see an enlarged view

Fig. Fig. 111: 1986 260 (4.3L) V6 engine-4bbl California low altitude with automatic transmission alternate

 


Click image to see an enlarged view

Fig. Fig. 112: 1986 260 (4.3L) V6 engine-4bbl federal altitude with automatic transmission

 


Click image to see an enlarged view

Fig. Fig. 113: 1986 260 (4.3L) V6 engine-4bbl federal and California altitude with automatic transmission

 


Click image to see an enlarged view

Fig. Fig. 114: 1986 260 (4.3L) V6 engine-4bbl federal low and high altitude and export with automatic transmission

 


Click image to see an enlarged view

Fig. Fig. 115: 1986 292 (4.8L) 6-cylinder engine-1bbl Canada

 


Click image to see an enlarged view

Fig. Fig. 116: 1986 292 (4.8L) 6-cylinder engine-1bbl federal

 


Click image to see an enlarged view

Fig. Fig. 117: 1986 305 (5.0L) V8 engine-4bbl federal low altitude with automatic transmission

 


Click image to see an enlarged view

Fig. Fig. 118: 1986 305 (5.0L) and 350 (5.7L) V8 engines-4bbl California with automatic transmission alternate

 


Click image to see an enlarged view

Fig. Fig. 119: 1986 305 (5.0L) V8 engine-4bbl federal low altitude with automatic transmission alternate

 


Click image to see an enlarged view

Fig. Fig. 120: 1986 305 (5.0L) V8 engine-4bbl federal low altitude and export with automatic transmission alternate

 


Click image to see an enlarged view

Fig. Fig. 121: 1986 305 (5.0L) V8 engine-4bbl federal high altitude with automatic transmission

 


Click image to see an enlarged view

Fig. Fig. 122: 1986 305 (5.0L) V8 engine-4bbl federal high altitude with automatic transmission alternate

 


Click image to see an enlarged view

Fig. Fig. 123: 1986 305 (5.0L) V8 engine-4bbl federal high altitude with automatic transmission alternate

 


Click image to see an enlarged view

Fig. Fig. 124: 1986 305 (5.0L) and 350 (5.7L) V8 engines-4bbl federal high and low altitude and export with automatic transmission alternate

 


Click image to see an enlarged view

Fig. Fig. 125: 1986 305 (5.0L) V8 engine-4bbl federal high and low altitude and export with automatic transmission alternate

 


Click image to see an enlarged view

Fig. Fig. 126: 1986 305 (5.0L) V8 engine-4bbl export with automatic transmission

 


Click image to see an enlarged view

Fig. Fig. 127: 1986 350 (5.7L) V8 engine-4bbl federal low altitude with automatic transmission

 


Click image to see an enlarged view

Fig. Fig. 128: 1986 350 (5.7L) V8 engine-4bbl federal low altitude with automatic transmission alternate

 


Click image to see an enlarged view

Fig. Fig. 129: 1986 350 (5.7L) V8 engine-4bbl federal high altitude with automatic transmission

 


Click image to see an enlarged view

Fig. Fig. 130: 1986 350 (5.7L) V8 engine-4bbl federal high altitude with automatic transmission alternate

 


Click image to see an enlarged view

Fig. Fig. 131: 1986 305 (5.0L) and 350 (5.7L) V8 engines-4bbl California low altitude with automatic transmission

 


Click image to see an enlarged view

Fig. Fig. 132: 1986 350 (5.7L) V8 engine-4bbl federal

 


Click image to see an enlarged view

Fig. Fig. 133: 1986 350 (5.7L) V8 engine-4bbl federal with automatic (MD8 only) transmission

 


Click image to see an enlarged view

Fig. Fig. 134: 1986 350 (5.7L) V8 engine-4bbl federal with automatic (M40 only) transmission

 


Click image to see an enlarged view

Fig. Fig. 135: 1986 350 (5.7L) V8 engine-4bbl federal with automatic (MD8 only) transmission alternate

 


Click image to see an enlarged view

Fig. Fig. 136: 1986 350 (5.7L) V8 engine-4bbl federal alternate

 


Click image to see an enlarged view

Fig. Fig. 137: 1986 350 (5.7L) V8 engine-4bbl California

 


Click image to see an enlarged view

Fig. Fig. 138: 1986 350 (5.7L) V8 engine-4bbl California with manual transmission

 


Click image to see an enlarged view

Fig. Fig. 139: 1986 350 (5.7L) V8 engine-4bbl California with automatic (MD8 only) transmission

 


Click image to see an enlarged view

Fig. Fig. 140: 1986 350 (5.7L) V8 engine-4bbl California with automatic (M40 only) transmission

 


Click image to see an enlarged view

Fig. Fig. 141: 1986 350 (5.7L) V8 engine-4bbl California with automatic (MD8 only) transmission alternate

 


Click image to see an enlarged view

Fig. Fig. 142: 1986 350 (5.7L) V8 engine-4bbl Canada

 


Click image to see an enlarged view

Fig. Fig. 143: 1986 350 (5.7L) V8 engine-4bbl Canada with automatic (MD8 only) transmission

 


Click image to see an enlarged view

Fig. Fig. 144: 1986 350 (5.7L) V8 engine-4bbl Canada with manual transmission

 


Click image to see an enlarged view

Fig. Fig. 145: 1986 350 (5.7L) V8 engine-4bbl Canada with automatic (M40 only) transmission

 


Click image to see an enlarged view

Fig. Fig. 146: 1986 350 (5.7L) V8 engine-4bbl Canada with automatic (MD8 only) transmission alternate

 


Click image to see an enlarged view

Fig. Fig. 147: 1986 380 (6.2L) V8 diesel engine-federal high and low altitude

 


Click image to see an enlarged view

Fig. Fig. 148: 1986 380 (6.2L) V8 diesel engine-federal low altitude alternate

 


Click image to see an enlarged view

Fig. Fig. 149: 1986 454 (7.4L) V8 engine-4bbl federal

 

 
label.common.footer.alt.autozoneLogo