Following are 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 vehicle be equipped with a different engine from the vehicle's original equipment, refer to the diagrams below for the same or similar configuration.
If you wish to obtain a replacement emissions label, most manufacturers make the labels available for purchase. The labels can usually be ordered from a local dealer.
| Fig. 1: Vacuum hose routing — 1979–80
Federal vehicles (all models)
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| Fig. 2: Vacuum hose routing — 1979 California
vehicles (all models)
|
| Fig. 3: Vacuum hose routing — 1980 California
vehicles (all models)
|
| Fig. 4: Vacuum hose routing — 1981–83
Federal vehicles (all models)
|
| Fig. 5: Vacuum hose routing — 1981–82
California vehicles (all models)
|
| Fig. 6: Vacuum hose routing — 1983 California
vehicles (all transmissions) & 1984 California vehicles with manual transmission
|
| Fig. 7: Vacuum hose routing — 1984 California
vehicles with automatic transmission
|
| Fig. 8: Vacuum hose routing — 1984 Federal
vehicles with manual transmission
|
| Fig. 9: Vacuum hose routing — 1984 Federal
vehicles with automatic transmission
|
| Fig. 10: Vacuum hose routing — 1986 Federal,
California and Canadian B2000 models
|
| Fig. 11: Early rotary engine vacuum diagram
|
| Fig. 12: 1972–74 Piston engine PCV & Evaporative
systems
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| Fig. 13: 1975–78 Piston engine PCV system
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| Fig. 14: 1975–78 Piston engine evaporative system
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| Fig. 15: 1974–77 Rotary engine PCV system
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