* Brake Booster: A large, usually round canister near the firewall, often with a single, fairly thick vacuum line.
* Distributor (if equipped): On vehicles with distributor ignition, a smaller vacuum line usually connects to the distributor advance mechanism.
* Throttle Body: Several lines may connect here, depending on the engine and features. These often control things like the EGR valve, and the air intake system.
* EGR Valve: A valve that recirculates exhaust gases, typically located on the intake manifold.
* HVAC System (Heater/AC): Lines control the vacuum-operated actuators for things like blend doors and vents. These are usually found near the firewall behind the glove compartment and sometimes under the dash.
* Transmission (if applicable): Some automatic transmissions used vacuum for shift modulation.
* Various Emission Control Components: Depending on the emission system, several smaller vacuum lines might connect to components under the hood.
To find them: You'll need to consult a repair manual specific to your 1994 Chevy S-10's engine (e.g., 2.2L, 4.3L V6). These manuals will have detailed diagrams showing the vacuum line routing. A visual inspection with the engine compartment clean is crucial. Look for small diameter lines, often black or colored tubing. Follow them from the components listed above to trace their paths.
Important Note: Because the routing can vary slightly depending on options and condition, relying solely on general descriptions is risky. A repair manual is strongly recommended to avoid misconnections that can negatively impact your vehicle's performance or safety.
