The air cleaner has a dual purpose. It not only filters the air going to the carburetor, but also acts as a flame arrester if the engine should backfire through the carburetor. The engine should never be run without the air cleaner installed unless an engine maintenance procedure specifically requires the temporary removal of the air cleaner. Operating a car without its air cleaner results in some throaty sounds from the carburetor giving the impression of increased power, but this will only cause trouble. Unfiltered air to the carburetor will eventually result in a dirty, inefficient carburetor and engine. A dirty carburetor increases the chances of carburetor backfire and, without the protection of an air cleaner, an underhood fire becomes a very real danger. The air cleaner assembly consists of the air cleaner itself (the large metal container or housing that fits over the carburetor), the element (paper or polyurethane) contained within the housing, and the flame arrester located in the base of the air cleaner. If your car is equipped with the paper element, it should be inspected at its first 12,000 miles, rechecked every 6,000 miles thereafter, and replaced after 24,000 miles for 1974 and earlier vehicles. For 1975 and later vehicles, air cleaners should be replaced at 30,000 mile intervals if the paper type (V6 and V8), and 15,000 miles if the oil wetted type (inline six). Inspections and replacements should be more frequent if the car is operated in a dirty, dusty environment. When inspecting the element, look for dust leaks, holes or an overly dirty appearance. If the element is excessively dirty, it may cause a reduction in clean air intake. If air has trouble getting through a dirty element, the carburetor fuel mixture will become richer (more gas, less air), the idle will be rougher, and the exhaust smoke will be noticeably black. To check the effectiveness of your paper element, carefully remove the air cleaner assembly and, if the idle increases, then the element is restricting air flow and should be replaced. If a polyurethane element is installed, clean or replace it every 12,000 miles. If you choose to clean it, do so with kerosene or another suitable solvent. Squeeze out all of the solvent, soak in engine oil, and then squeeze out the oil using a clean, dry cloth to remove the excess. The flame arrester, located at the base of the carburetor, should be cleaned in solvent (kerosene) once every 12,000 miles.
REMOVAL & INSTALLATION
See Figure 1
For most vehicles, the filter element is easily accessible by removing the cover from the air cleaner assembly.
- Loosen the wing nut(s) at the center of the air cleaner cover, and if applicable, the clamp fasteners along the cover's edge.
- Remove the cover from the air cleaner assembly, then remove the air cleaner element from the housing.
- If necessary, disconnect the air intake hose and, if applicable, the heat stove and/or vacuum line(s), from the air cleaner housing and remove the housing from the vehicle.
- If removed, position the air cleaner housing on top of the carburetor or throttle body, then connect the air intake hose. If applicable, connect the heat stove and/or vacuum lines.
- Install the air cleaner element to the housing, then position the cover onto the assembly.
- Secure the cover using the clamp fasteners and/or wing nut(s).