Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Air Injection System - CALIF: Description
The air pump air injection system is designed to reduce hydrocarbon (HC) and carbon monoxide (CO) content of exhaust gases by injecting a controlled amount of compressed air into the exhaust manifold.
System components and application vary between models. Typical components of the system are: a belt-driven air pump with integral relief valve, air control valve with relief valve, air by-pass valve, water thermo valves, vacuum delay valve, check valve and various hoses and piping. A heat hazard warning system is used on GLC Wagon models to prevent exhaust system overheating.
Use the Manual With the Right Hardware
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.
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