What should be checked first when performing a wheel alignment?

When performing a wheel alignment, the first step should be to check the suspension components. This is crucial because any worn or damaged suspension parts can significantly affect the alignment settings and overall vehicle performance. Suspension components, such as control arms, bushings, and struts, need to be in good condition to ensure accurate alignment measurements can be taken. If these components are not functioning correctly, they can lead to misalignment and affect the vehicle's handling, tire wear, and safety.

Although checking tire pressure, steering wheel angle, and brake fluid level are important for overall vehicle maintenance and safety, they do not directly address the initial requirements for a successful wheel alignment. Tire pressure must be correct for accurate alignment but is typically addressed after inspecting the suspension. Similarly, the steering wheel angle is a concern during the alignment process, but it comes into play after ensuring that all suspension parts are properly functioning. Brake fluid level is unrelated to wheel alignment and pertains more to the braking system's performance. Thus, starting with an evaluation of the suspension components ensures any necessary repairs can be made before proceeding with the alignment itself.