Braking, Steering and Suspension Systems
Brakes and hydraulics
The exam tests hydraulic braking, ABS, parking brakes, steering geometry and suspension inspection. Brake fluid is hygroscopic; use the specified DOT fluid and never mix DOT 4 with silicone DOT 5. Bleed from the farthest wheel to the nearest, keeping the reservoir topped up. Check pad thickness, disc runout with a dial indicator, caliper slide pins, hose condition and brake pipe corrosion. ABS warning lamps need a scan tool and wheel-speed sensor check. A spongy pedal means air or a leak; a low pedal can mean rear adjustment or a faulty master cylinder.
Steering and suspension
Know camber, caster, toe and steering axis inclination. Toe is the most common adjustment, but alignment should follow suspension or steering repair. Check ball joints, tie-rod ends, wheel bearings, strut mounts and springs before alignment. Power steering fluid level and belt condition matter; EPS needs electrical diagnosis, not fluid. Wheel balancing cures vibration at speed, while alignment cures tyre wear and pull.
Worked example
A car has a spongy brake pedal after pad replacement. Reason: the caliper pistons were pushed back and air entered, or the system was opened. Check for leaks, then bleed in the correct sequence, farthest wheel first, while keeping fluid above the minimum mark. If the pedal remains spongy, clamp hoses to isolate the master cylinder.
Traps
Do not push contaminated fluid back into the reservoir, reuse brake fluid, or align a car with worn tie-rod ends. Mixing DOT 5 silicone with DOT 4 can damage seals. A vibration after tyre change is often balance, not alignment.