A5 Brakes
Review Answers
Reading Your Results: A5 Brakes, Test 1
A score by itself only tells you whether you passed. What follows is how to read the questions you missed on this test. A5 divides cleanly into two halves that fail in different ways, and knowing which half a symptom belongs to is most of the diagnosis.
If you missed the pedal feel questions
Pedal complaints are a language, and this test expects you to read them. A pedal that sinks slowly under steady pressure with no external leak is fluid going somewhere internally, which means the master cylinder is bypassing past its cups. A pedal that is low on the first application and rises on the second is something moving away between stops, whether that is excess rotor runout knocking the pistons back or a loose wheel bearing letting the assembly wobble. A pedal that will not release, or brakes that drag after the pedal comes up, means pressure is being trapped rather than lost, so the compensating port, the pushrod adjustment, or a return spring is holding the system closed. Name what the pedal is doing before you read the options, because each behavior points at a different part of the hydraulic circuit.
If you missed the questions built on a measurement
Three questions here give you readings against a published figure, and each is asking whether you know what the specification is protecting.
If you missed the electronic brake control questions
The ABS, traction control, and stability control questions on this test are about which sensor tells the module what. Wheel speed sensors report how fast each wheel is turning. The yaw rate sensor reports how fast the vehicle is rotating about its vertical axis, which is what the module compares against the driver's steering input to decide whether the vehicle is going where it was pointed. Traction control applies a brake at a spinning drive wheel and may also reduce engine torque, while stability control brakes individual wheels to correct the vehicle's path. A module replacement usually requires configuration before the system will work, which is why a configuration code after a module swap is not a fault in anything you can measure.
If you missed the EXCEPT and LEAST likely questions
Four appear on this test, and missing more than one is a reading habit rather than a knowledge gap. Work out what the three real causes share before you look for the odd one. On the parking brake question, three answers all break the mechanical path between the lever and the shoes, and one is a hydraulic fault that the parking brake does not use. On the caliper piston question, three answers all mean the piston or its bore is damaged or corroded, and one is a normal condition that a proper retraction procedure handles. Naming the shared trait first turns a four-way guess into a single check.