How Is a Brake Diagnostic Test Different From an Inspection?

A brake inspection is a hands-on check of the parts that wear: pads, rotors, calipers, hoses and brake fluid. A brake diagnostic test checks the electronic side, reading fault codes and live sensor data from the anti-lock brake system (ABS) with a scan tool. Most cars only need the inspection on a regular schedule. Once the ABS or brake warning light comes on, a scan is the only way to read the fault behind it. At Mango Automotive The Heights on Comanche Rd NE, when a brake warning light is on we pull the ABS codes before recommending any parts.

What happens during a brake inspection?

The wheels come off so the technician can see and measure each corner. During a brake inspection at Mango, we measure pad thickness, check rotor surface and thickness, look at caliper movement and hose condition, and test the brake fluid for moisture. A road test covers both light and hard braking. If the pedal feels soft, we pressure-test the master cylinder and hydraulic lines.

An inspection tells you how much life is left in the parts you can see and measure. It does not read the brake system's electronics.

What happens during a brake diagnostic test?

The technician connects a scan tool to the vehicle's diagnostic port and reads any trouble codes stored in the ABS module. On many vehicles the traction control and stability control systems share the same wheel speed sensors, so their codes are checked too. Live data from each wheel speed sensor shows whether every wheel is reporting a sensible speed.

ABS codes need a scan tool that can communicate with the brake module. A basic engine code reader may not see them at all.

Brake inspection vs. brake diagnostic test at a glance

• What it checks. Inspection: pads, rotors, calipers, hoses and fluid. Diagnostic test: ABS codes, wheel speed sensors and related electronic faults.
• Tools. Inspection: a lift, measuring tools, a fluid moisture test and a road test. Diagnostic test: a scan tool that can read the brake module.
• Usual reason. Inspection: routine maintenance, brake noise, a soft pedal or a pull. Diagnostic test: an ABS, brake or traction control warning light.
• What it can miss. Inspection: electronic faults that leave no visible wear. Diagnostic test: worn parts that have not triggered a warning yet.

Why an ABS light deserves a scan

When the ABS light stays on, the anti-lock function may not be working, even though ordinary braking usually still does. That matters. In its long-term study of anti-lock brakes, NHTSA found that ABS reduced involvement in nonfatal crashes by 6 percent in passenger cars and 8 percent in light trucks, a group that includes pickups, SUVs and vans ( NHTSA, DOT HS 811 182, 2009). A light that stays on means that protection may not be there when you need it.

A red brake warning light is a different signal. It can mean the parking brake is still on, the brake fluid is low or there is a hydraulic problem. If it stays on after the parking brake is fully released, or the pedal feels different, have the brakes checked before you keep driving.

Which check do your symptoms point to?

• ABS or traction control light on: diagnostic test, to read the stored code.
• Red brake warning light on: inspection of the fluid level and hydraulics first, plus a scan if the vehicle has stored a code.
• Squealing or grinding from the wheels: inspection. Grinding can mean the pads are worn down to metal. Our post on squealing noises in your car covers other sources of the sound.
• Soft, spongy or sinking pedal: inspection right away. If the pedal sinks toward the floor, stop driving and have the car towed or checked where it is.
• Pedal pulsing in normal stops: inspection. This usually points to the rotors. A rapid pulse during a hard stop on a slick road is the ABS doing its job.
• Pulling to one side when braking: inspection first, since a sticking caliper or uneven pad wear can cause it, and a scan if a warning light is also on.

Common questions

How much does a brake diagnostic test cost?

It depends on the vehicle and on what the code points to. At Mango we show you what the testing found and you approve the work before any repair begins.

Can I keep driving with the ABS light on?

Normal braking usually still works, but the anti-lock function may be off. Leave extra room to stop and have it scanned soon. If the red brake light is on as well, have the brakes checked before you drive further.

Brake inspection and ABS diagnostics in Albuquerque's Northeast Heights

Mango Automotive The Heights is at 10340 Comanche Rd NE, with easy access from Wyoming Blvd, Eubank Blvd and Montgomery Blvd. We find the cause before we quote the fix, you approve the work before it starts, and eligible brake repairs are backed by our 5-year/60,000-mile warranty. Call (505) 299-5011 or book at The Heights.