Brake repair is a service most of us won’t want to put off when our repair shop recommends it. Safe operation of our vehicle requires that brakes are working correctly and able to stop us completely within a safe distance. Brakes on today’s vehicles are complex with anti-lock braking and other computerized components. These computers rely on correct mechanical brake functions so the electronics can do the job they’re designed to do.
Brake system components operate in harsh dirty conditions and function under extreme temperatures and pressures. At AutoTranz Repair in Boise, we use quality Napa brake repair parts and follow professional repair procedures so we know our customers’ vehicles will be able to stop safely no matter what type of situation.
The goal of this article is to give you some information to facilitate clear communication about your brake repair needs when you call us with a problem.
Common brake system problems
The most common brake system complaint auto repair shops get is about brake pulsation. While more annoying than unsafe, it’s still one of the most common reasons for brake repair on today’s cars, trucks and SUVs.
Fixing this problem is not hard, but there are several factors that influence what brake repair procedures should be taken to correct the condition.
When correcting brake pulsation the mechanic must determine the cause of the customer’s complaint. There are a number of reasons or causes for brake pulsation:
- The brakes were overheated which warped the brake rotors
- Brake calipers are hanging up and causing rotor warping
- Pulling a trailer that caused overheating and rotor warp
- Rotor warp over time from normal driving
- Loose wheel bearings
A second common brake system complaint repair shops are asked about is brake warning lights. Almost every new vehicle built in the last ten years has anti-lock brakes. These brake systems are controlled by computers and use sensors to monitor wheel speed to determine when the anti-lock brakes should activate. Brake sensors and their connecting wires must flex over every bump the vehicle travels. This continuous movement wears the wires internally and eventually they break. This sets a code and the computer turns on the brake warning light.
A third common brake repair complaint auto repair shops hear relates to the fluid within the braking system. A car owner states:
- I keep losing brake fluid in the brake master cylinder?
- My brake pedal slowly fades to the floor after stopping?
Now that we have listed the main complaints about brake repair, lets talk about how these problems can be repaired. While we won’t cover every repair situation, we will address how auto repair shops will fix these common problems.
Brake pulsation is that annoying undulation that happens when braking to slow or stop. The cause is one or more rotors being warped, meaning the two sides of the rotors are not parallel and the rotor thickness varies at different places around the rotor. This unevenness pushes on the brake parts and the vehicles suspension, which causes the vibration or undulating you feel when applying the brakes.
Three ways to fix brake pulsation problems
- Have the warped brake rotors turned on a lathe to make them straight
- Replace warped rotors
- Repair loose wheel bearings so brake rotors don’t wobble
The first procedure to eliminate brake pulsation involves turning the warped rotors. This process can happen with the rotors on or off the car. It removes thin layers of metal from the rotor surfaces with the goal of restoring both sides of the rotors to an even or “true” state with no thickness variation. This is normally a good fix that eliminates noticeable pulsation as brake pads can once again apply even pressure to the rotors during stops.
Since this turning process removes metal, the rotors lose thickness and are more likely to warp again when heated by normal braking. Picture the differing amounts of flame needed to light a thin versus a thick piece of wood on fire. While less flame lights a thin piece, more is needed to light a thick piece of wood.
The same concept can be applied to thick versus thin rotors and the amount of heat that produces a change. Auto owners should consider that since thinner rotors warp sooner than new “thicker” rotors, having rotors turned to correct pulsation will likely results in the need for brake repair sooner than if new rotors are installed.
That brings us to the second method to fix brake pulsation, which is rotor replacement. A repair shop that provides rotor-turning services may measure the rotor and determine they are so thin that not enough metal remains to allow removal of more during turning process. This means the rotors must be replaced. With the price of replacement rotors dropping and the undesirable tendency of turned rotors warping sooner than a replacement, many repair shops today don’t bother repairing warped rotors. They simply provide a quote for replacing rotors to fix a brake pulsation.
The third brake repair method to fix pulsation is to replace loose wheel bearings. Worn bearings can’t hold the rotor secure enough to keep it straight and cause uneven rotor wear that gets progressively worse with increased mileage. Even if brake rotors are turned or new rotors are installed, there can still be pulsation with loose wheel bearings.
Brake warning light repairs start with the technician reading the code that caused the light to display. After the code is read, a diagnostic procedure is followed to identify the component or wiring problem responsible for the failure that set the code.
Frequently, the intermittent operation of a wheel speed sensor is what sets a code. The code will identify which sensor is responsible and then the tech will usually be directed to measure the resistance of the sensor. If the resistance is not within specification, the sensor will be replaced.
When sensor wiring is the offending culprit, the dash warning usually happens under extreme use as with going over bumps or curbs in a driveway. These conditions stretch the wiring enough to cause the failure.
Depending on the brake system failure code, there could also be problems with a brake module or solenoids within the module. In the case of a speed sensor fault, the code will lead the tech to the diagnostic charts and have them complete tests to isolate the reason for the fault code. Remember, when these failures are intermittent, they can be hard to diagnose because the system may test correctly while in the shop.
Hydraulic brake fluid leaks can be internal or external. External leaks will drip fluid on the ground or under the dash on the driver’s side near the feet. Internal leaks can’t be seen, but they are felt, usually in the form of a brake pedal that falls slowly while at a stop sign.
If your vehicle is losing fluid, no matter where, you should talk to your repair shop about how best to deliver your vehicle to them for diagnosis of the problem without compromising your safety.
External fluid leaks are corrected by replacing the component that is leaking. Here is a list of components where leakage is possible:
- Brake master cylinder
- Drum brake wheel cylinder
- Brake caliper
- Flexible brake hose
- Rigid brake line
Internal leaks are usually in the master cylinder, but it is possible to have a caliper or brake cylinder leaking internally. This basically means that hydraulic fluid is bypassing the rubber seals inside the cylinder so the pressure is not holding.
Brake repair services summary
We’ve shared some brake terminology and brief details about common brake repair services for brake pulsation, brake warning light on, and brake fluid leaks. Our goal in presenting the information above is to help increase understanding and facilitate communication when a specific service or repair is recommended to correct your braking problem.
Our commitment is to clearly communication with you about your vehicle’s brake problem. This includes an explanation for the recommended brake repair service along with a detailed estimate of the repair cost. No work starts until you are confident enough with our assessment and estimate to authorize the repair. We also offer comparison pricing between precision rotor turning and replacement with quality new parts to help you stay within your vehicle repair budget.
At AutoTranz Repair in Boise, every brake repair our professional technicians complete will give you the satisfaction of a safe smooth stop when you need it. We stand behind the Napa national warranty on all our brake repairs.
Call us today (208) 853-1200 if you have any questions. If you want a free brake inspection you can request an appointment with a date that works for your schedule and we will get back with you to verify the appointment.