Auto Service World
Feature   February 1, 2004   by Auto Service World

Countertalk: Promoting Perfect Brake Service

There is little debate that the brake market is of paramount importance to the success of any auto parts wholesale operation, but it can have its challenges.

These challenges can take many forms: customer relations, profitability, technical issues. The fact that the market continues to evolve on all these fronts is perhaps one of the most interesting aspects of the brake market, and of the aftermarket at large. You would think that with the brake market being as important and brake jobs being so plentiful, there would be nary a technician who would not have the brake job down pat.

Yet every day, jobbers are faced with comebacks due to noise complaints and customers who still do not understand the difference between the various brake rotor and friction offerings. Too often, the focus of complaints is unduly on the parts being installed.

The reasons for this are varied, but at least partially due to the changing procedures for jobs, even from the original equipment service channel.

Honda, for example, has issued at least three changing procedures for Acura brake disc refinishing over the past few years. The subtle changes in the procedures are hard to notice. Most of the TSBs focus on the need to refinish the front rotors on the vehicle. The procedures, for example, require the use of a specific mounting kit for the on-vehicle brake lathe, as well as ensuring the opposite wheel’s brake rotor is effectively secured to prevent it from turning.

In the procedures, one set of cutters is recommended for most vehicles, while another is for others. Specifically, most Acura rotors are recommended to be cut with Kwik-Way cutters (PN KWI-109109223), while larger rotors, such as those on the 1986 to 1990 Legend, should be cut with 15-degree cutters.

Interestingly, in the latest recommendations, brake rotors must be refinished when newly installed, as well as when they are scored from use at pad replacement.

Here is an edited excerpt from service bulletin 00-37, published in August of 2001.

“Whenever you replace a front brake disc, you must refinish the new disc on the vehicle to avoid brake vibration.

“Put the transmission in neutral. If you are not using the power drive system, start the engine and let it warm up to its normal operating temperature so the idle speed will stabilize at its lowest rpm.

“Check for loose wheel bearings. You must correct for loose wheel bearings before you refinish the brake discs. If you do not, the brake lathe will not correct for brake disc runout, resulting in an uneven finish and brake pulsation.

“Remove the front wheels then reinstall the wheel nuts with flat washers to compensate for the removed wheel. Torque the wheel nuts to the required specification.

“Remove the caliper assembly. If you are not using the power drive system and the vehicle has TCS or VSA (traction control), make sure you install a brake pad spreader between the pads on the hanging caliper. Also, make sure that the system is turned off any time the engine is started. If the system is not turned off the brake may activate, causing the brake pads on the hanging caliper to hit each other, or the caliper pistons to fall out.”

The Acura situation is just one example of the increasing attention vehicles need to receive on the seemingly simple process of brake replacement. Failure to do so can often result in excessive noise or pedal pulsation, two of the most common consumer complaints.

The key point to all of this is that there is a lot to remember, which is in stark contrast to the general perception of brake work being a no-brainer.

Consequently, it is important for store managers and counterpeople to do what they can to minimize the number of problems their trade customers and the do-it-yourself customer can experience–or create themselves.

Right Brake Parts

One of the persistent issues regarding brake service, particularly in the DIY sales channel, is the selection of brake friction that is inappropriate for the way a consumer uses the vehicle.

This can take the form of specifying the least expensive brake parts you carry for a vehicle the customer uses to ferry his own children back and forth, to demanding severe-duty pads for the highway commuter. In either case, the friction materials are not going to deliver the desired level of performance.

Counterpeople and technicians should always make note of the vehicle’s usage pattern. This step is seldom taken at the garage level and counterpeople should be on the lookout for clues. Does the tech allude to the fact that the last pads didn’t last very long? Or did he say that they were great pads, lasted a very long time? Short or long pad life can point to friction materials that aren’t operating within their designed temperature range.

A similar approach is advisable when considering brake rotors. There are a variety of options for many fast-moving parts, but investigations have proven that not all are equal. White box rotors that are underweight and pads that wear too quickly are just two examples. Ultimately it is the decision of the customer, but it is up to the counterperson to accurately communicate the differences because they are not usually clear to the naked eye.

Most brake friction and rotor manufacturers have communication materials available and you should endeavour to offer these to your trade customers as well, as they may want to communicate key points to their customers.

Full Component Inspection

Under pressure to generate billable labour hours, some technicians may feel it necessary to take short cuts. Others aren’t even aware of the shortcuts they are taking.

Any proper brake job should involve the proper inspection of a variety of parts. Before disassembly, or at least before installing new parts, the worn friction should be inspected. Uneven wear can be an important clue to problems with the brake system. Front brakes that are wearing much faster than the rear may point to proportioning valve problems or rear brakes being out of adjustment. Excessive corrosion may also be an indicator that one or more brakes are not working properly.

Hardware is probably the most forgotten piece of the puzzle when it comes to proper brake service. In many cases, discolouration can go unnoticed and the nature of hardware’s role is that it may not be readily apparent just how much toll heat and fatigue have taken. In short, the hardware may look okay but actually be fried and require replacement.

Fluid Inspection and Replacement

Brake fluid is, as you likely know, hygroscopic, which means it attracts water. The more water content in the brake fluid, the worse it can handle the heat generated by the braking process. (In physics parlance, brakes convert the rotational energy of the brake disc into heat. That heat has to go somewhere.) The problem is that the water will continue to want to boil at 100 degrees C, while the temperatures experienced at the hot end of the brake system can exceed 150 degrees C.

DOT3 brake fluid with no moisture content boils at greater than 205 degrees C (400 degrees Fahrenheit as specified by the U.S. FMVSS Standard 116). The fluid in a 3-4 year old car with 3-4% water content in the brake fluid could boil at less than 150 degrees C.

Generally, the type of driving should influence when to change brake fluid. If the vehicle is used for towing, driving in mountainous regions, driven at high speeds or has ABS brakes, it would be best to change the fluid at 2% water content. All vehicles should have the brake fluid changed when the water exceeds 3%.

Generally, brake fluid will absorb 1% or more moisture per year of service life. A two-year-old car will have 2-3% water in the brake fluid. 2% water reduces the boiling point of DOT3 brake fluid by approximately 75 degrees C. With 2% water content, the boiling point of DOT4 brake fluid is reduced by 45 degrees C.

Caliper Inspection and Replacement

The symptoms of caliper failure include uneven or accelerated brake pad wear, presence of corrosion on one side of the brake disk (typically occurring on the inboard s
ide), instability under braking, or leaking fluid from one or more calipers. With the exception of corrosion on the inboard side of the brake disk, which is obscured by the brake backing plate, all other symptoms are easy to spot when the wheels are removed.

Technicians often focus on the friction materials only, ignoring the deteriorated condition of a caliper. What they may not be aware of is that after replacing worn hardware and inspecting a questionable caliper, it might have been more efficient if they had simply replaced the caliper with a semi-loaded unit. Most technicians have their preferences when it comes to friction, so fully loaded calipers are not often considered. The difference in time between inspecting and bench-rebuilding a caliper and just replacing it is significant and in their favour in terms of profit.

The perfect brake job is one that serves the needs of everyone: you the counterperson, the technician, the shop owner, and the owner of the car. The best way to ensure that this is the end result is to be continually vigilant about both the parts your customers are purchasing and the practices they are using to install them.

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