RANT: Commercials For DIY Brake Jobs From Parts Stores

You are watching the game and a commercial for a national auto parts chain comes on the screen. If it is a live game, you can’t skip it. In just 20-30 seconds they try to make comparisons between wrestling or skinning a bear to replacing the brake pads on a car. I am all about empowering males to get out into the garage and doing something. But, do something besides brakes, please, have them replace an air filter or change a headlight. JUST STAY THE HECK AWAY FROM THE BRAKES.

Or, maybe buy the other 30 seconds to run disclaimer like drug commercials:

“If you have a brake job last more than four hours, please consult a mechanic. Performing your own brake job may result in longer than normal stops, rear end collisions, noise, bad smells, stains on the garage floor, loss of fingers, skid marks on your seats and possibly a fatal accident. Please see you local tool store for the correct torque tools and thread locking compounds. Failure to use these components may result in parts lose and death.”


RANT: Skipping Measurements on Rotors

brake pulsationYou may think that you are not paid to measure thickness and runout, but are you paid for a comeback?

Even if you install a new rotor, you are setting yourself up for a comeback if you do not measure using a micrometer or dial indicator. Even a “perfect” premium rotor will have runout if it is put on a flange with runout or corrosion.

Installing new rotors is not a way to avoid having to use a micrometer or dial indicator. For every brake job, you should always measure for runout (rotor and flange) and the dimensions of the rotor before brake service is performed.

After the rotor is resurfaced or a new rotor is installed, the rotor should be measured for runout when it is installed on the vehicle as a quality control method. A new rotor could have excessive runout when it is installed on the vehicle due to a stacking of tolerances.

You may think that installing new rotors eliminates the possibility of a comeback. However, this myth creates more comebacks that it solves. These comebacks often start with blaming the new pads, and ends with the customer having to return a second or third time until someone pulls out a dial indicator and micrometer.

Let’s say a vehicle had .003” of lateral runout when measured at the outside face of the rotor. If this vehicle is riding on 205/55R16 tires, in one mile, the high-spot with .003” of runout goes past the caliper approximately 836 times. Over 6,000 miles, that spot on the rotor will go past the pads more than 5 million times. Every time this spot passes the pads, a little bit of the rotor’s material is removed. Over the course of those 5 million revolutions, enough material is removed to create a thickness variation that can be felt by the driver.
This is why it is critical to measure thickness and runout in a brake rotor and wheel flange even if new rotors are going to be installed.

RANT: People Who Install Track Pads on Daily Drivers

brakes_1I recently had a friend come to me with a set of brake pads for his BMW M3 for me to install. These were super aggressive pads that belonged on a race car and not a street car. I knew if I installed them I would be replacing them in a week or two because of the noise.

“What do you dislike or like about your current brakes?” I asked. He said he was not having problems or issues. It was the usual glory story from a forum where a guy installed them on his car and they made the vehicle stop on a dime or improved their lap time. He had to have them because they would “bite,” what ever that means…

I explained in plain and simple terms, a friction material with a higher coefficient of friction or µ will use less pedal pressure to stop the vehicle. With lower pedal pressures, the driver’s right foot may be thinking, “These are really great brakes compared to my old friction material.” But, it goes much deeper than that when it comes to true high-performance brake pads.

High performance is an over used phrase in brake pad catalogs because it is both subjective and relative. The litmus test for most high-performance pads is if the friction material has the characteristics to meet or exceed the OEM specifications for coefficient of friction and/or temperature.

One defining characteristic of some high-performance pads is the backing plate. Backing plates can play a distinct role in creating a positive pedal feel and stopping ability. The backing plate creates a foundation for the friction material that must be stiff and stable. If a backing plate is flexing, the friction material is not in full contact with the rotor. This can cause longer stops, a softer brake pedal, and it increases the potential for unwanted noise.

High-performance backing plates might use thicker and better quality steel, but that is impossible to see. One visual clue is on the back of the pad. Look at the holes for integral molding (IM) on the backing plate. These holes might be in a different configuration than a conventional pad. With fewer or a different configuration of holes, the manufacturer can make a stiffer foundation for the friction material.

Some pads use backing plates without any holes. Without the IM holes, the backing plate is theoretically stiffer. These backing plates use mechanical attachment methods to attach the material to the pad. In some cases, the backing plate may use special surface treatments in conjunction with an adhesive to eliminate the IM holes.

Fade resistance is another feature of high performance pads. Brake fade can be caused by the out-gassing of the pad that creates a boundary layer of gasses between the pad and rotor. This happens when water, uncured resins and other components are heated to the point that they generate gases. The gases create a barrier between the pads a rotor that prevents friction from being generated.

I told him they may be near impossible to deal with on the street because they do not reach the optimal operating temperature during normal driving. But, when they are warm, the braking performance of the vehicle is greatly increased. Also, these high µ friction materials have superior resistance to fade. Noise? Some of these friction materials can produce a lot of noise when they are applied and even when they are not. But, they are made for racetracks and not the street.

I installed the pads. After two weeks he gave me a call and said that his wife was going to divorce him because of the pads. He said he could never use the race pads to their full potential. We went with a pad that had better cold torque stopping ability. These were designed for the weekend warrior. These pads will not have the same overall coefficient of friction the racing brake pad, but at lower temperatures they will generate more brake torque and be more consistent as temperatures increase. His wife was happy.


RANT: OES+OEM=BS When it Comes to Brake Pads

OEM Brake Pad Coupon
You can’t make judgments on brake pads or other parts, or making blanket statements on what pads are better. But, there are some confusing marketing messages used by both aftermarket and OE marketing people when it comes to brake pads.

For the past 20 years, the phrase “Meets or Exceeds OE ______” has been used by the replacement parts industry to the point where it has lost any and all meaning. Some companies even use it to sell snake oil. But, it is still part of the collective conscious that OE or OEM equals quality.

When it comes to OES (Original Equipment Supplier) pads, chances are it will not be the same pad, or even manufacturer as the pads installed at the factory. It will be close to the OE pad because, in some cases, the OE is willing to share design and engineering specifications with the OES supplier. But, more often than not the pad is selected by an accountant.

Most shops will tell you they buy brake pads from the dealer if the customer specifies it or if they have confidence in the dealer’s product (which is rightly deserved in some cases). Some of these OES pads are manufactured by many of the advertisers you see in this magazine.

But, the most irritating aspect of these second-line pads is when local dealers try to pass off $99 “pad slaps” as “approved service” with “genuine” parts.

Most of the marketing and advertising at the local level by the dealers makes it sound like the consumer will drive out of the service department with a new car for $99. It is a marketing ploy that plays on the assumptions and ignorance of the consumer. Also, it is hurting the automotive service industry as a whole.