By Keith Miller
Questions — I get asked a lot of them, many times the same question from multiple people. For a change of pace, I’ll start adding a few of these to our newsletters.
Often people just need an explanation of services performed or why a part failed. We’ll take the time to explain the reason for a repair, while not baffling you with technical jargon.
Can I just put new brake pads on my car? Do I need to install new rotors?
Since asbestos products were taken off the market years ago, our brake pads have become a heavier mix of carbon and metallic fibers, which are much harder compounds compared to the softer asbestos. Performance brake pads are dense and firm, accelerating wear on brake rotors. Most rotors are made of high-grade steel. Even these good steel rotors wear from heavy contact with the pads, so we typically won’t replace pads without replacing rotors. Occasionally a rotor can be “turned”; this refers to machining metal off the surface of the rotor to flatten the contact area. Brake component manufacturers have strict machining limits, and some rotors are not allowed to be machined according to the manufacturer. Rotors that have been machined are even more susceptible to warping and pulsating due to mass being removed.
If you attempt to replace pads without doing anything to the rotors, you’ll tend to get a loud brake squeal from the hard pads chattering on the imperfect surface of the rotor. It can give you the feeling of nails on a chalkboard — not what we want coming from your favorite car.
Most luxury, sports, and exotic vehicles have a brake wear indicator, which is simply a sacrificial carbon block with a wire or series of wires embedded in it. As pads wear, this block wears away, until the embedded wire is exposed and illuminates a brake light on your dash. These wires can break prematurely, but are usually a reliable indicator. They need to be replaced with every brake pad change.
What types of work can you do?
You may recognize some of the general work we do: brakes, tires, and recommended maintenance. What may surprise you is our ability to do more complex maintenance, such as engine repair or replacement, Porsche IMS bearings, turbo replacement, restorative maintenance, or clutch and transmission replacement.
In recent months, we have removed an Audi Q7 engine and replaced it with a factory remanufactured engine, replaced several Porsche IMS bearings, and removed an old MG TD drivetrain to reseal and paint before reinstalling. In addition to removing the entire powerpack from a BMW 335 to replace turbos, we’ve seen our share of clutch and transmission work too. We should also mention we’ve used a Roock-modified Porsche Boxster donor car to transform a mild-mannered standard Boxster into a spirited driver. All these services can be handled in-house, so let us know if you have specific needs.
What is so special about road force balancing?
When you think of driving a nice car, “smooth ride” is often used to describe the feel of cruising at highway speeds. Road force balancing is an additional act in balancing the tires, where a roller wheel is pressed against the tire to simulate the force of the road pushing back against the tire. Computerized sensors in the roller give feedback that allows us to match the light spot of the tire to the heavy spot on the wheel for optimal balancing. It’s an extra step in the balancing process that is imperative to smooth operation. Not all places offer it, and not all technicians will take the time to do it. At SweetCars, it’s been part of our practice for six years on every tire.
Feel free to submit your questions via email or voice mail. I’ll be happy to reply personally or answer them here.