Undercar

  • Ever hear of the government's Corporate Average Fuel Economy (CAFE) regulations? First enacted by Congress in 1975 in response to the oil embargo of the era, it sets fuel economy standards for passenger cars and light trucks sold in the United States
  • For many drivers, parking brakes are an afterthought — if they're thought of — and that's not good. This too-often overlooked system serves an important purpose. That purpose has nothing to do with emergencies; banish the term "emergency
  • I have trained and placed quite a few technicians in the past six years, and up to this point, I've managed to place all my graduates in dealerships or independent shops. I like to see my guys do well. They call me sometimes for advice, sometimes to
  • While a few high-dollar models' electric parking brakes do away with conventional parking brake cables, it's going to be a long time before servicing those cables, and the mechanisms that pull them won't be standard operating procedure. So let's look
  • Servicing dual-mass flywheels is a challenge. Resurfacing or rebuilding a dual-mass flywheel (DMF) usually isn't an option. "Sticker shock" frequently results in replacement with a less expensive, solid flywheel. What about inspection and re-use? Her
  • Truth or dare...true or false...tire pressure monitoring system (TPMS) repair is now as commonplace and necessary to understand and deal with as a standard oil change. I remember my first GM Computer Command Control class back in 1980.
  • When as Little as .001 INCH of lateral rotor runout can be enough to lead to disc thickness variation (DTV), it's crucial that rotors run true when they leave the shop. After all, once DTV has developed, drivers feel it as pedal pulsation, a leading
  • Rodney Dangerfield had nothing on parking brakes: They "don't get no respect" either. Even in modern vehicles, rear-drum parking brakes are essentially straight out of the 1960s (or before.) And motorists regularly "diss" them, too – not a wise
  • When our VAT40 died at the Ford/Jeep dealer, the shop foreman and service manager opted for what appeared to be a suitable succedaneum. The new tester came off the MAC tool truck for a cash exchange of about $1,700.
  • Shops generally get involved in three types of vehicle inspections: emissions (I/M) inspections, state-mandated safety inspections and customer requested inspections. All three types of inspections share some common elements, and all three should ben
  • The average refrigerant charge in an older A/C system could be three pounds or more. Most passenger cars and light duty trucks today carry less than 20 ounces of refrigerant — barely more than one pound. So is efficient leak detection important
  • From run-flat tires to the implementation of tire pressure monitoring systems (TPMS), there's a lot of information today's technicians need to learn about. Even if you're not servicing tires, learning about them will help your bottom line, as many co
  • What are the challenges in designing a NASCAR brake system? A vehicle in motion accumulates kinetic energy proportional to its mass and to the square of its speed. So to stop that vehicle or to even just slow it down, that energy has to be transferre
  • Without spouting unnecessary scientific terms, let's loosely define the first and second laws of thermodynamics by saying that to begin with, heat must be generated by something at the expense of something else and then follow that to say heat moves
  • For an engine to be efficient, it must have the proper exhaust flow to get rid of all the products of the combustion process. The air that is taken in through the intake has to be expelled after being used, and there's only one way out: the exhaust s
  • Onboard diagnostic (OBD) systems were pioneered and refined in gasoline engines, but now this technology has taken a firm hold in the diesel engine world as well. As of the 2007 model year, all diesel-powered vehicles rated at less than 14,000-pound
  • Most 21st Century Brakes look much like 20th century brakes, but then the new century is still young. Besides, looks don't always tell the full story.
  • Technology Never Quite stands still. Changes aren't always as revolutionary as the introduction of antilock braking, electronic calipers or ceramic rotors.
  • To many, electrically operated parking brakes are the answer to a question nobody asked. These systems replace parking brake cables and the lever or pedal with a switch, a processor, wiring and actuators. They started coming into common use about six
  • Antilock braking may seem relatively new, but it first was used in aircraft, because the kind of pedal-pumping action once commonly practiced by expert automobile drivers is difficult or impossible in an airplane. The first systems, say some sources,