Gary Goms, Author at UnderhoodService - Page 23 of 25
Disc Brake Calipers

Disc brake calipers come in many sizes and configurations, including fixed-caliper, multi-piston designs, and the more modern floating-caliper, single piston designs that may also contain a mechanically actuated parking brake. Needless to say, disc brake calipers have undergone a series of design changes that continue to make them more adaptable to late-model import vehicle applications.

Marketing Mufflers: Muffler Replacements Are a Fast, Easy Way to Improve Your Shop’s Bottom Line

Have muffler inspections become a low-priority undercar service in your shop? With the introduction of stainless-steel exhaust systems into the import market, it’s easy to forget that muffler and related exhaust parts sales are still a lucrative service that can enhance any profit and loss statement. Muffler replacements can be profitable at any skill or

Diagnostic Dilemmas: Navigating OBD II Scan Tool Diagnostics

Although some hybrid OBD I/OBD II versions existed as early as 1994, the current version of OBD II was introduced in 1996. Because OBD II is a scan tool-based diagnostic system, diagnostic techs have become much more reliant upon the scan tool as a primary method of diagnosing malfunction indicator light (MIL) issues. In addition

Monitoring Emission Efficiency With O2 Sensors

As modern OBD II technology marches on, it’s clear that the zirconia-based oxygen sensor now is being sold more as a basic repair part than as a preventive maintenance part, and it changes the way we diagnose and sell oxygen sensors. To illustrate the difference, let’s remember that an oxygen sensor replacement used to be

Getting to the Heart of Electrical Systems

In current SAE J1930 terminology, the “alternator” is now being referred to as a “generator.” Of course, this isn’t news for many technicians because many vehicles have always been equipped with “generators” for several years. By either name, the alternator’s job has definitely become more complex during the past decade. Years ago, the typical vehicle

Rotors and Pads: Analyzing Replacement Options

Although the industry has seen anti-lock braking systems (ABS) become standard equipment on modern imports, the majority of brake service still focuses on the replacement of brake pads and rotors. Rotor replacement, of course, has changed because new rotors have become a more cost-effective method of resolving pedal pulsation and brake shimmy problems associated with

Sales Opps in Head Gasket Replacement

During some point in their service lives, most older gasoline engines built with cast-iron cylinder blocks and aluminum cylinder heads will need a cylinder head gasket replacement. The vulnerability of aluminum-head engines to head gasket failure is caused by the aluminum cylinder head expanding approximately 1.5 times more than the cast-iron block. Although measured in

Diagnostic Solutions: Charging System Service

Drive belts are an often-overlooked component during routine maintenance service intervals Drive belts last so long on late-model imports that it’s very easy to forget about inspecting them during a scheduled maintenance interval. In the early days of import cars, drive belts didn’t last as long because many were made from a leather belt joined

Diagnostic Dilemmas: The Effects of Warm-Up Laps on a Running Engine

Most diagnostic technicians have experienced the frustrations of troubleshooting temperature-related engine performance problems. All too often, the true nature of the problem is concealed by the very fact that it occurs only at specific engine temperatures. If the engine quickly passes through the critical temperature range needed to duplicate the problem, the problem can easily

Friction Material Selection

Because today’s lighter and more friction-efficient disc brakes have become very sensitive to differences in friction materials, the issue of selecting a quality brake pad is becoming increasingly relevant to the quality-conscious installer. To illustrate, aftermarket manufacturers of high-performance disc brakes offer literally dozens of racing pads that are qualitatively equal, but vary widely in

Ball Joints & Bushings: Worn Components Take Their Toll on Advanced Suspension Technologies

Too often, shop owners and technicians alike assume that suspension systems haven’t changed much in the past 20 years. In reality, nothing could be farther from the truth because today’s import vehicle may incorporate a number of technologies that can be affected by worn steering and suspension components. To illustrate, we’re beginning to see electronic

Selling Service for Low-Maintenance Ignition Systems

ition system maintenance as long as it feels like it’s “running good.” In reality, spark plugs eventually develop high electrical resistance because the electrodes wear away. When this happens, the secondary ignition voltage will increase until the ignition coil, ignition cable, spark plug boot or spark plug develops a high-voltage leak. When a high-voltage leak