The ASE G1 Certification test contains 55 scored questions, plus 10 unscored ­research questions, that cover a range of skills and knowledge related to maintenance and light repairs in engine systems, automatic transmission/transaxle, manual drivetrain and axles, suspension and steering, brakes, electrical, and heating and air conditioning. Related Articles - Do Airless Tires Mean TPMS is a Thing of the Past? - Front Brake Pads and Rotors: Do Your Prices Meet Market Averages? - Tips for Turning Off the TPMS Light

As part of the engine systems portion, you must know how to inspect, replace and adjust drive belt(s), tensioner(s), and pulleys.

Mileage is a big factor in belt wear, but so is general age, regardless of use. Modern belts, made of the durable synthetic rubber known as ethylene propylene diene monomer (EPDM), last much longer than older neoprene belts, but they do still get old, wear down and lose performance.

Neoprene belts should be replaced if there are three cracks in a three-inch section, but EPDM belts resist cracking because of their increased elasticity. This is why a visual check for cracks isn’t the best indicator of true belt wear. EPDM belts can run 100,000 miles or beyond with no visual cracks. A far better indicator of wear on EPDM belts is material loss. Serpentine belt drives are exposed to grit, rocks, salt and water, and, over time, these contaminants along with slight misalignments result in wear of the rubber rib surface.

A belt is like a tire in that over time its tread will wear down, which will reduce its performance. As a belt’s ribs start to wear and flatten, a belt starts to lose its ability to grip or function properly, causing it to slip, which puts a strain on other components within the engine. As little as 5% rib material loss and surface wear can affect how the belt performs, and just 10% belt slippage can affect the overall driveability of a vehicle.

In terms of vehicle performance, a persistent check engine light, reduced engine cooling, inconsistent power steering performance or poor A/C system performance are all signs of belt slip caused by wear.

Another problem associated with material loss is how the belt fits around the pulley. Belts are designed to allow clearance between itself and the pulley. Losing this material widens the space between ribs and erodes this clearance. Without that clearance, water and debris lose a path through the system, and can result in hydroplaning.

Belt noise or premature wear on the belts in some vehicles is often the result of a bad automatic tensioner. When a serpentine belt is noisy, slipping or fluttering, be sure to check the tensioner.

But these days, there might not be a tensioner. Today’s stretch belts have special polyamide tension cords inside that allow them to stretch to maintain tension without the need for a tensioner. An ordinary serpentine belt and a stretch belt are not interchangeable. Attempting to stretch an ordinary serpentine belt over a pulley can damage the cords inside it and cause the belt to fail. Installation of a stretch belt requires a special tool to extend it over the final pulley.

To further reduce stress on drive belts and other accessory components, OEs started to incorporate overrunning alternator pulleys (OAP) and decouplers (OAD), moving away from the standard one-piece alternator pulley. OAPs and OADs allow belts to “overrun” and, therefore, they absorb the damaging vibrations of drive system operation instead of the belts and attached components.

When OAPs or OADs are compromised, they can no longer absorb the same level of abuse, which has a trickle down effect throughout the system. Belts and tensioners are then much more likely to overstress and fail.

OAPs and OADs should be inspected every 10,000 miles for wear. Early design versions have provided service life of 40,000 to 60,000 miles, with more recent versions lasting more than 100,000 miles. Also, note that OAPs and OADs are not interchangeable and must be replaced with the same type of pulley or decoupler.

When looking for OAP and OAD failure, be sure to look at the bearings, clutch assembly and the internal spring of the decoupler:

In any of the above scenarios, the OAP or OAD needs to be replaced.

Never force or pry a belt over pulley flanges. If the belt cannot be run into the grooves by rotating the pulley, move the belt-driven accessory to obtain closer centers. With the belt removed, examine the pulleys for damage and misalignment. Replace pulleys as required and install the new belt.

A new drive belt should also be installed when a high-mileage water pump is replaced. Chances are the old belt will have a lot of miles on it and will be badly worn, glazed or contaminated with oil, grease or PS fluid that leaked out of the old pump. The automatic belt tensioner also should be carefully inspected and replaced if it is sticking, rusty, wobbling, noisy or can’t maintain proper belt tension. n

The R1234yf refrigerant that will be required in all new cars next year has actually been found in vehicles since 2014 when Chrysler began using it in the Dodge Demon and Jeep Trackhawk, among others. Unfortunately, it’s difficult to tell with certainty how many vehicles already have R1234yf due to the phasing in the process

The R1234yf refrigerant that will be required in all new cars next year has actually been found in vehicles since 2014 when Chrysler began using it in the Dodge Demon and Jeep Trackhawk, among others.

Unfortunately, it’s difficult to tell with certainty how many vehicles already have R1234yf due to the phasing in the process over the past 10 years – some estimate it is already well over 50 million vehicles. It is not a question of if, but when you’ll have to deal with this refrigerant. While working on R1234yf systems is not that different from the R134a variety in operation or theory, identifying the refrigerant and recharging the system has some new twists.

Don’t you wish everything aged like a fine wine? While that dry red gets better as the years go on, we humans are subject to old age and wrinkles and our great inventions like cars get rusted and worn out. Tires on those cars get worn out, too. Like our bodies, the more miles you

TPMS, like most technologies, is always evolving, and that is a good thing. The more accurate the system becomes and the more features that are added to a TPMS system, the more likely the driver will find value in keeping their TPMS system functioning. In the past 10 years alone: Related Articles – Don’t Let

You probably haven’t seen tapered wheel bearings in many late-model vehicles. It seems that nearly every vehicle made these days will run some sort of wheel hub assembly. There are a number of reasons for this, but the biggest reason is this: ease of assembly. Not assembly for those of us that work on these

No road is entirely flat. Even a small tar strip or dip causes movement in the suspension. This movement is controlled by the spring and dampener. No matter the type of movement, the spring is compressed and then releases the energy into the body, dampener or road. Related Articles – Catalytic Converter Theft: How it

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One of the first items to be replaced on any Tesla model are the tires. This is due to tire wear from the instant torque of the electric motor. When replacing the tires, you will have to service the TPMS sensors. Related Articles – ZC Rubber Introduces EV PRO Tire Lineup in China – Michelin

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