What Do Regenerative Brakes Look Like?

Regenerative brakes use the rotation of the wheels applied to the electric traction (drive) motor to create electricity. Therefore, the brakes themselves look the same as conventional brakes because the hydraulic brakes are still in place and work the same as conventional brakes. The major difference is that the standard wheel brakes work mostly at low vehicle speeds, whereas conventional brakes work at all speeds. As a result, the brakes on a hybrid electric vehicle should last many times longer than the brakes on a conventional vehicle.

The letters "EF" on the edge of a brake lining mean ______________.

a. Wear resistance codes

b. Relative noise level codes

c. Coefficient of friction codes

d. Brake lining composition



Answer/Explanation

The correct answer is c. The edge code letters represent the coefficient of friction codes; the first letter indicates when the lining is cold and the second when the lining is hot. Answer a is not correct because the edge codes do not indicate wear factors. Answer b is not correct because edge codes do not indicate noise factors. Answer d is not correct because even though parts of the code identify the manufacturer, they do not indicate the composition of the lining material.

"B" Means Braking

All Toyota hybrid vehicles have a position on the gear selector marked “B.” This position is to be used when descending steep grades and the regenerative braking is optimized. This position allows the safe and controlled descent without having the driver use the base brakes. Having to use the base brakes only wastes energy that could be captured and returned to the batteries. It can also cause the brakes to overheat.

Three Brake Jobs in 40,000 Miles

A service technician was asked to replace the front disc brake pads on a Buick because the sensors were touching the rotors and making a squealing sound. This was the third time that the

front brakes needed to be replaced. Previous brake repairs had been limited to replacement of the front disc brake pads only. When the caliper was removed and the pads inspected, it was discovered that a part of one pad had broken and a piece of the lining was missing Then the technician spotted something at the rear of the vehicle that told the whole story—a trailer hitch. The owner confirmed that a heavy jet ski was towed in hilly terrain. The technician recommended overhauling the front disc brake calipers to prevent the possibility of the front pads dragging. The technician also recommended an inspection of the rear brakes. The rear brakes were glazed and out of adjustment. The technician received permission to replace the rear brakes, replace both front calipers, and install quality disc brake pads. When the customer returned, the technician advised the customer to use a lower gear in the transmission on long downhill roads to help keep the brakes from overheating and failing prematurely.



Summary

·     Concern—The front calipers needed replacement more often than expected.

·     Cause—The front calipers were not retracting and the rear brakes were not working as designed.

·     Correction—Front calipers were replaced and the rear brakes were serviced. Plus, the owner was advised to use the gear selector when descending long grades to reduce the load on the brakes.

From the July Wheels section of the Dayton Daily News.

Wheels:

Bruce from Florida asks:

“I own an old (1987) Ford Mustang convertible that I love and it needs tires. I would also like to replace the wheels but I want to keep raised white letter tires that are only available for 14 inch and 15-inch wheels. I have 14-inch wheels now that are original. The tire and wheel shops around me want to sell me larger diameter wheels but then I would not have raised white letter tires. Any help would be appreciated.”



Halderman:

Owners of vehicles are often confused when it comes to replacing tires. The things that need to be checked when replacing tires include:

1. The correct size. A tire size describes the width of the tire, the height of the sidewall, and the rim diameter. This should be the same size that was originally on the vehicle.

2. Speed rating. The speed rating is given as a letter (Q, T, S, H, V, W, and Y) and should be

the same as the original tires that came with the vehicle.

3. If the vehicle will be driven in a climate that is above 45°F (7°C), summer-type tires can be used. If the vehicle will be driven under a variety of conditions and both above and below 45°F (7°C), all-season type tires should be selected.

If changing to a larger wheel, such as to 15-inch wheels so that you can get the raised white letter tires, it is important that the same outside diameter of the tire/wheel assembly be kept the same. This is important because it can affect the speedometer and the shifting of the automatic transmission as well as headlight aiming. Most tire and wheel stores will select the proper size wheel/tire combination that will work and keep the same diameter as the original wheel/tire combination.

Most wheels are designed to fit over and be supported by the axle hub. Some wheels use an enlarged center hub section and rely on the wheel studs for support and to keep the wheel centered on the axle. Some aftermarket wheels may be designed to fit several different vehicles. As a result, the wheel manufacturers use plastic hub-centric adapter rings to adapt the wheel to the vehicle.

A useful website I have used to help narrow down the proper size needed is:

https://www.willtheyfit.com/

Have an automotive question? Get a straight answer by writing to Jim at jim@jameshalderman.com

Answer To This Month's Trivia:

C. Cooling