Author Archives: Calvin

Before ABS: Anti-Skid Brake Systems

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imp1971surebrakediagramDuring World War II, multiple aircraft companies developed an anti-lock brake system for  aircraft. These were a mechanical systems designed to prevent wheel skids when planes landed at high speed on slick runways. These systems sensed spikes in brake hydraulic pressure and equalized pressures.

In 1958, the first practical automotive ABS system, called Maxaret, was developed by the Road Research Laboratories in Great Britain and was installed on Jensen FF sports sedans in 1966, the Ferguson P99 race car, and an experimental all-wheel drive Ford Zodiac.

In 1969, the Lincoln Continental Mark III and the Ford Thunderbird were equipped with an Auto-Linear anti-lock unit developed by Kelsey-Hayes. Sensors on the rear wheels transmitted signals to an electronic module behind the glove box. The system controlled a vacuum- operated valve on the rear brake line to modulate pressure when anti-lock brake assist was needed.

GM developed a similar system for its Oldsmobile Tornado and Cadillac Eldorado models for 1970 as an option. These front-wheel-drive behemoths had most of the weight of the transmission and huge V8 over the front wheels. The biggest issue with these vehicles was the self-check after the vehicle started rolling that made a clunk and change in pedal height that the customer would notice.

These systems fell off the options lists in the early 1980s. Now, they are standard equipment mandated by the government as of 2009.

Should you jump/bail from the car if your brakes fail? NO

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If your brakes fail, you should stay with the vehicle. When your are inside the vehicle you still have more control and safety devices then if your were “rag dolling” down the freeway. Today a driver decided to bail when her brakes failed and caused a five car accident and four people were injured.

Curbison crash

Jasmine Curbison was traveling westbound on I-264 in Virginia during the morning rush hour. When she hit the brake pedal, the vehicle did not slow down. Instead of trying to operate the emergency brakes or pump the pedal, She decided to jump and bail from her 2002 Jeep Cherokee onto a four lane freeway.

A Honda Odyssey Minivan attempted to avoid hitting Curbison’s body, hit the rear end of the driverless Jeep. The Jeep was pushed into another car, causing that driver to hit the divider. The driver of the Honda then was struck from behind by a Saturn and that saturn was hit by another vehicle.

Once the driver of the Honda Mini-Van struck the Jeep, the Honda was then struck from behind by a 2001 Saturn, in which the Saturn was then struck by a 2013 Hyundai. Four people suffered non-life threatening injuries and the freeway had to be closed for a short period.

If Curbison decided to stay with the vehicle, even if the brakes had completely failed, the results might have been less tragic. Maybe if she had her brakes inspected and serviced, this never would have happened in the first place.

Read the Full Story At WTKR

330px-Jersey_barrier_2PRO TIP: The K-Rail/Jersey Barrier is your Friend!

A Jersey barrier or Jersey wall is a modular concrete or plastic barrier employed to separate lanes of traffic. It is designed to minimize vehicle damage in cases of incidental contact while still preventing the crossover case of a head-on collision.

When a vehicle hit the barrier, body damage is minimized by allowing the vehicle tires to ride up on the lower sloped face. This also helps to slow the vehicle. Head-ons are minimized by gradually lifting the vehicle and pivoting it away from oncoming vehicles and back into traffic heading in its original direction. A lot of test was done by the California Highway Department to get the slopes the right angles for maximum effectiveness.

If your brakes do fail on the freeway, brushing against the Jersey barrier and letting your tire ride up it is a excellent way to shed speed.

 

VIDEO: Funny Engrish Brake Lathe Video

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This video is for a cheap on the car brake lathe from China. The voice over and translation is so bad it is comical. Turn on the captions for maximum Engrish.

Here is a sample of the great translation:

“make sure that the judge should drop in your head at the same level”

“to check into wheelchair would get this does be fixing puters it doesn’t check”

“fixed abode two dicks at about 50 I’d beat work”

 

 

RANT: Commercials For DIY Brake Jobs From Parts Stores

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You are watching the game and a commercial for a national auto parts chain comes on the screen. If it is a live game, you can’t skip it. In just 20-30 seconds they try to make comparisons between wrestling or skinning a bear to replacing the brake pads on a car. I am all about empowering males to get out into the garage and doing something. But, do something besides brakes, please, have them replace an air filter or change a headlight. JUST STAY THE HECK AWAY FROM THE BRAKES.

Or, maybe buy the other 30 seconds to run disclaimer like drug commercials:

“If you have a brake job last more than four hours, please consult a mechanic. Performing your own brake job may result in longer than normal stops, rear end collisions, noise, bad smells, stains on the garage floor, loss of fingers, skid marks on your seats and possibly a fatal accident. Please see you local tool store for the correct torque tools and thread locking compounds. Failure to use these components may result in parts lose and death.”

 

RANT: Skipping Measurements on Rotors

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brake pulsationYou may think that you are not paid to measure thickness and runout, but are you paid for a comeback?

Even if you install a new rotor, you are setting yourself up for a comeback if you do not measure using a micrometer or dial indicator. Even a “perfect” premium rotor will have runout if it is put on a flange with runout or corrosion.

Installing new rotors is not a way to avoid having to use a micrometer or dial indicator. For every brake job, you should always measure for runout (rotor and flange) and the dimensions of the rotor before brake service is performed.

After the rotor is resurfaced or a new rotor is installed, the rotor should be measured for runout when it is installed on the vehicle as a quality control method. A new rotor could have excessive runout when it is installed on the vehicle due to a stacking of tolerances.

You may think that installing new rotors eliminates the possibility of a comeback. However, this myth creates more comebacks that it solves. These comebacks often start with blaming the new pads, and ends with the customer having to return a second or third time until someone pulls out a dial indicator and micrometer.

Let’s say a vehicle had .003” of lateral runout when measured at the outside face of the rotor. If this vehicle is riding on 205/55R16 tires, in one mile, the high-spot with .003” of runout goes past the caliper approximately 836 times. Over 6,000 miles, that spot on the rotor will go past the pads more than 5 million times. Every time this spot passes the pads, a little bit of the rotor’s material is removed. Over the course of those 5 million revolutions, enough material is removed to create a thickness variation that can be felt by the driver.
This is why it is critical to measure thickness and runout in a brake rotor and wheel flange even if new rotors are going to be installed.

RANT: NHTSA Video is WRONG and Dangerous

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This video from NHTSA advises NOT to pump your brakes if you experience brake line failure due to corrosion. This is WRONG. Pumping the brakes replaces lost fluid and generates more braking pressure so the vehicle can be brought under control. ABS only “pumps the brakes” when it senses that a wheel could lock or skid. If a vehicle loses brake system hydraulic fluid, the ABS system will not activate because the brakes can’t lock. Idiots.