master cylinder

A Brief History of Automotive Brakes

When I think about the most essential car components, I always think of the brakes. Over the years, cars have been equipped with lots of different braking systems. In this article, we’re going to take a look at the history of brakes and how they came to be. Stick around if you’re in the mood to learn something new.

Wooden block brakes

The first form of automotive brakes were wooden block brakes. As the name implies, the system was made up of wooden blocks and a lever. The lever pushed the wooden block against the steel-rimmed wheels. This produced friction, which ground the vehicle to a halt.

Wooden block brakes were originally used in horse-drawn carriages and steam cars. They worked as long as the vehicle was traveling at most 10 to 20 miles per hour. By the 1890s, wooden block brakes fell out of use. This is when rubber tires were introduced. ​Since wooden block brakes only worked with steel-rimmed wheels, they became obsolete.

Mechanical drum brakes

An engineer named Gottlieb Daimler conceptualized a new braking system in 1899. He thought that if he attached a drum wrapped in cable to the car’s base frame, it could stop a moving vehicle. In 1902, Louis Renault furthered this idea when he built the first mechanical drum brake. Renault’s brakes are considered the foundation for modern automotive brakes.

Expanding internal shoe brakes

Renault’s braking system was an improvement, but it still malfunctioned quite often. This was due to the system being external. This exposed the brakes to extreme temperatures, dust, and rainfall. As a result, an internal braking system was developed. This new system was stored inside of a metal drum, which was connected to the wheel. Inside the drum, brake shoes were expanded by pistons, which caused the brake shoes to graze against the inside of the drum. This friction made the wheels slow down, eventually stopping the vehicle.

Hydraulic brakes

The issue with expanding internal shoe brakes was that they required a significant amount of force to stop the vehicle. Malcolm Loughead solved this problem by inventing the first four-wheel hydraulic braking system. Hydraulic brakes use brake fluid to transport force from

the brake pedal to the brake shoe. This system required a lot less force to stop a moving car. Hydraulics became popular and were incorporated in many vehicles by the late 1920s.

Disc brakes

Eventually, as car sizes and speed capacities increased, hydraulic brakes became less effective. Automakers needed a new system. They began using disc brakes that had hydraulic functions. Disc brakes have been around since 1902, when they were invented by William Lanchester. They didn’t become widespread until the mid-20th century, when they were used in conjunction with hydraulics.

Anti-lock brakes

Anti-lock brakes have been around since the 1920s and ‘30s, but they were originally used in airplanes. By the 1950s and ‘60s, they automakers started offering them as a safety feature. Anti-lock brakes are a significant innovation because they give the driver more control. They stop brakes from locking up while in use. The hydraulic valves take brake pressure off one wheel, which prevents the car from spinning out of control. By the 1970s, anti-lock brakes were a popular auto feature.

Does your car need brake maintenance? Our experienced technicians at Carlson Automotive can help. You can ​request an appointment online​, or by phone. Give us a call at (651) 458-5158 for our Cottage Grove Location, or (651) 578-0885 for our Maplewood location. We look forward to seeing you soon.


What’s a master cylinder?

The master cylinder is an essential part of your brake system, but it often goes unrecognized. Today we’re talking all about master cylinders, and how they’ve evolved over time. Buckle up and enjoy the ride. The master cylinder uses hydraulic force to move power from your brake pedal to your wheels. When you hit the brakes, the force from your foot travels through this cylinder to your brake calipers. The calipers then clamp down onto your rotors. This stops the rotation of your wheels, bringing your car to a stop.

A lot of gearheads will tell you that the master cylinder is the heart of your car. This is because it pumps brake fluid to the brake lines, similar to how your heart pumps blood to your arteries. Both the master cylinder and the heart facilitate movement of fluid to where it’s needed.

How does the master cylinder work?

Let’s dive into some of the specifics. When you hit your brake pedal, it pushes a rod called, simply enough, a pushrod. The pushrod enters the dual-chamber master cylinder. Inside this cylinder, there’s a spring and two pistons. These pistons operate like plungers to push brake fluid through the master cylinder’s chambers. When these pistons move forward, it causes a build-up of hydraulic pressure. This pressure makes the calipers clamp down on the rotors, stopping your wheels.

In order for your hydraulic system to operate, it needs to be airtight. To ensure no air enters the system, there’s a reservoir above the master cylinder. When you take your foot off the brake pedal, fluid travels back through the brake lines and into the reservoir.

Evolution of the master cylinder in cars

In 1918, a man named Malcolm Lougheed invented hydraulic brakes. He was the first person to send liquid pressure against brake shoes to push them against the drums. Chrysler took Lougheed’s hydraulic model and made some improvements. They re-branded these as Chrysler-Lockheed hydraulic brakes. They were in use from 1924 until 1962.

Although Lougheed’s system was an improvement from earlier brakes, it had a big problem. Because it only had one cylinder, a single leak or fault in the system meant that all of your brakes would stop working. Not only was this inconvenient, it was extremely dangerous.

Wagner Electric improved on this model in 1960 with their invention of a dual-cylinder brake system. Similarly, in 1962, Cadillac developed a brake system that separated rear and front hydraulic lines. American Motors also created a dual-cylinder system that separated the hydraulic lines diagonally. That way, you would have one front and one rear wheel with functioning brakes, even if one circuit malfunctioned. In 1967, the federal government mandated that all cars be built with dual-braking master cylinders. It’s reported that this prevents about 40,000 car accidents each year.

The next time you hit the brakes, think about what’s going on inside your car to get the wheels to stop. There are a lot of moving parts, and the master cylinder is the heart of it all. Does your master cylinder need some extra care? Our experienced technicians at Carlson Automotive are here to help. You can ​request an appointment online​, or by phone. You can reach us at (651) 458-5158 for our Cottage Grove Location, or (651) 578-0885 for our Maplewood location.


7 Warning Signs Your Car Needs Brake Repair

Putting off car maintenance is never a good idea, especially when it comes to your brakes. Fortunately, our cars are pretty good at letting us know when there’s an issue. Below are 7 common signs your brakes need maintenance.

1. Grinding sound from the brake pedal

If you hear something that sounds like grinding, it could point to a few different problems. There might be a loose pebble stuck in the caliper, which is a minor fix. Grinding could also mean that there’s rust in your braking system. It could also be the brake pad wear indicator scraping the rotor.

2. Wobbling or vibration

Do you notice a wobbling or vibrating sensation while driving? This could mean you have an uneven rotor. As time passes, all rotors develop slight variations on their surfaces. The differences in thickness can cause wobbling when you hit the brake pedal. Vibrations or wobbling may also point to a caliper problem. If its piston has rust or excess debris around it, then the caliper won’t retract all the way when you release your foot from the pedal.

3. Squealing noise when braking

If your car makes a horrendous, squealing noise, you’ll know you have a brake issue. This unmistakable sound is from the brake pad wear indicators. These let you know when the calipers or brake shoes are worn out. Since they’re made of metal, they make a high-pitched screech when they brush up against the rotor.

4. Pulling to one side while braking

Another sign of an unhealthy brake system is your vehicle pulling to one side while braking. This usually means you have an issue with your two front brakes. It could be a misaligned rotor, a worn out brake hose, or a caliper issue. Any of these issues will result in your car braking unevenly. This is because the fully functioning side tries to compensate for the damaged side.

5. Burning smell while driving

Smelling something burning while you’re driving is never a good sign. A burning, chemical odor could mean you have overheated brakes. If you suspect this, stop driving right away and give your brakes enough time to cool down. Overheated brakes mean your brake fluid has reached a boiling point, and your entire braking system could fail.

6. Brake light illuminated on the dashboard

An illuminated brake light is the most obvious sign of an issue with your brakes. Located on your dashboard, the brake light is activated by your car’s diagnostics system for several reasons. To understand exactly what’s going on, you’ll need to take your car in for an inspection.

7. Soft or spongy brake feel or leaking fluid

Excess moisture in your braking system will result in your brake pedal feeling oddly soft or spongy. It usually points to a leak in your hydraulic system. Your brakes use pressurized, hydraulic brake fluid. Without enough hydraulic force, your brake pads won’t be able to clamp down onto the rotors. If the brake fluid leaks, your brakes could stop working altogether.

To understand exactly what’s going on, it’s best to have your brakes checked out by a professional. Our experienced technicians at Carlson Automotive can help. You can ​request an appointment online or by phone. Give us a call at (651) 458-5158 for our Cottage Grove Location, or (651) 578-0885 for our Maplewood location.


What You Need to Know About Replacing Your Brakes

Replacing the brakes on your car isn’t an easy task. Unlike other car maintenance, brake work has the potential to uncover underlying problems. These issues will need troubleshooting because the brake system is interconnected and complex. Today we’re discussing some general steps for replacing your brake system. Knowing about the process can help you decide if this is a job you can take on, or if you need help from an experienced professional.

Steps to replacing the brake system

When replacing the brakes, there’s always potential for complications. Even so, auto mechanics will generally follow these steps:

  1. Loosen the lugs​: With the emergency brake engaged, use a lug wrench to loosen the lugs. Make sure not to unfasten them completely.
  2. Raise the vehicle​: Position the car jack beneath your vehicle’s frame rail. Ensure that the jack stands are underneath your car. Rest your vehicle on the jack stands, and be certain that it’s stable. Once you know the car’s weight can’t shift, take off the wheels.
  3. Slide out the caliper​: Disconnect the bolts and slide out the caliper. If it gets stuck, you can pry it out using a flat head screwdriver. Be sure there’s no strain placed on the brake line of the caliper.
  4. Remove the caliper carrier​: Disconnect the two bolts that secure the caliper carrier in place. Then, detach the caliper carrier.
  5. Remove the rotor: Before removing the rotor, look to see if yours has a locating screw. If it does, remove this screw first. Removing the rotor can be challenging if there’s an accumulation of rust or debris.
  6. Install new rotor​: Clean any rust from the surface of the hub using a wire brush. Then, install the new rotor. Remove excess oil from the new rotor with a degreaser or brake cleaner.
  7. Assemble caliper carrier​: Reattach the caliper carrier and fasten on new bolts.
  8. Compress the caliper​: Use a c-clamp and an old brake pad to align the caliper’s piston with the caliper housing. When doing this,make sure the cap is removed from the brake reservoir, or you could risk blowing a line.
  9. Install caliper and brake pads​: Insert the brake pads in the caliper carrier. Fasten the caliper bolts to hold it in place. Verify that the caliper can move without binding or seizing up. Then, secure the bolts.
  10. Re-attach the wheels​: Manually connect the lugs. When your wheels are on the ground, use a torque wrench on them.
  11. Repeat, pump, and break in: Repeat these steps for all 4 of your wheels. Then, step on the brakes until pressure is reached. This usually takes about 3 pedal pumps. Your last step is to break in your new system. Go through a few cycles of accelerating and allowing your car to gradually slow back down. You might hear odd noises at first, but these should eventually subside.

Should I replace my own brakes?

Brakes are complicated. Unless you really know what you’re doing, brake replacement is best left to the professionals. By trusting an expert, you’ll be able to rest easy knowing your brakes are getting proper care.

Do your brakes need to be replaced? Let our experienced technicians at Carlson Automotive lend you a hand. Give us a call at (651) 458-5158 for our Cottage Grove Location, or (651) 578-0885 for our Maplewood location. You can also ​request an appointment online​. We look forward to serving you.