What Does Brake Retarder Prohibited Mean?

Brake retarders help increase brake efficiency of heavier vehicles. But then why are they prohibited in some areas? What does brake retarder prohibited mean and will I be fined for using them on my trailer or truck? Let us find out.

Imagine you are driving a heavy vehicle like a truck or bus and moving downhill. You need to apply the brakes several times to slow down or control your vehicle. 

Your vehicle’s braking system consists of friction lining that can get overheated while moving downhill. Overheating may cause lead to brake fade or brake failure, which is dangerous for your life while driving on the road.

That is why trucks and heavier (class-A) motorhomes are equipped with retarders. They use the pressure created within the four-stroke engine and help slow down or control the vehicle’s speed while traveling downhill.

Moreover, they do not adversely affect the conventional braking system. But retarders can cause your vehicle wheels to skid if it has poor traction with the road surface. So it is better to turn off your retarder when traveling on a wet or snowy road.

But you might have noticed the sign “brake retarders prohibited” in many cities. What does that mean, and why would someone want to stop vehicles with retarders? The article discusses Jake’s brakes in detail. So, keep on reading the article for more information.


What Does Brake Retarder Prohibited Mean


What Is A Brake Retarder?

A brake retarder is a mechanical device that helps to slow down your vehicle and helps it to maintain a steady speed without any effect on the conventional braking system. 

Brake retarders are also called Jake’s brakes, a shorter version of the term “Jacob’s engine brake retarders”. The name comes from Jacobs vehicle systems, a company founded by Clessie Lyle Cummins, who was also the founder of Cummins inc.

There are mainly four types of brake retarders. They are as follows.

  • Hydraulic
  • Exhaust
  • Engine
  • Electric


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#1. Hydraulic Retarders

Hydraulic retarders use fluid mechanics to help slow down your heavy vehicle. This is somewhat similar to how normal disc brakes operate.

Compressed air is blown into the oil container in a hydraulic retarder. After some time, the level of the oil drops, and the oil moves towards the retarder circuit. 

The retarder circuit consists of helical gears, springs, stators, and rotors. When the oil comes in contact with the rotor, it starts reducing its speed, and finally, a point comes when it gets attached to the stator with the help of helical gear. 

This causes your vehicle to slow down. The rotor is connected to the propeller shaft, which is connected to the main shaft of the gearbox. The oil gets heated when there is the application of retarder. So it needs to be cooled. 

That’s why the heated oil from the retarder circuit, is made to flow across the heat exchanger, where it exchanges heat with the air and then goes to the oil pump.

#2. Electric Retarders

The engine retarder uses the concept of electromagnetic induction to stop your vehicle. Whenever you require your vehicle to retard, the electrical windings in the stator will receive power from the battery and produce a magnetic field by which the rotor will move. The rotor will create an opposing magnetic field which helps in slowing down your vehicle.


What Does Brake Retarder Prohibited Mean


#3. Exhaust Retarders

Whenever you apply an exhaust braking system in your vehicle, then the butterfly valve closes the exhaust valve. Consequently, it will raise the pressure inside the cylinder, and it will again act as an air compressor, which helps reduce the engine’s speed.

#4. Engine Retarders

The exhaust valve opens in the compression stroke of a diesel-powered engine in the engine braking system. It excels the compressed air outside, which helps in slowing down your vehicle.


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Working Principle Of An Engine Brake System

The engine brake system is usually found in vehicles equipped with a compression ignition engine or diesel engine. So, before discussing the working principle of the engine brake system, you should know the working principle of a four-stroke diesel engine.

Diesel Engine

Usually, there are four phases in a normal four-stroke diesel engine or compression ignition engine, i.e., suction, compression, power, and exhaust.

In the suction stroke, the air is drawn inside the cylinder. The inlet and exhaust valve both are closed in this position. The piston moves from the top dead center to the bottom dead center.

The piston moves from bottom dead center to top dead center in the compression stroke. The air is compressed to high pressure and temperature, but the inlet and exhaust valves are closed in this position.

The fuel injects air in a power stroke and the mixture burns. The inlet and exhaust valves are closed here. The piston moves from the top dead center to the bottom dead center.

The piston moves from bottom dead center to top dead center in the exhaust stroke. The exhaust valve opens, and the burning gases are expelled.


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Engine Brake System

The engine brake systems are usually found in heavy vehicles like trucks, buses, and others. It also has four phases, like a four-stroke diesel engine.

The suction stroke remains the same as a normal four-stroke diesel engine. But when the engine brake system in a diesel engine is active, there is a change in the compression stroke. The inlet valve is closed, but the exhaust valve opens in this phase. The air is expelled into the atmosphere.

In power stroke, both the inlet and exhaust valve is closed. The electronic control unit also stops supplying the fuel.

The cylinder will create a vacuum when the piston moves from the top dead center to the bottom dead center. So there will be much load on the crank, and finally, the engine will slow down.


What Does Brake Retarder Prohibited Mean


The inlet valve is closed in the exhaust stroke, and the exhaust valve is open. The piston moves from bottom dead center to top dead center, and the exhaust gas releases into the atmosphere.

There is an additional circuit in the vehicle equipped with the engine brake system. It consists of an oil pump, solenoid valve, control valve, and actuator.

When the engine brake system is on, the oil pumps oil to the solenoid valve. The Electronic control unit controls the solenoid valve.

Then the oil moves to the control valve, where its pressure is controlled. Then it moves to the actuator. The pressurized oil in the actuator helps push the exhaust valve and open it in the compression stroke. Once the engine brake turns off, the oil in the actuator goes to the sump. The oil cannot be pumped further.


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What Are The Advantages Of Using Jake Brake?

Despite loud noise, Jake’s brakes have immense benefits. Let’s discuss them below.

#1. Saves Maintenance Cost Of Your Vehicle

The vehicles equipped with Jake brakes can help in saving you money. If you use a conventional braking system repeatedly in heavy traffic areas or while going downhill, it can significantly damage your brakes. 

Repairing or replacing the brake components is quite expensive. As braking systems are vital for your safety, you have to spend a lot of money on fixing them.

But if your vehicle has Jake brakes, it will help slow down your vehicle in traffic areas and downhills without adversely affecting the conventional braking system like disc brakes, drum brakes, parking brakes, etc.


What Does Brake Retarder Prohibited Mean


#2. Reduces Pressure On Conventional Brakes

If you always use our conventional braking system, then it will put extra pressure on the braking components like the brake pad, caliper and others. 

That’s why these components will wear and tear very quickly. Moreover, it can also cause the brakes to overheat, which is quite dangerous while driving on roads.

But using Jake brakes will helps in reducing pressure on your brake system. It helps increase the life span of your vehicle’s braking system.

#3. Lessen Stopping time Of Your Vehicle

If you are driving a heavy-weight vehicle like a bus or truck in traffic areas, and if it does not stop at the wrong time, it can collide with other dangerous objects. 

But if your vehicle has a jake braking system, it will ensure your vehicle stops in the correct time and lessen the risk of colliding with any other vehicle.


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What Does Brake Retarder Prohibited mean? 

The compression release engine brake or jake brake is a retarder found in diesel-powered engines. They no doubt help control the speed of your vehicle while traveling down the hill, but they have certain disadvantages. 

These brake retarders (commonly known as “Jake’s brakes” produce a lot of noise, which people are not happy with especially in quiet suburban areas. 

This is why you will often find that brake retarders are prohibited from entering in residential areas or near toll roads. Sometimes truck drivers are even fined for using Jake’s brakes in prohibited places.

Why Is Engine Braking System Or Jake Brake System So Loud?

You usually hear loud irritating sounds coming from the silencer once the engine brake is activated. But do you know why you hear such a sound? 

In the compression stroke, the air is compressed to very high pressure. Suddenly the exhaust valve is opened, and the air expels outside, and thus you hear a very loud sound that can irritate or disturb anyone. So drivers are not allowed to use the jake brake in the residential areas.

If an engine braking system or jake braking is not allowed in your locality, you will see one of the below signs posted.

  • No Jake brakes
  • Jake braking prohibited
  • Compression braking prohibited
  • Engine braking prohibited
  • Brake retarders prohibited


What Does Brake Retarder Prohibited Mean


If a bus or truck driver uses the engine brake in places prohibited, he will have to give a fine.

Fortunately, there are many places like mountainous regions where Jake brakes are not prohibited because there are not many residential places there.

However, today most companies are developing new technology to lessen the noise produced by the engine braking system. For instance, some companies are making mufflers to reduce loud noise. 

It will help drivers of heavier vehicles go to areas where Jake’s brakes are strictly prohibited because they will no longer produce a loud noise.


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Regulation Around Jake’s Brakes

There are four states in the US that have specific statutes specifically regulating Jakes brakes, but many others have issued regulatory ordinances and other things that address vehicles that use them

It’s important to note that not all regulation is negative – while some states have specifically disallowed the use of Jakes brakes in some areas, others have outlined the benefits thereby permitting them in some parts of the state.

Let us look at it state by state.

#1. Colorado

Colorado recognizes that heavy vehicles with brake retarders may cause a lot of noise and have thereby issued a statute that requires them to use a muffler to lower the decibel level. Any violation of this rule will incur a fine of upto $500.

On the other hand, the state also recognizes the benefits of these brake retarders, specifically in the case of school buses used in mountainous areas. In such cases, the state explicitly prohibits passengers from using the front and emergency row seats unless the vehicle uses brake retarders.

Colorado encourages the use of electromagnetic retarders which produce relatively lower noise.

#2. California

The state of California recognizes that brake retarders are necessary for heavy vehicles. It requires all fire trucks that weigh over 31,000 pounds (GVW) to use brake retarders.


What Does Brake Retarder Prohibited Mean


#3. Montana 

Montana addresses the noise problem by requiring any vehicle that uses Jake’s brakes to put up mufflers. As long as you have a working muffler, you cannot be prohibited from using engine compression braking. 

However, the state also recognizes the noise problem and does not allow indiscriminate use of the retarders in truck tractors, trailers, trucks, and their variant vehicles.

#4. Kansas

Kansas has taken a stricter route to Montana by banning engine retarders on trucks, trailer, and their variants.

#5. Pennsylvania

Pennsylvania has a more nuanced regulation with regards to Jake’s brakes. 

All highway vehicles with a gross weight of more than 80,000 pounds must have an engine, hydraulic, or exhaust retarder. Local authorities are banned from prohibiting their use without a prior approval from DoT.

#6. Oklahoma 

Oklahoma does not allow special combination vehicles such as truck and trailer combinations to use retarders indiscriminately.

#7. Oregon 

If you are traveling on a highway in Oregon, you need to have mufflers installed on your Jake brakes. If not, you can be fined upto $720.


Many other states explicitly allow the use of brake retarders specifically on school buses. This includes Wyoming, West Virginia, Utah, Oregon, New Mexico, Delaware and Arkansas.


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Frequently Asked Questions

#1. Why are engine retarder brakes prohibited?

Whenever you use engine retarder brakes in diesel-powered vehicles, it produces loud noise, disturbing people in residential areas. That is why engine brakes are not permitted in various places.

#2. What do retarders mean in trucking?

The engine braking system is mainly used as a retarder in trucks and other heavy vehicles. The engine brake or jake brakes open the exhaust valve in the compression stroke, which allows the compressed air to go outside. It dramatically reduces the speed of the engine.

#3. What is the difference between an engine brake and a retarder?

When the engine brakes are activated, it produces loud noise that can irritate anyone. That’s why they are banned in many states of the United States.

But the exhaust braking system(a type of retarder) is very quiet and will not produce any sound which can disturb anyone.


What Does Brake Retarder Prohibited Mean


#4. Are Jake Brakes Illegal In Colorado?

The heavy vehicles equipped with an engine braking system or jake brakes should have proper mufflers to reduce the sound. If the vehicle does not have a muffler, then the cops can impose a fine of $500.

#5. Can You Use Jake Brakes In California?

No, you cannot use jake brakes in California. You will find a sign posted as No jake brakes or Jakes brakes prohibited in most places. If you drive a vehicle in such places and use an engine braking system or jake brakes, you have to give a hefty fine.

#6. In Which States Are Jake Brakes Illegal?

The National Highway Traffic Safety Administration says that many municipalities have banned jake brakes because of loud noise


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A Few Final Words

You will find jake brakes in most heavy vehicles like school buses, trailers, fire engines etc. They are used to control the truck’s speed while descending on a hill rather than using a conventional braking system. 

Thus indirectly, they increase the life of the expensive braking components of your vehicle. But don’t use jake brakes on slippery roads because of snow, ice, or rain.

Moreover, they are prohibited to use in some areas of the United States because of loud noise. So, if you see a sign posted as No Jake Brakes, then better not use their engine braking system; otherwise, you will have to pay a hefty amount as a fine.

Thank you for reading the article, we hope this clarifies all your questions regarding brake retarders. If you have any further doubts, do write to us in the comments section and we will get back to you with answers.

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Sean Mendez

Hi, I am Sean, a self-confessed petrolhead. I live in Boise, Idaho with a busy family of four and our energetic Labrador retriever. Thank you for visiting my website. You can find my email on the contact page.

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