Useful Tip: How To Manually Release Air Brakes Correctly

One of the most important skills drivers of air-braked vehicles need to know is how to manually release air brakes in case of an emergency or a malfunction.

In this blog, we will explain what brakes with air tanks are and how to manually release them in a few simple steps.

We will also provide some tips and precautions to help you avoid common problems when experiencing brake pedals or hydraulic brakes on the road.

If you want to learn more about air brakes or other skills like how to cage a brake chamber, read on!

How To Manually Release Air Brakes Correct In 4 Steps

how to manually release air brakes

If you know how to release air brakes manually, you do not find it difficult to experience the other brake in systems like frozen air brakes.

Sometimes, you can apply these steps for spring brakes or tractor spring brakes if you practice your skill smoothly. Let’s check the simple steps to use a trailer air supply valve here.

Step 1 – Get Familiar With Air Brake System

The first important thing you must do is get familiar with this system. When you touch the trailer brakes, you should learn how the trailer air brake system works.

The emergency switch is the key to releasing the brakes, and you can find it in the cab of your truck, near the dashboard.

Now that you know the trailer air brake system let’s see how to release the trailer brakes manually.

The first is to find the trailer hand control brake handle and check that its position is in the “brake off”. If you can not do that, you won’t be able to release the brakes.

You continue pressing and holding the dash valve control knob for at least five seconds. This will send air pressure to both of your service lines.

The blue line controls all four wheels, and the red line holds only two.

Step 2 – Check Parking Brakes

You need to check the parking brake control valve in this step. You must push a red button on the air tank to check the park brakes correctly.

This will help you ensure the parking brake modular controls work well.

Remember that there is a tiny difference between once-manual parking brakes and the other brakes; please check for further information from professional experts.

Step 3 – Push The Button And Check Air Pressure

Driving with caged brakes or air brakes won’t release on tractor can put you in extremely dangerous situations.

Therefore, you should find the yellow button on the yellow cap on the trailer to eliminate this problem immediately.

It is called the emergency air release valve when stuck in an incident with an electronic parking brake.

You push the yellow button to release excess air in the brake lines’ system. Keep your patience in watching your air pressure gauge and wait until it drops to zero.

That means there is no more air pressure.

Step 4 – Release Air Brakes

You must ensure that you have just charged the tractor’s air compressor and released the tractor’s parking brake.

You can get someone to help you check the trailer’s lights and confirm they all work.

It would be best if you also had an evaluation for the fifth-wheel couplings to be secure on both sides.

Then, you remove any chocks from the tractor’s wheels and clear any obstructions from your vehicle.

If you are not confident, please ask your helper to look behind the car and tell you when to pull out.

Additional Considerations And Tips

driving with caged brakes

If you are worried about risks when you apply how to release trailer brakes manually, you can note some useful tips for air brake courses below.

There are four main considerations to answer all brake questions while you experience your car. In particular:

Emergency And Normal Stops

You’re driving along, minding your own business, when suddenly, a car swerves. What do you do? You slam on the brakes, right?

That’s a smart move, as long as you have enough space to stop and you know how to brake properly.

Otherwise, you could lose control of your vehicle or cause a collision. You need to learn two simple techniques: controlled braking and stab braking.

They will help you stop your car quickly and safely while keeping it straight and ready to steer.

During normal stops, you don’t brake too hard or soft, or you could risk damaging your vehicle or endangering yourself and others.

You should apply the right brake system air pressure, which may be enough to make brakes – trailer brakes more powerful and reliable.

This requires you to take technical solutions for your air braking system.

Controlled Braking System

You should press the brakes to avoid locking the wheels. If you need to turn more or you will make the wheels lock. After that, release the brakes.

Stab braking

Stab braking should be applied in your cars without anti-lock systems. You should note these considerations about terms of air brakes in this situation:

  • Use brakes on all the roads.
  • Remember to release the brakes when there are lock-up wheels.
  • Ensure to put on the brakes fully again after waiting one second to roll the wheels.

Stopping Distance From System

You should consider two factors relating to this process: Speed and Stopping distance. If you apply for air or hydraulic brakes, you must not follow the important tips below:

  • Air brakes have an extra delay – the brakes do not work right away when you press the pedal. This is because the air takes some time (at least half a second) to travel through the lines to the brakes.
  • Hydraulic brakes (used on cars and smaller trucks) work faster. You usually apply the brakes as soon as you press the pedal.


air brakes dragging

Why Are Air Brakes Not Releasing Or Slow?

Air brakes may not release or be slow because of various reasons.

Some common causes are: kinked or blocked pipes or filters; corroded brake caliper pistons; sticking or seized brake valves; or incorrect clearance settings.

These problems can affect braking performance and safety.

Which Is The Best Way To Use An Air Brake System?

The best way to use an air brake system is to follow these steps:

  • First, charge the system with air.
  • Apply the brakes smoothly.
  • Control the pressure to stop safely after that.

You continue to start this process by releasing the brakes and finally checking the brakes regularly.

Are Air Brakes More Difficult And Harder To Use?

Air brakes are not necessarily more difficult to use than hydraulic ones, but they require some knowledge and practice to operate safely and efficiently.

Therefore, air braking drivers need to be familiar with their components, functions, and proper usage.


I have just provided you with useful tips about how to manually release air brakes. You should follow the steps above to have better experiences with the brakes in your cars.

If you need more information about trailer or tractor brakes, contact your car experts or post your questions in the online community for good answers.

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