Symptoms Of Bad Air Governor: Is My Air Governor Bad? (Guide)

Not all air compressors have governors. You will find that a normal air compressor used to power tools does not have one. But your vehicle or RV will have one when you have air brakes. It is an important device that vehicles cannot do without. Keeping the governor working right is vital if you want to stop safely

There are two main symptoms that tell you when your RV’s or other vehicle’s air governor is bad. One will be air leaks, which you should be able to hear. The other is over-pressurization. The latter problem requires replacing the air governor.

To learn more about this problem, just continue to read our article. It has the information you want to know about so you know when your air governor is going bad and needs to be worked on. Take a few minutes to see how this information can help you solve your air compressor governor problem.

What is An Air Governor?


Most people just buy and drive and that means they do not have a clue about the inner workings of their vehicle or RV. This is not a bad thing because not everyone is a mechanic or likes working on mechanical devices.

But everyone should have a working knowledge of the inner parts of their vehicles. That way they will know if some mechanic is overcharging or lying. To understand what an air governor is, look at the word governor.

That term means oversee & controls (one meaning), and that is exactly what it does with your air compressor. It oversees the amount of PSI inside the system. Another word and a better one would be monitors.

The air governor monitors the PSI inside the air compressor and controls the levels. If the air pressure is too low, then it starts the air compressor to pump up that level. If it sees that the PSI is too high, it activates the release and has the air compressor expel some of that air pressure.

It is a very simple but very important task. It is a safety device working hard to keep you and your family safe when you are braking.

How do I Know If My Air Governor is Bad?

How do I Know If My Air Governor is Bad

There are ways to tell if your air governor is going bad. One is that your air compressor never turns off. It just keeps cycling every few seconds. Another way to tell would be that the air compressor never turns on.

The air governor is reading that there is plenty of PSI inside the compressor so it never activates the on the switch to produce more air pressure. There are other signs you can both see and hear that let you know when this device is going bad on you. Those signs include the following:

- Both air gauges stay still for many minutes.

- You experience fast cycling from the wet tank.

- The truck builds up too much or too little pressure.

- You can hear a percussive sound coming from the safety valves.

If your governor is going bad, then you should replace it as quickly as possible. Letting it remain in your system only puts you and your family at risk as your air brakes may not work that well or they will work too well.

If you are not sure it is going bad, have a mechanic do a routine check to make sure it is fine.

Signs And Symptoms Of a Bad Air Governor


Some of the following are also signs that you have a bad air compressor. Since many of the symptoms are the same for all parts of this device, sometimes it may be hard to tell what is wrong. Then the wrong part gets replaced.

Then people are surprised why these symptoms or signs still continue. Usually, these symptoms indicate the governor is bad but it is not always the source of these signs:

- Truck not building air pressure

- The compressor won’t start

- Compressor won’t stop

- Unusual sounds

- Warm air

- Air leaks

- Electrical problems

To tell if you are not building any pressure, time the cycle. It normally only takes 45 seconds for the air compressor to build between 80 and 150 PSI. If yours takes longer than that, then your air governor may be bad.

The cost to repair the air compressor is quite high as it ranges between $800 and $4500. It is a lot cheaper to replace the governor as you may only spend between $30 and $50 for a new one.

If the governor is not the problem, then you know to keep looking until you find the failed part.

Air Governor Bad Unloader Valve


The name tells you exactly what this valve does. Its job is to unload the extra PSI inside the air compressor. As it does this, the motor starts up to build up the air pressure once again when it needs to. This is a never-ending cycle.

If the unloader valve goes bad, then you will have a problem with your air compressor. What causes the unloader valve to malfunction is the accumulation of carbon and other debris.

Fortunately, this is not a difficult malfunction to correct. You just need to clean the valve and re-lubricate it so that it works like new again. That is all there is to this problem.

Of course, the valve may get so bad that it would need replacing but you can avoid that if you check it regularly. Keeping this valve clean will help you preserve your air compressor and have it last for a long time.

This is why you need to check other parts and not just the governor. The same symptoms could indicate that a different part is the source of your problems. Individual parts and replacing them yourself may be the best way to fix your air compressor.

Why Does My Air Governor Leak From The Exhaust Port?


This is due to faulty installation and not a p[art that has failed on you. Before we provide the answer to this question, let’s just say that it is easy to make this mistake, especially if you are not a true mechanic.

Even then true mechanics will make this mistake, as well as designs of parts, are not always clear and easy to understand how they go. When you hear air coming out of the exhaust port it means that someone installed the governor is plumbed wrong or on backward. At least something is not on the right way.

The fix for this problem is to swap the lines on the governor and have the air exhausted in the right direction. This is a simple fix that just about anyone can do as long as they keep track of which line is which and they keep track of which ones go to which port.

It is easy to make the same mistake twice if you lose track of where the hoses go. This bad plumbing tends to bypass the air dryer leaving the exhaust port the only possible exit for the air to use.

How To Test The Air Governor


If you have checked other parts, like the air dryer, the unloader, and so on and they are all fine, then you need to test the governor to see if it is the problem. Usually, the process of elimination will get you to the problem part.

But you should do the following tests to make sure it is the governor that is bad before you go out and buy a new one. Here are the tests you need to do to make this determination:

- Pump the system down so it’s above 80 PSI

- Engage the throttle a little to see if the PSI increases

- If so, you know the compressor working properly in the load phase

- Pump up to max pressure

- When it reaches the highest point, watch for the needles to stop increasing

- Air dryer should purge

All of these steps should occur as you would expect them to. If just one fails the test, then you know your governor is bad and you will either need to repair it or replace it.

If you are not mechanically inclined or at that age where you can’t check out the governor, then take your RV or other vehicles to the right shop to have it looked at.

Some Final Words

Air brakes are a great braking system. They are powerful enough to slow down big rigs and RVs when working right. Before you descend a mountain slope, always stop at the peak and check your air brakes to make sure they are working properly.

Always do regular maintenance on your air brake system. Clean the unloader so it does not get too dirty to function. Also, check your air dryer and other parts to make sure your air brakes will be there when you go down those tough, steep mountain slopes.

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