Air compressors are versatile machines that can provide you with many opportunities to conduct and complete projects at home. However, over the course of time, air compressors will be subject to some issues that require maintenance. This article will focus on air compressor tank leaks and, how to fix them!

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Air Compressor Tank Leak

Air compressor leakages are very common amongst air compressor users, whether that be due to the air hose, loose parts or connections, or even a rust leak in the air tank. We are lucky to have a solution in place that you can follow to fix an air compressor tank leak.

NAPA 10 gallon compressed air tank
NAPA 10 gallons compressed air tank

When you suspect there is a leak in your air compressor system, you must inspect the whole system vigorously to ensure you locate the exact location of the leak. It may very well not be the compressor tank, it could be a number of parts or connections. Visit our Compressed Air Leaks guide to find out how to find and fix leaks in compressed air systems.

If you diagnose your system with having an air hose leak or a quick-connect leak, we have pages dedicated to this on our site! Here, we will discuss an air compressor tank leak. So, you must be wondering, how does an air compressor tank leak?

Well, as you must know already, air compressor tanks are used to store compressed air for use with pneumatic tools and devices. When air is compressed, condensation is a natural byproduct due to the water vapor present in atmospheric air being heated to high temperatures.

When the compressed air sits in the air compressor tank, water is allowed to accumulate. This accumulation of water in the tank, if not drained properly, will lead to the corrosion of the tank and cause it to rust. Now, not only is water moisture and rust being in the air stream an issue (that’s a separate topic) but the corrosion of the tank can eventually cause the development of pinholes in the air compressor tank’s body and water will drip out before air will begin to leak.

These pinholes if not dealt with, will continue to go, and soon your air compressor tank will no longer be able to hold air at sufficient pressure or it will become a great risk to your safety. Therefore, it is ever so important to diagnose and fix these leaks as soon as possible, if possible, otherwise you should seek to buy a replacement compressor.

Blown Craftsman air compressor tank
Craftsman air compressor tank explosion

Warning: Under no circumstances should a badly damaged, or rusted tank be patched, welded, or brazed. The risk of an explosion is too high to risk patching anything other than a broken weld or weak seam.

How to Fix an Air Compressor Tank Leak

In some situations, it may not be safe to conduct a repair on an air compressor tank, and so it may be better to replace the tank, or if the cost is similar, buy a new air compressor. I will strongly advise consulting an expert before going ahead with any repair due to the evident safety hazards.

Before describing the process to you, let’s ensure you have all the necessary tools at hand. To fix an air compressor tank leak you will need the following:

  • Soapy water
  • PTFE tape
  • Wrench
  • Brazing torch
  • Brazing rod
  • Angle grinder
  • Protective gloves
  • Protective glasses

You should already have these tools at home if you’re into your DIY projects, but if not, be sure to borrow or buy whatever you’re missing before following these steps.

I will break the guide into the following 4 steps for ease.

Fixing an Air Compressor Tank Leak Step by Step Guide

  1. Detect the Leak

    I presume you would have already completed this step if you’re reading this page, but for those who haven’t… Turn on the air compressor and fill the air compressor tank. Use the soapy water and apply it around the tank, its valves and, its fittings. If you have a sprayer, this would make the job easier.
    When you apply the soapy water to the tank, look for the occurrence of bubbles, if you detect any then this is where your air compressor tank leak is. However, if the problem is at the fittings only, tighten them with a wrench and run a second test and follow the steps in the next section of this article.
    You should spray the tank gently so that you can cover the whole tank. If you discover bubbles on the body of the tank, it’s likely that you have a pinhole or rust leakage, so proceed onto the next step.

  2. Release the Air

    After identifying the leaking area, turn the compressor off and release the air from inside the tank by opening the drain valve and waiting until all the air has been drained.

  3. Grind the Leaking Area

    Now you have detected the leak and drained the air compressor tank, use the angle grinder to grind the area smoothly until it goes flush and smooth.

  4. Use the Brazing Torch & Rod

    Now, use the brazing torch to apply direct heat on the leakage area and then place the brazing rod on it to rebuild the area. Turn the gas on and use welding lighter to spark the torch into action. Keep heating the area of the leak with the brazing rod until the flame reaches a blue color. Then place the brazing rod metal on the area so that it melts and sets down and seals the tank. Allow the repair to cool completely before turning the compressor on and using it again.

The heat of the brazing torch should remove any additional rust and the leakage area will be covered with the welded metal. You must wear protective gloves and glasses when conducting this method to ensure your own safety when handling the brazing torch as the temperature can be extremely high.

How to Fix an Air Compressor Tank Fitting Leak

One of the main areas where the compressor tank has leaks developing is the hose joints and shut-off valve. A small leak here can cause a significant drop in pressure of your overall system and subsequently, your air tools will not operate as efficiently.

In the case that you run an air compressor tank leak inspection as previously described, and you find that the fittings are the source of your air leaks, you can follow these tips for fixing a leak between the tank and hose:

  • tighten any leaking hose joints and fittings (check with soapy water, or even better, an ultrasonic detector)
  • if necessary, cut hose just above the tank fitting and place a new compression ring here
  • fit a wrench to the nut of the pressure valve and rotate it clockwise to release pressure
  • use PTFE tape and wrap it around the threads of the new valve fitting, use a wrench on the compression ring and turn it counter-clockwise to tighten the nut
  • check again by either applying soapy water or using an ultrasonic detector, if the problem persists then replace the fitting again in the same way until you have no signs of a leak

FAQs (Frequently Asked Questions)

Can a leaking air compressor tank be repaired?

It is possible to repair small pinholes if they are on a broken weld or a weak seam. You can do so by welding or brazing the area. It is, however, not recommended to repair larger-sized holes or pinholes elsewhere that are caused by rusting or a generally badly damaged compressor tank.

Can you weld a leaking air compressor tank?

Yes, but only if you’re welding a broken weld or a weak seam. The risk of an explosion is too high to use an air tank that has been badly damaged or is rusted, so it is not advised to weld or patch the air compressor.


If you have any questions about how to fix an air compressor tank leak, please leave a comment below, with a photo if applicable, so that someone can help you!