Valve core removal tools were originally developed to remove damaged valve cores without the need to pump the system down. This technology was a major leap forward in work efficiency, as pumping down a system can be a tedious and time-consuming task.  

Eventually, technicians discovered that removing valve cores led to faster evacuation, recovery, and charging times.

Today, valve core removal tools are quite common, especially when it comes to pulling a quick vacuum. But just like any other tool, quality and maintenance matter. 

In this article, we are going to discuss valve core removal tools, their use and maintenance, as well as some signs that might indicate it is time to rebuild or replace.

The Valve Core

The valve core removal tool (VCRT) has a very specific job. As its name suggests,  it removes valve cores, but it is much more than the old valve stem remover we used on our bicycle tubes as kids. The VCRT is designed to keep the HVAC system sealed while removing the core, but I think to truly respect the value of this tool, it is important to understand what a valve core is, what it does, and why it is crucial to remove it in the first place.

A valve core can be found in service ports in a variety of locations, depending on the type of HVAC equipment you are servicing. However, for the purpose of this article, we will primarily be referring to liquid and suction line service ports as we discuss removing and replacing valve cores.

Service Ports

Service ports give technicians access to the refrigerant contained within the system. Each service port is equipped with a valve core that is basically a door keeping the refrigerant from escaping, but it also gives the technician access to the system's refrigerant for processes like pressure testing. 

Service ports are threaded for the attachment of hoses, probes, and other appropriate tools. Once attached, the hose or tool depresses the valve core stem, allowing access to the sealed refrigeration system. 

In its resting position, the spring-loaded valve core blocks the refrigerant and keeps the system sealed. 

When the valve core is depressed, it allows the refrigerant to pass through a small orifice. This state enables the technician to read pressures or otherwise access the sealed system in a controlled manner.

It is not recommended to attempt to recover refrigerant or pull a vacuum through the valve core. The valve core is essentially a restriction. Not only does it greatly reduce the flow rate of the refrigerant, but it also acts somewhat like a metering device when recovering refrigerant. The recovery process will be slower because refrigerant tends to flash as it passes through the small opening of the valve core, which ultimately causes it to expand and heat up before it enters the recovery tank.  

It has become standard practice for most technicians to remove the valve core prior to any vacuum or recovery procedures. This—in addition to large diameter hoses and a good quality vacuum or recovery pump—has made these processes much more efficient. For more information on evacuation techniques, visit https://hvacrschool.com/videos/evac/

Valve Core Removal Processes and Procedures 

There are lots of different valve core removal tools on the market. No matter which brand you choose, quality should be top of mind. Poor-quality results in leakage, which defeats the purpose of using the tool to begin with. 

There are a few different options available, but at minimum, a valve core removal tool should come with a sealed service port fitting, shut-off valve, valve core capture rod, and a side port for attaching micron gauges.

You can attach the valve core removal tool to the HVAC equipment by screwing the service port fitting onto a service port. This process is critical, as it creates the necessary bond to keep the system sealed. The fitting should be finger-tightened—never use pliers to tighten the fitting even further. If a proper seal is not achieved by finger-tightening, it is likely that the rubber O-ring contained within the fitting is compromised. Using pliers to tighten will only further damage the O-ring.

Once the removal tool is adequately attached to the service port, you can then press the capture rod and turn it counterclockwise until the pressure of the system can be felt pushing on the rod. If the system is empty, then the technician will rely on instincts and experience to feel when the valve core is completely unscrewed. 

With the valve core completely unscrewed, the capture rod can be pulled back until it stops. It is very important to close the shut-off valve at this point. Failure to close the shut-off valve prior to removing the capture rod fitting cap will result in the loss of refrigerant—as well as a high risk of injury. In systems void of refrigerant, there is the risk of introducing unwanted atmospheric contamination, such as moisture-laden air.

Once the valve core has been removed, you can attach a hose.  Slowly open the valve while you listen and check for obvious signs of leaks.

Once you’ve completed service and testing, shut off the valve so that the attachment can be safely removed. Replacing the valve core is simply the reverse order of its removal. 

Valve Core Removal Tool Option

Like any other tool, as the industry progresses, so do the tools associated with it. Valve core removal tools are no exception to this rule. You can find barebones, basic valve core removals that have only the essentials to remove the core—or you can opt to find one with features such as sight glasses and side port valves. 

It ultimately depends on the technician to decide what features they need. The basic models, “as long as they are good quality,” will get you in and out of most jobs just fine. But 

I think there is something to be said about the upgrade to the side port valve. 

This side port valve enables the technician to isolate and protect sensitive micron gauges. Instead of having to remove them after the decay test and risk introducing air to the system, the technician is able to close this valve with confidence before charging the system, protecting the micron gauge from the refrigerant. 

Another big consideration is the capture rod itself. These are not created equally. There are some pretty big disparities between brands as far as the capture rods’ ability to capture the valve core effectively and remove it. This article is not intended to sell any particular brand’s valve core removal tool, but I strongly recommend that you watch some product reviews specifically about the capture rods' efficacy. Some of the brands put out capture rods that are more effective at causing you to pull your hair out in frustration than actually capturing and removing a valve core—while other brands create such a tight bond with the valve core that you can literally dangle the capture rod itself from the valve core. 

We are also starting to see options like sight glasses hitting the market, which gives an added level of confidence to the technician when extracting the valve core. The sight glass allows us to see and confirm that the valve core has indeed been captured and is safe to remove.

Tool Maintenance

The question of when you should rebuild the valve core removal tool comes up pretty often. The simple answer is “when it starts leaking.” Unfortunately, we often discover leaks on the job after we’ve already started the evacuation process. The key to having success with these tools is to be conscious of the fact that the tool’s efficacy relies on little rubber O-rings. These O-rings shouldn’t be expected to last forever. Just like a vacuum pump’s oil should be changed regularly, so should the valve core removal tools’ O-rings. 

The trick is knowing how to get the longest life from a set of O-rings as possible. Pliers are the number-one killer of O-rings in valve core removal tools. As mentioned earlier, the valve core removal tool should only be finger-tightened. Attempting to tighten any further with pliers will squish the O-ring and cause premature failure—if not immediate failure. Over-tightening can also cause the O-ring to obstruct the removal of the valve core. 

The second threat to the O-ring is debris. Dirt or copper shavings can cut into the soft rubber of the O-ring, compromising its ability to properly seal for a deep vacuum.

The third is daily wear and tear. The more you use O-rings, the faster they will wear out. It is recommended to add some vacuum pump oil to the O-rings to help create a better seal, as well as help maintain some pliability.

Rebuilding the Valve Core Removal Tool 

Most reputable valve core removal tool manufacturers offer rebuild kits that are fairly inexpensive. Usually, the kit consists of various-sized O-rings that we simply swap out with the old ones.  

It would be difficult to give specific instructions on rebuilding the valve core removal tool because there are so many different brand options available. However, the technique is pretty consistent across those that have removable O-rings. 

Typically, the use of a bent pick or something similar to extract the O-rings is a pretty common practice. The trick is locating and removing the various O-rings in any particular tool. You will need to refer to the manufacturer’s literature for this information, as they all have variations that just simply couldn't be covered in an article like this. 

One thing that seems to be pretty practical advice is to use a little bit of clean vacuum oil applied to the new O-rings during installation. 

Conclusion

A humble tool that got its beginnings in emergency repairs has ultimately become a vital part of HVAC service. Thanks to the valve core removal tool, pulling deep vacuums, charging, and recovery have all gotten a lot faster. (Now, just remember to use ½” or bigger hoses for vacuum, and you’ve got all the makings of a perfect setup.)

The valve core removal tool also comes in a flavor for everyone—plain and simple or with all the bells and whistles like sight glasses. No matter which model you choose, the key to an effective, long-lasting VCRT is maintenance and taking proper care of the O-rings on the inside. Follow the maintenance steps here, and you’ll have a reliable tool at your side for years to come.

—JD Kelly