From its not-so-humble beginnings as an American military tool dating back to World War II, the AN fitting has today become the standard in automotive performance plumbing. The AN thread specification comes from a joint standard agreed upon by the US Army and US Navy (thus the “AN” connection to the name) and ranges from -2 to -32 in 1/16-inch increments. Those increments are measured as the outside diameter (OD) of the tubing, but does not specify the inside diameter (ID) of the tubing since tube or hose wall thickness can and does vary. AN fittings use a 37-degree flare to form a metal-to-metal seal and can be used with either hard line or flexible hose.
Flexible stainless-steel braided hose is great in terms of sealing capability and flexibility for routing but can be a bear to assemble. The other solution is to use hoses with swaged-on fittings that are not reusable and require hose dimensions to be scienced-out to the exact length required – not exactly an easy task to do when underneath a vehicle or contorted into an impossible position while measuring dimensions.
In fact, bloodied fingers can be seen and numerous expletives can be heard within earshot of any shop where performance hose is being assembled – unless that shop is using the hose assembly tools from Koul Tools. They are designed to take the drama out of the process and return sanity to the person installing the hose assemblies.
The company offers a variety of tools designed to help the enthusiast, shop or mechanic put AN assemblies together quickly and efficiently, while saving a ton of time and a lot of unnecessary angst in the process. How much angst? Read on to find out just how simple these tools make the process, and you’ll wonder why they aren’t in your toolbox yet.
Pain And Misery On Assembly
There are a number of ways to assemble reusable AN fittings without using any special tools, nearly all of which involve cutting the hose to length and then attempting to twist it into the hose socket without cutting up your fingertips or wrecking the hose in the process. We’ve seen people using a cut-off wheel, a super-sharp chisel, a hacksaw and various other ways to trim the hose to length. None of these methods address the actual assembly of the hose and fittings, which has always been a labor of hate.
When the hose is cut, due to the braid the ends of the hose can become frayed, and this is where the bloody fingers came into the picture in the past – trying to stuff the frayed ends of the hose into the fitting’s socket, then screw in the center section of the fitting, was horrific enough to cause many a racer to swear off this type of hose assembly altogether.
The problem no longer exists as Koul Tools has developed its AN Hose Assembly tools, which are available from -4 to -16 sizes in a variety of kits designed to satisfy the needs of the enthusiast and racer. The tools themselves are manufactured from a high tech composite that resists wear and simplifies the assembly process by holding the fitting’s socket in place – and in the process, won’t mark up the beautiful new fittings you just spent a pile of money on.
Koul Tools Install Tips
- Make sure to use the proper spacer or shim to ensure the fitting can’t spin in the tool
- Use a few drops of oil in the conical entrance of the Koul tool
- Twist the hose into place, don’t just push it straight in
- It’s possible to over-install the hose; if so, just twist it back out to the proper depth
- Ensure the fitting is snug in the capsule, use adapters if necessary
“I was actually working on installing a twin-turbo Northstar engine into a Graham Hollywood, and there was an immense amount of plumbing involved in building this car,” remembers Raczuk. “There are times where you can cut a stainless line and it slips right into place, but other times when you cut it, it frays all over the place; with our tools it doesn’t make a difference.”
The tool is placed into a vise with the socket portion of the fitting inside. Then, the funnel section of the assembly tool allows the builder to screw the hose right into the socket without ever touching the ends of the hose, and never so much as nicking a fingertip in the process.
Once the hose is installed into the socket, the hose end gets placed into the vise to secure it and prepare it for installation of the fitting itself. It’s recommended at this point to have a set of aluminum jaws for the vise to prevent marring up the fitting, or electrical tape can be wound around the fitting to protect it from damage.
We’ve even seen people wrap the fitting in thin fabric to protect it, but it’s always advisable to have the proper tools for the job. A set of AN wrenches is also preferable to avoid marring the finish.
Complete Solution For Push-Lock Hose
One item gaining popularity with racers over the last several years is the push-on style hose, which simplifies the installation process by removing the socket from the equation and taking the stainless steel out of the picture to offer a substantial weight savings.
The push-on hose is accepted by NHRA and the other major sanctioning bodies for use, but much like the stainless-steel hose, was difficult to install at best. Raczuk saw a need for a complete tool to perform the installation job from end to end, and thus the EZ-On Hose Press was born.
In the past, installing the push-on hose was a challenge; although it would seem simpler than the stainless-braided design, holding the fitting in place and pushing the hose on without marring the fitting was another huge challenge – so Koul Tools developed a super-simple solution in the form of their investment-cast-steel EZ-On Hose Press.
The manufacturer recommends that you boil water, then put the hose into the water until it reaches 200 degrees. Then you’re struggling with this 45 degree fitting and a hot hose – give me a break! – Dick Raczuk, Koul Tools
The Hose Press is delivered with adapters from -4 to -16 AN fitting sizes and is so simple in operation you’ll wonder why you didn’t design it yourself. Each adapter is color-coded and fits only one size of hose.
The Hose Press holds the push-lock fitting in place, then clamps the hose in between a pair of ribbed jaws with simple adjustment wheels. Simply place the adapter in place in the jaws, sit the fitting in place, put a bit of oil on the fitting and inside the hose, and clamp the hose into the press jaws. A simple 17mm socket on the end of a small air gun or even an electric drill makes quick work of the assembly process – just check out the video below.
How To Use The EZ-ON Hose Press