Posted December 16, 2018 by Jefferson Bryant Know How

Know-How Notes: Braided Hose End Guide

Braided hoses are often necessary for high-pressure applications, such as power steering lines and some fuel systems. While OEM application hoses can be purchased assembled, sometime you have to build your own. Most NAPA Auto Parts Stores carry a wide variety of braided hoses and fittings, including the kind that you can install yourself.

There are three common types of these hose ends; compression, threaded, and crimp. Your application, hose type, and equipment will determine what you need to use. Hydraulic hose ends are called JIC or AN fittings. JIC ends are steel, AN fittings are aluminum. They are interchangeable as they both use 37-degree flares (DO NOT attempt to install a JIC or AN fitting onto a 45-degree line, it will ruin both lines and leak). AC hose ends come in several different types, all of which require O-rings to seal.

Crimped Hose Ends

Crimp terminals are the most common type of high-pressure braided hose end that you will encounter. These are assembled fittings that in most instances will require a crimping tool that you won’t have access too, so you have to have the work done for you. The crimping tool is a hydraulic machine that compresses the fitting over the hose, permanently bonding the two parts together. Applications for these hoses are hydraulic or gas (not fuel) transfer hoses, such as power steering, brakes, and air conditioning (A/C).

The key to crimp hose ends is getting the orientation correct. If it off more than a degree or two, you will not be able to install the hose. Always mark you hose and end with orientation marks like this.

Power steering and brake lines require extreme pressure handling, over 2,000 psi. These hoses need the big machine. A/C hoses see much lower pressures, in the 150-300 psi range. These fittings can be assembled with a hand-operated crimping tool.

This crimping tool is reasonably priced, but you need to buy one unless you make a lot of hoses. It does not work for high-pressure hoses like brake or power steering line.

Crimped fittings do not have any type of swivel, so they have to be assembled with the fitting correctly oriented to each other. This can be very real problem if you just guess, because your hoses will not line up. Braided hose is very stiff, it bends, but you can’t twist it. It is always recommended that you take the fittings and the hose to the vehicle, pre-installed the fittings on the hose, lightly thread the fittings to the components, and then mark each fitting to the hose with a marker. Then you can take the parts back to the store and have them crimped in place. This is a critical step that you do not want to skip.

A completed crimp with the machine above looks like this.

Threaded Hose Ends

DIYers can build their own hoses using threaded-style braided hose end fittings that thread together. There is a threaded collar which slides or is threaded onto the hose, which is then pushed onto the main fitting and the assembly is threaded together. These work really well for all high-pressure applications such as power steering. These fittings are not available for A/C, which require crimped fittings. There are most common and easiest to work with hose ends for DIYers. Watch out for your fingers, as the stainless wires will get you and it hurts.

Because these are so common, we have a complete assembly tutorial for you here:

The assembly requires freshly cut hose (not shown), and a fitting. These are Eaton performance fittings in black anodizing.

Using some protective vise jaws, the collar nut is held in the vise, and you push and twist the braided hose into the collar, leave the hose about 1/16" away from the inside lip — Using some protective vise jaws, the collar nut is held in the vise, and you push and twist the braided hose into the collar, leave the hose about 1/16″ away from the inside lip

Wrap some tape around the hose where the collar is. This is used to check how much the hose was pushed out of the fitting.

We switched to some aluminum jaws to protect the finish of the fitting and clamped the hose end down.

To make it easier, we sprayed the nipple side with some WD-40 to keep the hose lubed up.

Push the hose onto the nipple and thread by hand as far as you can go.

Then switch to an aluminum wrench for AN fittings. Tighten the collar until there about 1/16" gap between the collar and the head of the fitting nut. — Then switch to an aluminum wrench for AN fittings. Tighten the collar until there about 1/16″ gap between the collar and the head of the fitting nut.

Measure the gap, it needs to be about 1/16" of an inch, to tight can cause leaks, so can too loose. — Measure the gap, it needs to be about 1/16″ of an inch, to tight can cause leaks, so can too loose.

Now check the tape. The hose can pull out of the collar about 1/8" and still be okay to use, anymore and you need start over. This one didn't budge, perfect! — Now check the tape. The hose can pull out of the collar about 1/8″ and still be okay to use, anymore and you need start over. This one didn’t budge, perfect!

Compression Hose Ends

Compression fittings are similar to threaded fittings, but instead of a nipple inside the main fitting, there is a ferrule. These fittings are commonly used with Teflon braided hoses, which has a hard plastic tube instead of a rubber hose in the center. A threaded collar slides over the hose, then the stainless braid is carefully pulled away from the plastic tube. A ferrule slides over the tube, and the fitting is pressed against the ferrule while the collar is thread to the fitting, compressing the tube, providing a leak-proof seal. These ferrules are typically made of brass, and are one-time use only, you can’t take them apart and re-install them (you will end up with a bad leak if you try). These braided hose end fittings and hoses are commonly used for power steering and brake applications.

Compression fittings for hose are not easy to assemble. The copper ferrule goes directly onto the nylon inner hose, and the outer nut threads onto the main fitting. They seal great, but are tricky to actually get together correctly. These only work for nylon inner tubes, not the rubber stuff.

Building your own hoses is not complicated, but it does require some patience, especially with the compression fittings, those ferrules can be a real bear to work with. When in doubt, visit your local NAPA Auto Parts Store for assistance with building your new hoses.

Check out all the belts and hoses available on NAPA Online or trust one of our 17,000 NAPA AutoCare locations for routine maintenance and repairs. For more information on braided hose end options, chat with a knowledgeable expert at your local NAPA AUTO PARTS store.

Jefferson Bryant View All

A life-long gearhead, Jefferson Bryant spends more time in the shop than anywhere else. His career began in the car audio industry as a shop manager, eventually working his way into a position at Rockford Fosgate as a product designer. In 2003, he began writing tech articles for magazines, and has been working as an automotive journalist ever since. His work has been featured in Car Craft, Hot Rod, Rod & Custom, Truckin’, Mopar Muscle, and many more. Jefferson has also written 4 books and produced countless videos. Jefferson operates Red Dirt Rodz, his personal garage studio, where all of his magazine articles and tech videos are produced.