Skiving a hydraulic hose is really about reliability. The right thing to do is to skive it if you’re using reasonable fittings. It allows the fitting to bite into the braiding rather than simply rest at the top, the cover. If that cover peels back or pulls off, you’re going to have failures. For hydraulic applications where reliability and safety is paramount, that’s the main reason you really should skive.
Skiving is the process of removing the outer cover and sometimes the inner cover. The thing about skiving is that you need special equipment. The whole idea with skiving is it allows you to use those reusable fittings. A machine spins around and removes a bunch of material, makes a bit of a mess. The idea is that when you use a reusable hose fitting, you have the two-piece hose fittings that you can install in the field; if you have a broken hose in the machine, you can splice in an attachment or just get yourself by until you can get to a hose shop and get a proper hose made.
Once you cut your hose, you have the hose side, the fitting side, and attach them together. The hose side goes around in a left-handed thread. The idea is that if it’s skived, you don’t have to push this threading through the cover of the hose, so not only is there more friction, but it bites into the rubber. You want those teeth to bite into the braiding itself, as that’s going to be the strongest connection. Once you have that threaded on, after it’s skived, you put in the fitting side, and that will push the hose outward to the teeth that are on the hose side fitting. That allows you to have a secure bite into the hose.
If you do try to use reusable fittings on hydraulic hose, as the hose warms up, what happens is the rubber becomes softer and more likely to release that soft material—because the hose side will not bite all the way into the braiding if you have the cover still attached to the hose. It will pull the entire thing off the braiding because it never actually bit down into it. This gets worse as the hose heats up. With any hydraulic application, obviously, hydraulic oil heats up and you’ll soon have an unreliable hose.