How to Relieve Hydraulic Line Pressure

Hydraulic Pressure

Not everything with tractor ownership is a breeze. One of those things is hydraulic couplers. There are many times that these things can be frustratingly difficult to get connected. In fact, I can't get mine connected out here today. Now, I'm not the slightest bit surprised that I'm having trouble with these things today. When you're dealing with a hydraulic coupler, it's quite a lot different than an airline. If you've used an air chuck before, they're very easy to connect. And when you've got a little bit of pressure in those airlines, it's pretty easy to overcome that air pressure in there. You can always connect those couplers together and compress that air a little bit more. Fluids, though, are incompressible. Last time I had these hoses connected, it was about 40 degrees outside, and I then unhooked them and I've now let them sit out here on this nice sunny day. It's 72 degrees, sunny outside, and these hoses are actually a little bit warm to the touch just because they're black out here with the sun on them. Because of that, we start to get some pressure built up inside of these hoses, enough pressure that I can't overcome that when connecting these Pioneer couplers down into this valve manifold. There's a couple of things that we can do here to try to get these hoses connected.

Relieving Tractor Side Pressure

I usually will start by seeing if I can relieve pressure from the tractor side of this couple equation from your male and female. Before I start messing around with the hoses, right, we want to eliminate a problem on the tractor side first. That's usually very easy, right? With your machine shut off, you go through and work your loader valve if you're trying to get your loader coupler connected, or in the case of the third function that I'm fighting with here, turn the run on on your tractor and then move your third function control so you can hear those solenoids clicking to make sure that you drop any pressure out of the tractor side. But if you can't get that side connected, you're going to have to move on to working with the hoses themselves.

Safety Precautions

There are two techniques that you often will see when it comes to having to bleed some of the pressure out of these lines to get your Pioneer couplers to connect again. Now you want to be really careful when you're working with hydraulic fluids under pressure. If you want to be disgusted, go to Google and type in hydraulic fluid injection. Can do all kinds of really disgusting things to your hands if you have a high pressure hydraulic fluid shoot out and get under your skin. You're definitely going to want to try to stay away from places that fluid might shoot out. Wearing safety goggles is going to be a good idea so that you don't get it splashed up into your face. But remember, we're dealing with a fluid here that's under pressure.

Also think through what is on the other end of these hoses. So, if you have, say a hydraulic cylinder that's connected to the other end of a hose that's under pressure, some of that pressure might be coming from the implement itself, right? And when you go and unscrew that hydraulic fitting and that hose is now open, that hydraulic cylinder can close, fluid can come out, but more importantly, you could get trapped underneath of something. Say I was trying to take my loader here, which is part way up in the air, and taking that coupler off, that could cause a real safety issue. So, think through these things right here, "Am I needing to wear safety glasses? Do I need to watch if my loader is going to drop?" There are some safety considerations when going through and opening up these lines.

Relieving Hose Pressure

Once you've fitted your super nerd safety glasses here, right, the more nerdy they are, the better they're going to work, you're going to want to go and loosen your couplers. Now, I prefer to do this from the end of the tractor that the manifold is on as opposed to trying to loosen, say the loose end of the hose. It's going angle around on me, right? You can do this from either side. In this case, the manifold side's going to be a lot easier. This is not the right tool for the job. I'm at home and I don't have large enough tools in order to work on this. Because normally I would be doing these kinds of things in the shop, but this is what we've got to work with here today. We're going to take this, and it usually doesn't take much, just a little bit of counterclockwise motion here and you'll start to see some fluid drip out from around the coupler.

You notice not much dripped out of those lines, right? It doesn't take a whole lot of fluid to drip out of here in order to relieve that pressure. Now, previously I was sitting here putting all my body weight on top of these things, trying to get them connected so I didn't have to go to the garage for tools, and look how easy it is now to put them on, right? Pioneer couplers, when they're not under pressure, are a piece of cake to connect. Just like doing an airline, pull back the collar, push it on, away you go. But on a day like today when you've had, say a 40, 50 degree swing in the outside temperature, it doesn't take a whole lot of heat for these things to build pressure and be next to impossible to connect. So, go grab the tools, the right tools, not channel locks. Kill me down in the comments about it, I know. Crack that open and let those couple of drips of fluid out and off you go.