If you've spent more than five minutes working with old iron, you know a leaking bobcat 743 lift cylinder can turn a productive afternoon into a greasy mess of hydraulic fluid and frustration. The Bobcat 743 is a legendary machine—it's the workhorse that arguably put skid steers on the map for a lot of guys—but even the best machines eventually start showing their age. Those lift cylinders work incredibly hard, and after a few decades of pushing, lifting, and grading, they're bound to need some TLC.
The 743 is a simple, honest machine. There aren't a lot of fancy electronics to go haywire, which is why so many of them are still running today. But that simplicity means the mechanical and hydraulic components take the brunt of the abuse. When the lift cylinders start to go, you'll notice it pretty quickly. Maybe it's just a slow drip at first, or maybe your loader arms start "drifting" down while you're trying to hold a load of gravel. Whatever the case, ignoring it usually just leads to a bigger repair bill down the road.
Recognizing the Signs of Trouble
You don't always need a massive puddle on the garage floor to know your bobcat 743 lift cylinder is struggling. One of the first things you'll probably notice is a loss of power or a certain "sponginess" when you're trying to lift something heavy. If the internal seals are bypassing, the oil isn't staying where it's supposed to, and you'll find yourself having to constantly "feather" the controls just to keep the bucket level.
Another dead giveaway is the "drift." You lift the arms up halfway, let go of the pedals, and watch as the arms slowly sink back toward the ground. That's a classic sign that the piston seal inside the cylinder is worn out. The oil is leaking past the piston from the high-pressure side to the low-pressure side, and that's a clear signal that it's time to crack that cylinder open.
Then there's the obvious one: the external leak. If you see hydraulic oil running down the side of the cylinder or soaking the front of the machine, the gland seal (the one that wraps around the chrome rod) has bitten the dust. This is usually caused by dirt, grit, or even a tiny nick in the rod that tears the seal over time.
Should You Repair or Replace It?
This is the big question everyone asks. A brand-new bobcat 743 lift cylinder isn't exactly cheap, but then again, neither is your time. If the chrome rod is in good shape—meaning it's shiny, smooth, and doesn't have any deep scratches or pits—a simple seal kit is usually all you need. You can pick up a seal kit for a fraction of the cost of a new cylinder, and if you're handy with a wrench, you can do the job in a few hours.
However, if you pull that rod out and see that it's pitted or bent, or if the inside of the cylinder barrel is scored up, a seal kit is just a Band-Aid. You might get it to stop leaking for a week, but those imperfections will chew through new seals faster than you can say "hydraulic failure." In that case, you're better off just buying a complete replacement cylinder. It's a bigger hit to the wallet upfront, but it'll save you the headache of doing the job twice.
The Nitty Gritty of Rebuilding a Lift Cylinder
If you decide to tackle the rebuild yourself, there are a few things you should know before you start. It's not a "hard" job, but it can be a stubborn one. These parts have been together for thirty or forty years, and they don't always want to come apart.
Getting the Cylinder Off (The Hard Part)
The first hurdle is usually the pins. On a Bobcat 743, the pins holding the lift cylinder in place can become one with the machine over time. Rust and old grease turn into a sort of "mechanical weld." You'll want plenty of penetrating oil, a heavy sledgehammer, and maybe a torch to get things moving. Don't be surprised if this takes longer than the actual seal replacement.
Once you get the hoses disconnected (make sure you've relieved the pressure first—nobody likes a hydraulic oil bath), you can haul the cylinder over to a sturdy workbench. You're going to need a big vise. I'm talking about a real, heavy-duty bench vise, because you're going to be putting some serious torque on that gland nut.
Tearing it Down
To get inside the bobcat 743 lift cylinder, you have to unscrew the gland nut at the end of the barrel. Most guys use a large pipe wrench or a specialized spanner wrench. If it's stuck, a little heat on the outside of the barrel can help expand the metal just enough to break it loose.
Once the gland is out, the rod and piston assembly should slide right out. This is the moment of truth. Wipe everything down and look at that chrome rod. If it looks like a mirror, you're in luck. If it looks like a piece of sandpaper, you've got work to do. Replacing the seals themselves is pretty straightforward—just pay attention to the direction the old ones were facing. If you put a U-cup seal in backward, it's not going to do much for you.
Why Good Maintenance Saves You Money
The best way to deal with bobcat 743 lift cylinder issues is to prevent them from happening in the first place. I know, it sounds like a chore, but it's true. The biggest killer of hydraulic seals is contamination. Dirt and grit get on the chrome rod, and then the rod carries that grit right past the wiper seal and into the delicate internal components.
Keep your machine clean. If you've been working in the mud or dust, give the cylinders a quick wipe-down at the end of the day. More importantly, keep your hydraulic fluid clean. If your oil looks like chocolate milk, it's full of water and debris that will eat your seals from the inside out. Change your filters regularly—it's the cheapest insurance you can buy for your Bobcat.
Also, don't ignore the grease zerks on the cylinder ends. If those pivot points get dry, they create extra friction and heat, which puts unnecessary stress on the cylinder itself. A few pumps of grease every few hours of operation goes a long way.
Wrapping Things Up
The Bobcat 743 might be an old-timer, but it's still one of the most capable little machines ever built. Keeping the bobcat 743 lift cylinder in good working order is just part of the deal when you own one. Whether you're just swapping out some crusty old seals or replacing the entire unit, it's worth the effort to keep the machine lifting strong.
At the end of the day, these machines were built to be fixed. They weren't designed to be disposable, which is why we're still talking about them decades later. Take your time, use the right tools, and don't be afraid to get a little hydraulic oil on your hands. Once you get those cylinders sealed up tight, your 743 will be back to work, ready to move whatever you throw at it. It's a satisfying feeling to see those arms move smoothly again without a drop of oil hitting the ground—and your driveway will probably thank you too.