Rebuild or replace a hydraulic cylinder? How we make the call

It's the first thing almost everyone asks when they call: is it worth fixing, or should I just buy a new one? There's no answer that fits every cylinder, but there is a pretty consistent way to get to one. It starts with taking the cylinder apart and looking at two parts: the barrel and the rod.

The barrel decides most of it

Seals are cheap. The barrel is not. Once the cylinder is open we look at the inside of the tube for scoring, pitting and wear. Light marks can usually be honed out. Deep scoring, a tube that has swelled or gone out of round, or a crack near a port or a weld, and the math changes fast, because now you're paying for a new tube on top of the labor.

That matters more on a welded cylinder than on a tie-rod. A tie-rod cylinder comes apart with a wrench. A welded one has to be cut open and welded back up, so a bad barrel on a welded unit is often where we start talking about replacing it.

Then the rod

A rod with a slight bend can often be straightened. Chrome that's pitted or flaking can be polished if the damage is shallow, or sent out to be re-chromed if it isn't. The test we give customers is simple: run a fingernail across the bad spot. If it catches, a new seal won't last long riding on that surface.

Re-chroming adds a few days because it goes to a partner shop. Sometimes that's fine. If the machine is your only loader and it's sitting, sometimes it isn't, and that goes into the decision too.

What a new cylinder really costs you

The price of a new cylinder is only half the comparison. The other half is how long it takes to get one. Common sizes for ag and light industrial equipment are often on a shelf somewhere. Cylinders made for a specific excavator, loader or forklift mast usually come through the dealer, and that can take weeks.

So when someone asks rebuild or replace, we're really comparing three things:

• The rebuild price, including whatever the barrel and rod need.
• The price of a new cylinder, OEM or an exact-fit aftermarket one.
• How many days the machine sits waiting for each option.

If a new one costs about the same as the rebuild and it's in stock, we'll tell you to buy it. We'd rather lose that job than sell you a rebuild that doesn't make sense.

When we'll tell you to replace it

• The barrel is cracked, bulged, or scored too deep to hone.
• The rod and the barrel both need major work on the same cylinder.
• It's an inexpensive standard-size cylinder and there's a new one available locally.
• It has been rebuilt several times already and the mounts or rod ends are worn out.

When a rebuild is the better deal

Large cylinders, welded cylinders on heavy equipment, telescopic cylinders from dump bodies, and anything that's hard to source new. In those cases a rebuild usually saves real money and, just as often, weeks of waiting. Once it's rebuilt, it goes on the pressure-test bench before it goes back on the machine.

Not sure which side yours falls on? Send us a couple of photos and the measurements. Here's what to send for a quote, and here's how our hydraulic cylinder repair in Denver works.