How to Replace a Hydraulic Cylinder Seal in a Power Team Ram (Without Making It Worse)

Most hydraulic cylinder seal failures I see aren't from normal wear—they're from installation mistakes. If you're replacing a seal in a Power Team hydraulic ram, the job comes down to four things: a clean workbench, the correct seal kit, proper seal orientation, and a pressure test before it goes back into service. In our Q1 2024 quality audit, 78% of repeat leaks traced back to installation issues, not failed seals.

I'm a quality and brand compliance manager at a hydraulic equipment company. I review every returned or rebuilt unit before it reaches customers—roughly 200 items a year. I've rejected 7% of first deliveries in 2024 for seal-lip damage, scratched rods, and missing labels. So I'd rather you slow down now than pay for the same job twice.

Before you order anything: identify the actual ram

If you search for a 'power-team' seal kit without a model number, you'll probably buy the wrong size. There are dozens of Power Team hydraulic rams that look nearly identical from the outside.

The Power Team logo and model number are usually stamped on the barrel or on a metal tag attached to the base. If the logo is faded or painted over, find the model number before doing anything else. On older SPX-era rams, the number may be stamped near the base, not on the decal. If there's no model number and no stamp, take measurements and match them against the service manual.

I also tell customers to buy seal kits through a Power Team distributor. Aftermarket kits can be close on dimensions but wrong on durometer, and that kind of wrong doesn't show up until the ram is under load.

Power Team rams are often paired with pumps that look similar but have different fittings. If the pump's oil is milky or smells burnt, don't bother fixing the ram until you flush the system. New seals won't survive contaminated fluid.

Tools you actually need (and one you don't)

Leave the 836 aluminum pipe wrench in the truck. It's a great tool for pipe work—I keep one in my own box—but it has no place on a hydraulic cylinder. That wrench can crush a thin barrel or scar a polished rod if you use it to hold the cylinder while cracking the gland. Use a soft-jawed vise or a leather strap instead.

Everything I'd read about cylinder repair said you need a full pick set, a dead-blow hammer, and a torque wrench. In practice, the most important tool is a bright light and a magnifying glass. A lot of 'bad seals' are actually debris caught between the seal lip and the gland. You won't see it until you get the gland out and look closely.

A torque wrench is useful, but not for the reason most people think. The gland on most Power Team rams is threaded, and overtightening can distort the gland and pinch the seal. I've seen more damage from over-torque than under-torque.

How to replace a hydraulic cylinder seal in a Power Team hydraulic ram

Step 1: Release pressure, then release it again

The ram might look fully retracted, but it can still hold residual pressure. Crack the hose connection slowly or open the vent plug with your face out of the line of fire. Wait at least five minutes after the gauge reads zero before disconnecting anything. I've seen a 10-ton ram jump a full inch after being 'empty.'

Step 2: Disassemble with the rod horizontal

Mark the gland position and orientation before you loosen it. On most single-acting rams, the gland is the only thing holding the rod in. Supporting the rod with cardboard or a soft bench is not optional. I still kick myself for setting a rod on bare concrete once. If I'd used a stand, the rod wouldn't have got a nick that eventually tore a seal on the way back in.

Step 3: Remove old seals without scratching anything

Use a plastic pick to lift the old seals. A metal screwdriver will score the gland groove, and a scored groove will eat the new seal just as fast as the old one. Zero is the only acceptable surface damage in a seal groove.

If the old seal has chunks missing, find the missing pieces. They can be wedged behind the back-up ring. If you leave them there, they'll score the rod on the first stroke.

Once the seals are out, clean every groove with a lint-free cloth and hydraulic fluid. Do not use a wire brush. If you suspect contamination, check the fluid and the pump before going further.

The conventional wisdom is to replace every seal in the kit. I do not always agree for every cylinder. On a tie-rod cylinder with documented history, replacing only the rod seal can be fine. But for a Power Team hydraulic ram that has been in service for years, replace the entire kit. The second teardown costs more than the seals.

Step 4: Lubricate, install, and check orientation twice

Use clean hydraulic oil to lubricate the seals. Grease can hold grit and make the seal stick. Install the seals with your fingers, not a screwdriver. If a wiper seal gets twisted during installation, it can look fine and still leak. I've rejected a small batch of seals from a vendor because the wiper lip was facing the wrong way. It looked right to a casual eye, but it would have pushed contamination into the cylinder instead of keeping it out.

Don't use a pick to push the replacement seal in. A sharp edge can shave the seal lip without you noticing. If your kit includes back-up rings, install them on the pressure side as shown in the service manual. Seal orientation matters more than how tight the gland feels.

Step 5: Pressure test before you put it back into service

Pressurize the ram to low pressure and run it through a full cycle. Check for leaks along the rod and around the gland. Then hold it at rated pressure for 30 seconds. If it weeps at this stage, it won't heal itself (trust me—it won't). Take it apart and find the cause.

When to stop and call a professional

No amount of careful seal work will fix a bent rod, a dented barrel, or chrome that's flaking off. If you see any of those, stop. Roll the rod on a flat surface: if it rocks, it's bent.

This guide works for maybe 80% of the seal jobs that come through our shop. If you're working on a double-acting cylinder with internal manifolds, a telescopic unit, or a specialty model with a load-holding valve, this process is not enough. You need the specific service manual for that model.

If you're comfortable with chainsaw repair, you can probably handle a ram seal—the skills are similar: clean parts, exact order, small pieces. But chainsaw repair doesn't have 10,000 psi behind it. Respect that difference.

I recommend the full-kit route for most Power Team hydraulic rams. But if your ram has been damaged by a fall, a bent rod, or rust, a seal kit is not the solution. Seals fix leaks, not structural damage.