Genie S65 Boom Cylinder Rebuild
If you run a Genie S65 and the boom is drifting down, weeping oil around the rod, or just plain won’t hold a load anymore, you’re probably looking at a Genie S65 boom cylinder rebuild. We’ve had more than one of these come through our shop with scored bores and chewed-up piston seals, and it’s rarely a mystery once we pull the cylinder apart. We do this work at our bench in Ames, and we’ve seen enough of these units to know where they wear first and what it takes to get them back to spec.
Genie S65 Boom Cylinder Rebuild Basics
A Genie S65 boom cylinder rebuild isn’t a quick reseal-and-done job. These are big single-stage cylinders carrying real weight up in the air, and the tolerances matter. We pull the cylinder off the machine, strip it down on the bench, inspect the barrel and rod for scoring, and replace every wear part before it goes back together. If you’re comparing this to other rebuild jobs we’ve done, our hydraulic cylinder rebuild cost guide covers the general pricing logic we use across most brands, including Genie.
What’s Inside a Genie S65 Boom Cylinder
Depending on the exact cylinder configuration on your S65, we’re typically replacing a head seal, a piston seal sized around 3″ x 1.062″ x 3.25″, U-seals near 1-1/8″ x 1-3/8″ x 3/8″, and a wiper seal to keep contaminants out of the rod. These aren’t generic parts we grab off a shelf — we match them to the bore and rod dimensions on your specific cylinder before we order.
How We Do a Genie S65 Boom Cylinder Rebuild
Every Genie S65 boom cylinder rebuild we do follows roughly the same sequence, whether the cylinder came off a lift on our own or one that rolled in on a trailer:
- Remove the boom cylinder from the machine and bring it to the bench
- Fully disassemble and inspect the barrel bore and rod surface for scoring or pitting
- Hone or replace the barrel if the scoring is too deep to clean up
- Install a new head seal, piston seal, U-seals, and wiper seal matched to your cylinder’s dimensions
- Reassemble, reinstall the cylinder on the machine, and bleed the hydraulic system
- Cycle the boom under load to confirm it holds and doesn’t drift
We also check the lock cable and lock cylinder while we’re in there, since on a lot of S65 units those parts see the same stress and wear right alongside the boom cylinder.
Common Signs You Need a Genie S65 Boom Cylinder Rebuild
Most customers don’t call us because they read about seal wear online — they call because the machine is telling them something is wrong. Here’s what usually points to a Genie S65 boom cylinder rebuild:
- The boom slowly sags or drifts down when it should hold position
- You see oil weeping around the rod seal or head, especially after the machine sits overnight
- The boom feels spongy or hesitates before responding to the controls
- There’s visible scoring or a rough feel when the rod extends and retracts
- The machine failed an inspection due to cylinder leakage or drift
One thing worth knowing up front: on a lot of these units, once one boom cylinder starts scoring, the companion cylinder on the other side isn’t far behind. It’s really common for the second cylinder to blow out not long after we rebuild the first one, simply because they’ve been running the same hours under the same load. We tell customers this up front so it’s not a surprise later.
How Much Does a Genie S65 Boom Cylinder Rebuild Cost
A straightforward Genie S65 boom cylinder rebuild — remove, rebuild, reinstall, and bleed — typically runs in the range we quote for mid-size aerial cylinders, generally landing between $600 and $1,200 depending on seal availability and how much cleanup the bore needs. If the barrel is scored too badly to save and needs a full cylinder replacement instead of a reseal, add roughly $300 to $800 on top of that, depending on whether it’s a smaller lock cylinder or the full boom cylinder assembly. If we’re also handling a lock cable replacement or lock release cylinder at the same time, that adds parts and labor on top — a smaller lock cylinder alone often runs around $145 plus labor.
If you’re outside a 40-mile radius of our Ames shop, mileage gets added to the invoice; inside that radius, shop lift-out and round-trip mileage for a single technician is usually built into the quote. We try to be upfront about all of this before we start, not after.
We do this same style of work on excavators and skid steers too — if you’ve got a different machine down, our excavator cylinder rebuild page covers that side of the shop, and our hydraulic cylinder repair page has more on general cylinder troubleshooting if you’re not sure yet what’s wrong.
If your Genie S65 is drifting, leaking, or just not holding the boom the way it used to, don’t wait for the other cylinder to go too. Give us a call at 515-292-2599 and we’ll get your Genie S65 boom cylinder rebuild scheduled and back on the job site.
Frequently Asked Questions
How long does a Genie S65 boom cylinder rebuild take?
Most Genie S65 boom cylinder rebuilds take 1 to 3 days at our shop, depending on seal availability and whether the barrel needs honing. If we have the seal kit in stock, it can move faster.
Can you rebuild the cylinder without removing it from the machine?
No — a proper Genie S65 boom cylinder rebuild requires pulling the cylinder off so we can fully inspect the bore and rod. Trying to reseal it in place risks missing scoring that will just fail again.
Will the rebuild hold, or should I just buy a new cylinder?
A rebuild holds in most cases when the bore isn’t scored too deep. If scoring is severe, a rebuild may not hold long-term, and we’ll tell you honestly if a new cylinder is the better call before we start.
Do you come to our site for the Genie S65 boom cylinder rebuild or do we bring it in?
We can do either. If you’re within about 40 miles of Ames, we can send a technician out; farther out, mileage applies. Some customers prefer to trailer the machine or just the cylinder to our shop.
What’s included in the price of a Genie S65 boom cylinder rebuild?
Our quote covers removal, full teardown and inspection, new seals (head, piston, U-seals, wiper), reassembly, reinstall, and bleeding the system. Anything extra, like a lock cable or lock cylinder replacement, is quoted separately.
Written by Josiah Ragsdale, Ames Hydraulics