Hyster H120 Lift Cylinder Rebuild
If your Hyster H120 forklift is losing lift height overnight, creeping down under load, or leaving oil puddles under the mast, you’re probably looking at a Hyster H120 lift cylinder rebuild. We’ve had this exact model come through our shop more times than we can count, and the failure pattern is almost always the same: seals give out first, and if the piston or barrel has already started scoring, a seal kit alone won’t save it.
How We Handle a Hyster H120 Lift Cylinder Rebuild
A Hyster H120 lift cylinder rebuild isn’t a quick seal swap — it’s a full teardown, and we treat it that way every time. Here’s what actually happens at the bench:
- Pull the cylinder off the mast (usually requires draining the hydraulic circuit first)
- Disassemble the barrel, piston, and rod end completely
- Inspect the bore for scoring, pitting, or chrome wear on the rod
- Machine or hone the bore if it’s salvageable, replace the barrel if it’s not
- Install new seals — for the H120 that’s typically a head seal, piston seal, U-seals, and a wiper seal sized to the bore
- Reassemble, reinstall on the mast, and bleed the system to get all the air out before we run it under load
We stock common seal sizes for this application — head seals around 3″ x 0.062″ x 3/16″, piston seals near 3″ x 1.062″ x 3.25″, and wiper seals in the 1-1/2″ x 3″ x 5/16″ range — so we’re not always waiting on a supplier to finish a Hyster H120 lift cylinder rebuild. If your unit needs a nonstandard size we’ll order it, but we try to keep the wait down.
Common Symptoms That Point to a Lift Cylinder Problem
Not every mast issue on an H120 means you need a full rebuild, but these symptoms almost always do:
- Forks drift down slowly with the load raised and the lift lever neutral
- Visible oil weeping from the rod seal at the top of the cylinder
- Jerky or uneven lift, especially near full extension
- Lift speed noticeably slower than it used to be, even with good pump pressure
- Metal shavings or discoloration in the hydraulic fluid when you check it
Scoring inside the barrel is the thing we watch for most. Once the bore is scored, seals wear out fast no matter how good the kit is — that’s the reason a Hyster H120 lift cylinder rebuild sometimes turns into a full cylinder replacement mid-job. We’ll always tell you before we go that route, not after.
Why the Other Cylinder Sometimes Fails Right After
On dual-cylinder mast setups it’s genuinely common for the second cylinder to blow out shortly after we finish the first Hyster H120 lift cylinder rebuild. Both cylinders have been running the same hours under the same loads, so if one has scoring or worn seals, the other is usually close behind. We’ll check the second cylinder while the mast is already apart — it saves you a second trip and a second labor charge later.
How Much Does a Hyster H120 Lift Cylinder Rebuild Cost
Pricing depends on how far gone the cylinder is when it hits our bench. For a straightforward Hyster H120 lift cylinder rebuild — good bore, just worn seals — you’re usually looking at a few hundred dollars in labor and parts. If the bore is scored and needs honing or a new liner, add to that. And if scoring is bad enough that the barrel can’t be salvaged, a full new cylinder typically adds $300 to $800 on top of rebuild labor, depending on the part’s availability.
We also charge shop mileage if we’re coming to your site instead of you bringing the machine in — generally a flat rate for round trips within about 40 miles of our Ames location, no trailer needed for most H120 jobs. If you want a broader breakdown of what drives cylinder rebuild pricing across brands, our hydraulic cylinder rebuild cost guide covers the variables in more detail.
Every Hyster H120 lift cylinder rebuild quote we give includes removal, teardown, machining if needed, new seals, reinstall, and a full bleed of the system before we hand the forklift back. We don’t nickel-and-dime you with surprise line items after the fact — if something changes mid-job, like the bore being worse than expected, we call you before we keep going.
Serving Ames and Central Iowa
Most of our Hyster H120 lift cylinder rebuild work happens right here at our shop on Freel Dr, but we also handle on-site cylinder work for shops and yards around the region. If you’re outside Ames, take a look at our hydraulic cylinder rebuild coverage across Iowa or our Winterset cylinder repair page to see if we’re already working near you.
Whether it’s a leaking seal, a scored bore, or a mast cylinder that’s just tired after years of daily lifts, we’ve done enough of these to know what to check first and what usually goes wrong. If your Hyster H120 is losing height or leaking oil, give us a call at 515-292-2599 and we’ll get you scheduled for a look — and a straight answer on whether it’s a rebuild or a replacement before we ever pull it apart.
Frequently Asked Questions
How long does a Hyster H120 lift cylinder rebuild take?
Most take one to two days once the cylinder is on our bench, depending on whether the bore needs machining or we’re waiting on a specialty seal size. Straightforward rebuilds with good bores can sometimes turn around same day.
What causes a Hyster H120 mast cylinder to leak?
Worn head seals or wiper seals are the most common culprit, usually from age and hours of use. If the leak comes with slow drift-down under load, there’s a good chance the bore has started scoring too.
Can you rebuild a Hyster H120 lift cylinder on-site instead of bringing it to the shop?
In some cases yes, especially if it’s just a seal replacement without scoring. But if the bore needs honing or machining, we usually need the cylinder here on our bench. Call 515-292-2599 and we can tell you which applies to your situation.
How much does a Hyster H120 lift cylinder rebuild cost?
A basic rebuild with a good bore usually runs a few hundred dollars. If the barrel is scored and needs a full new cylinder, expect $300 to $800 more on top of standard rebuild labor.
Do you stock seal kits for Hyster H120 cylinders?
We keep common sizes on hand, including head seals, piston seals, U-seals, and wiper seals sized for this cylinder. If your unit needs something less common we’ll order it, which can add a day or two to the job.
Written by Josiah Ragsdale, Ames Hydraulics