Symptoms
- Seat slowly drops after sitting down
- Chair height adjustment lever doesn't hold position
- Chair sits at lowest setting no matter what
Likely causes
- CommonWorn gas lift cylinderThe pressurized cylinder that holds height loses its seal over years of use.
- PossibleDamaged height adjustment lever or valveA broken lever can keep the valve stuck open, letting the seat drop.
- Less commonCracked seat mounting plateThe plate connecting the seat to the cylinder can crack under heavy or uneven weight.
What to do
- Confirm the issue is the cylinder by trying the lever multiple times; if it never holds any height, the cylinder is likely bad.
- Flip the chair over and note the cylinder's diameter and the seat plate style to buy a matching replacement.
- As a temporary fix, wrap a hose clamp or the specific 'chair cylinder sleeve' fix kit around the cylinder at your preferred height.
- For a full fix, remove the seat by tapping the mounting plate loose, then pull the old cylinder from the base with a rubber mallet.
- Insert the new gas cylinder into the base and press the seat back onto the top of the cylinder firmly.
- Test the height adjustment lever to confirm the new cylinder holds position correctly.
Tools and parts
- Rubber mallet
- Pipe wrench (optional, for stuck cylinders)
Office chair gas lift cylinderSearch: “office chair replacement gas cylinder”
Chair cylinder height fix sleeveSearch: “office chair cylinder repair sleeve kit”
When to call a pro
If you're not comfortable removing the seat and cylinder yourself, an office furniture repair service or handyman can swap it quickly.
Safety
Use caution
Removing a pressurized gas cylinder can release force suddenly; keep hands clear of the pinch point and don't attempt to disassemble the cylinder itself.