A sinking chair usually has a failing cylinder.
Lubricant cannot repair an internal seal.
Quick answer
Cylinder replacement restores normal height adjustment.
A rigid spacer only locks one chosen height.
Confirm the problem
Rule out the height lever first.
- Check whether the lever stays pressed.
- Inspect the lever linkage.
- Test the chair without sitting.
- Look for visible cylinder damage.
Best fix: replace the cylinder
Replacement preserves normal height adjustment.
- Match the cylinder dimensions.
- Choose a compatible taper.
- Use proper removal tools.
- Follow the chair instructions.
- Test stability before use.
Temporary fix: add a rigid spacer
A spacer prevents downward cylinder travel.
- Choose the final seat height.
- Use suitable rigid tubing.
- Keep the spacer centered.
- Inspect it for cracking.
- Expect height adjustment to stop.
Why lubricant does not fix sinking
Lubricant may help external moving parts.
- It cannot rebuild the internal gas seal.
- Overspray can reach upholstery.
- Slippery surfaces create handling problems.
- Use only where the manual permits.
Why tape is unreliable
Tape compresses and shifts under repeated load.
- Adhesive can soften with heat.
- Layers can slide unexpectedly.
- Residue complicates later repairs.
- Use a rigid solution instead.
When to replace the chair
Some repairs cost more than the chair merits.
- Inspect the base for cracks.
- Check the tilt mechanism.
- Check loose frame connections.
- Replace unsafe structural parts.
Frequently Asked Questions
Will WD-40 stop chair sinking?
No. It cannot repair a failed internal seal.
Is a spacer a permanent repair?
No. It only locks the height.
Are cylinders universal?
No. Confirm size and compatibility.