Home Improvement → Re: Hydraulic Chair Doesn't Stay in Place

If it's a name brand chair, like Herman Miller or Steelcase, then yes, you can buy replacement parts. If it's a $99 special from Office Max then no, it's a disposable Chinese item.

It's a Bodybilt. Not the $99 variety for sure.
How can I be sure it's the cylinder and not something else?

Oh, those are good chairs!

The hydraulic cylinder's job is to hold it's vertical position, your doesn't so it has an internal leak. Not sure where you'd buy replacement parts but they should be available. You may find an equivalent part here: »www.echairparts.com/serv ··· tegories

It is the only part on the chair responsible for the chair height. Yours is either leaking internally (bypass on the cylinder walls) or the valve doesn't close properly. The valve is integrated into the cylinder assembly and it would be dangerous to attempt taking the assembly apart.

About the only other possibility that you can check is whether the handle on the chair for the up - down motion is traveling freely and that it doesn't somehow continue to put pressure on the valve (bend handle / mechanics, dirt or foreign objects between handle and valve) causing the valve into a partially open state.

Whatever you do, do it carefully without applying strong forces to the hydraulic cylinder (many are pressurized). Those chair lift mechanisms have been known to cause injury and even death!