So I've had this office chair for about a year now. Recently, whenever i sit down it just sinks. But when i get back up, the chair immediately rises again. Can this be fixed or is it time for a new chair?
The chair has a piston and cylinder in it and the air is leaking out of the cylinder. Mostly they are throw away, but its possible to fix. depends on the chair. If you get lucky it will be something like a bolt you can tighten up. One way to find the leak is have weight on the char, or have someone sit in it, and listen for the hissing sound from the air leaking out.
Striker and Rofle are right. Most manufacturers will not sell the parts and the ones available as a uniform fit, do not fit. Purchase a new chair. Have fun shopping.
Just get a jubilee clip or hose clamp and use it to fix the chair. Its a quick, cheap, and easy fix that always works. I made an article on wikihow with instructions and pics a few weeks ago. I posted a link in the source.
Many adjustable chairs have a thing which resembles a shock absorber in the support stem. You allow air IN or OUT to adjust the height with a manual valve. It sounds like the valve is defective and leaking, which allows the chair to sink as you say. There are NO user repairable parts, so it is time for a new one... You can TRY rapidly cycling the valve several times to see if it will seal again, but once a leaker, it is most likely always a leaker...
