Question

Why does my office chair always sink down when I sit down on it?

I have an office chair with a cylinder on it that raises it up and down but lately when I sit down on the chair it immediately sinks down but then holds up fine after I raise it back up and just sit there.

But then after about 30 minutes of sitting down it sinks a bit again.

Answer 1

On an office chair that has an air cylinder there's an air valve that the lever attaches too and when you press the lever it opens a valve letting air out causing the chair to lower down when you sit on it and then it allows the air in when you're not sitting on the chair when opening the valve with the lever when not sitting on it which allows the chair to raise.

The valve has gone bad on the chairs cylinder and the only real fix for the chair is to replace the cylinder or replace the whole chair.

If you don't want to raise and lower the chair then you can add a hose clamp to the cylinder to keep it from lowering on you.

My office chair starts sinking after around 7 years of use which is about enough time for the chair to be replaced with a new more comfortable one anyway.