How To Fix A Sinking Office Chair

You’re probably here because you happily sat on your new office chair, and it just straight up sank? Or maybe, your office chair is becoming old and keeps on sinking every time? We know and feel the troubles you’re going through, and we are here for you to make it go away!

Why Do Office Chairs Sink

Office chairs that have adjustable height features can be classified into two types, based on the method their cylinder works with: Pneumatic and Hydraulic.

Hydraulic office chairs consist of a section of highly-compressed liquid and another section of compressed gas. Adjusting the lever changes the fluid pressure, and in turn, the height of the chair.

Pneumatic office chairs store compressed nitrogen gas inside the cylinder. The movement of the lever changes the pressure of the gas, which leads to vertical movements of the chair.

Office chairs sink because of a faulty cylinder. Overuse of the lever or poorly manufactured cylinder and piston can damage the seal and cause unwanted leaks. This leads to an imbalance in the pressure system of the cylinder and your office chair starts sinking.

As you might’ve figured out already, sinking mainly happens on chairs that operate with the pneumatic system. But, since hydraulic systems also come with compressed gas, slight sinking also takes place in the long run.

Whichever system your chair may operate with, sinking isn’t an unsolvable problem. There are several ways in which you can restore your office chair’s height-adjusting capabilities and sit comfortably.

Different Ways Of Fixing A Sinking Office Chair

Using A Hose Clamp/Jubilee Clip

What You Will Need:

  • ¾” hose clamp or Jubilee Clip
  • Strong Duct Tape
  • Screwdriver (optional)


  • Take off the plastic tube that covers the cylinder and clean the cylinder properly. For most chairs, you can just slide it off. You might need to unscrew the wheels and base to take it off for others though.
  • Adjust the height of the chair exactly how you need it, as this height will be irreversible.
  • Unscrew the Jubilee Clip and put it around the cylinder of your chair at the height you need, but don’t tighten the screw.
  • Cover the cylinder with two or three layers of duct tape below the clamp, which fixes it at its position and doesn’t let it slip.
  • Make sure your chair is at the right height and tighten the screw of your Jubilee Clip.
  • Exert low pressure on your chair to check if the clamp works. After that, for the final check, sit on the chair and it shouldn’t sink anymore!

Using a PVC Pipe or Plastic Spacers

What You Will Need:

  • A certain diameter of PVC Pipe or Plastic Spacers
  • A Ruler
  • Hacksaw OR Screwdriver
  • Protective Facemasks


  • Similar to the previous method, take off the plastic skirt or tube protecting the cylinder.
  • Using the ruler, measure the diameter, or the horizontal length of your cylinder.
  • Adjust your chair to your required height and measure the length using the ruler too.
  • Purchase a PVC pipe or strong plastic spacers with the exact diameter of your cylinder or a bit larger. You can cut the PVC pipe to the length of the cylinder by yourself later.

You can then continue the process in two separate ways.

1. If you’re good with cutting machines like hacksaws:

  • Use a hacksaw to very carefully slit your PVC pipe on one side along its length. You must wear protective face masks and gloves to prevent harmful chemicals from entering your nose and mouth.
  • You can then reattach the plastic tube back over the pipe.
  • After that, you should create multiple loops of zip ties to tightly hold the pipe in place, or apply pressure on the slit side so that the pipe snaps around the chamber.

2. If you don’t prefer cutting machines or you’re using plastic spacers:

  • You can use a screwdriver to simply remove the wheels and base of your office chair.
  • Fit the PVC pipe or the spacers around your cylinder, which is at your desired height. The spacers work like the Jubilee Clip, but greater in number.
  • Put the plastic covering of the cylinder back on.
  • Reattach the base and wheels of the chair.

After employing either method, you can gently exert pressure on the chair.

  • Lastly, you can sit on the chair for the final assurance that your chair has stopped sinking.

You can carry out the same method using Polypropylene (PP) water pipes readily available in homes as well.


Sinking can take place due to friction taking place for prolonged periods and smoothening the movement may solve the problem.

You can apply lubricating oils on the joints of the cylinder with the chair parts to make movements swifter.

Getting A New Pneumatic Cylinder

All the methods mentioned above will stop your office chair from sinking but may not be a permanent solution. You can’t adjust the height of your chair either.

Getting a brand new pneumatic cylinder and replacing the old, weary one can solve all your problems. It may come at a price but it’s worth it in the long run.

It’s recommended to get your cylinder replaced by professionals as removing the old one and attaching the new one can be a tricky and tiresome task. But, in case you know your way with tools, we’ve described the process below.

What You Will Need:

  • A strong Allen Pipe Wrench
  • A Rubber Mallet or Hammer


  • Ensure the place you’re carrying out the task is flat and clean.
  • Secure the Allen Pipe Wrench in the meeting position of the office chair mechanism and the cylinder.
  • Twist the wrench lightly with mild pressure until the base and cylinder separate from the rest of the chair. Apply some lubricating oil on the mechanism if the cylinder doesn’t come off quickly.
  • To separate the base and cylinder, first, turn it upside down. You can follow two methods after that:
  1. Using a hammer or rubber mallet, hit on the protruding part of the base, and this will easily disconnect them.
  2. If you don’t see a protruding part, manage a 2”x4” sturdy wood block.

Hold the block over the base and cylinder junction and hit it with a mallet or a hammer, until they separate.

  • Now hold the base straight on a flat surface and fit the new cylinder into the base. You shouldn’t face any troubles as long as the cylinders are of the same type.
  • Ensuring they fit together, attach the assembly to the office chair mechanism while holding the body of the chair upright. With a little push, the cylinder and mechanism will connect easily.

And, there you have your old office chair with a new cylinder and no traces of sinking!


A sinking office chair can completely beat the purpose of height-adjustable chairs. It can also be quite uncomfortable to sit on as well as causing health issues. Using the simple methods described above, you can quite easily eliminate this sinking problem of your office chair and continue working conveniently.

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