One of the defining features of an ergonomic chair is its adjustable parts. People pay good money — sometimes more than a thousand dollars — for a seat they can maneuver into something that fits their build perfectly.
One of these features is an office chair’s adjustable height — whether you’re taller than six feet or remarkably petite, there’s always a way to find a setting that’s just right for you. You don’t have to strain your back or legs, which happens if you use an office chair that’s either too high or too low.
After some time, however, the seat begins sinking on its own. It’s a common occurrence, and there are several quick fixes to get it back to the height you prefer. These solutions don’t need a professional, which means you can do it yourself!
We’ll also share a more permanent solution, which you can still do on your own. It may look complex, the steps we’ve outlined can help you out.
Are you ready to face the sinking chair challenge head-on? So are we!
Let’s start!
Table of Contents
What Causes Your Office Chair to Sink?
One of the most frustrating things you can deal with is having an ergonomic office chair that looks like it’s in pristine condition, except that it won’t stay at the height you want. Added to the stress is the possibility of developing health challenges — you may start feeling the tension in your neck. It’s the part of your body that you’ll use to compensate for the lack of height.
Remaining healthy is crucial these days. So if you start noticing that your office chair’s sinking, you shouldn’t waste any time trying to resolve it.
Your office chair has mechanisms that allow it to change seating positions without hassle. These use hydraulics that is controlled by a lever right underneath the seat.
Hydraulics uses hard-to-compress liquid metal, like oil, to make machinery move. Pneumatics works the same way, except it uses easily compressible gas.
Office chairs, being lighter, usually work using pneumatics. When you push down on the lever underneath your chair, it pushes gas in and out of the chamber. It’s what allows your seat to go up and down.
Wear and tear of your height adjustment mechanism roots from frequent use over a long period. It means the chair cylinder — the part of your chair that connects the base to the seat — isn’t working.
Inside the cylinder is nitrogen gas. Sometimes, after years of constant use, it leaks. When this happens, the lift mechanism ceases to work, causing your seat to sink.
How to Fix Your Sinking Seat?
Now that we’ve determined where the main problem is, the next question is, what do you do about it? There are several quick fixes you can do — none of which require the services of a professional.
Quick Fix 1: Using a Hose Clamp
This method keeps your chair at your preferred height and won’t require you to disassemble it. All you need is a hose clamp (sometimes called a Jubilee Clip). Here’s how to do it:
Put the chair at your preferred height.
Before you begin, make sure your chair is at the height you want. Usually, you adjust it using its pneumatic lever. However, this is no longer an option since sitting on it will make it sink.
As an alternative, you can get your chair to the appropriate height by standing next to it and use your knees as a reference. Ideally, the seat should be level with them.
Expose the gas cylinder.
You’re going to work on the gas cylinder of your chair. It’s the bar that connects the seat to the base.
Some office chairs have a plastic housing covering the cylinder — remove it so you can access the bar directly.
Attach the hose clamp.
Loosen the screw of your hose clamp and open it. Wrap it around the cylinder, but don’t tighten it yet.
As an extra precaution, you can wrap the cylinder with rubber or duct tape. You’ll need the hose clamp to grip the cylinder tightly; so the seat doesn’t slide down.
Secure the hose clamp.
When you’re sure the chair’s at the correct height, slide the clamp to the top of the cylinder. Pull the clamp and turn the screw to tighten it.
Test your handiwork.
Don’t assume that your chair’s fixed. Sit on it to see if it holds. Check If the height is where you want it to be. If it isn’t, you can unscrew and reposition it.
Quick Fix 2: Use a PVC Pipe or a Plastic Spacer
Another way to do it is to use a PVC pipe. The process begins similarly to the first fix.
Put the chair at your preferred height.
We’ll start by ensuring you have your chair at your preferred height. Don’t sit down on it — otherwise, it’ll sink.
The best workaround for this is to stand next to your chair. Make sure the seat and your knees are aligned.
Expose and measure your gas cylinder.
Our next step is to expose your gas cylinder, which is the bar that connects your chair’s base to the seat. For some models, plastic housing covers the cylinder. You can easily take this off, allowing you to access the bar directly.
You need to measure the cylinder to make sure your PVC pipe can fit. Hold a ruler up horizontally against it. It gives you the cylinder’s diameter.
Compare the measurement to the PVC pipe’s diameter. If you find the pipe is narrower, you may have to buy a new one.
Next, you have to get the height of the pipe. You’ll need to measure the wheelbase to the seat. You’ll have an easier time using a tape measure since it’s more flexible than a ruler.
Cut the PVC pipe.
Use the measurements from the previous step to resize your PVC pipe. You don’t need to meet the exact measurements but get it as near as possible.
You’ll have to cut the PVC at least twice. The first gets the pipe to the correct height. The second provides an opening that will allow you to attach it to the cylinder. This cut goes lengthwise (down the middle).
Don’t forget to wear a mask when you’re cutting the pipe. It will prevent you from inhaling the pipe’s particles.
Attach the PVC pipe to the cylinder.
Hold the lengthwise cut of the pipe against the gas cylinder and press down. It should cause it to snap into place.
If you’re having difficulty with this step, you can cut the PVC pipe into smaller pieces and snap these in bits. The pipe should cover the length of the cylinder when done.
Test the chair.
Sit down on your chair and check the height. If you want it a bit higher, you can snap on an additional pipe piece. Repeat the process until you’re satisfied.
Both of these methods can work, but they are considered temporary. They also come with several drawbacks.
Neither option allows for height adjustment anymore, which takes away the essence of having an ergonomic office chair. It’s also more likely for the plastic pieces of your chair to crack or break, causing more damage.
If you want a more permanent solution, it’s best to focus on the gas cylinder itself. If you can get that working, you’ll be able to fix the sinking seat problem.
Can you Regas Your Office Chair?
Your chair’s sinking because the gas inside the cylinder has leaked out. You may ask, can you regas an office chair?
The short answer, however, is no. You cannot refill the gas cylinder of your office chair. It doesn’t mean that the only option left to you is buying a new one.
If your office chair is relatively new or generally still in good condition, you can opt to replace the gas cylinder instead. This method is cost-efficient and will prevent your seat from sinking.
How to fix your office chair’s hydraulics?
You can replace your chair’s gas cylinder on your own. You need to set aside time and make sure you have your tools with you.
Here’s what you can do.
Make sure you have everything you need.
Before you start, prepare everything. It helps you keep organized and will help you move from one step to the next smoothly.
Make sure you have the correct gas cylinder as a replacement. You can use your owner’s manual for reference when you buy it. You’ll also need a pipe wrench, a rubber mallet, and some lubricant (WD40 will do).
Prepare your office chair.
Since the gas cylinder extends from the base to the seat, lay it on its side. It allows you to access the different parts of the chair and gives you more room to maneuver as you’re replacing the gas cylinder.
Separate the base from the cylinder.
When you have your chair on its side, you can see the end of the gas cylinder from the base’s bottom. Hit the end of the cylinder with the rubber mallet to dislodge it. After doing this, you should be able to remove it.
Detach the gas cylinder.
A plastic housing usually covers your chair’s lift mechanism. Move it to the end so that you expose the part closest to the seat of the chair.
Grip the gas cylinder using a pipe wrench. Give it a couple of turns, and it should come right off. Set it aside — you can dispose of it later.
Put in the replacement cylinder.
Take the new cylinder and put it where you removed the original one.
Reassemble your office chair.
Pop on the base and turn the chair upright. Sit down on it — it will lock all the parts in place.
You only need to apply pressure to secure the gas cylinder between the base and the seat — it doesn’t use any screws.
Sit on your chair and test it out.
Try adjusting the height of the chair and stay seated for a couple of minutes. It should be able to withstand the weight without sinking.
The Wrap Up
Having a sinking seat can be frustrating, and most people think their only option is to replace the entire chair. Now you know it isn’t the case!
There are several ways to address this situation, but the most long-term solution is to replace the lift mechanism of your office chair.
The thought of having to replace a gas cylinder on your own can be daunting. You can choose to let a professional do it, but attempting it yourself is a cost-effective way of resolving the problem.
So if you’re brave enough to try, go for it!
My name is Vance, and I am the owner of To Ergonomics. Our mission is to improve your workflow by helping you create a supportive and welcoming environment. We hope that you’ll find what you’re looking for while you’re here.