I have a sinking feeling you know that feeling that something is wrong something like the lift cylinder on my office chair.
This chair is over 20 years old and has given me good service about three years ago it started sinking.
So I used a little hydraulic jack oil to repair the cylinder that worked fine. Now it’s time to do it again but this will be different.
I know that I could buy a replacement cylinder but what’s the fun in that so why don’t you join me as I repair my pneumatic lift cylinder.
A chair could sink in 2 ways and the solution would be different too.
- If You Notice these things with your chair
- Does not support your weight at all just immediately drop to the bottom position when you sit on it
- & the pull-down / up lever does nothing, just stay at the bottom.
- Don’t feel any pressure anymore. It means all of the compressed gas is released.
- Holds your weight initially but then gradually sinks down after some time. Often this is because the seal lubricant has been rubbed away or has dried out.
If the chair does not support your weight at all just immediately drops to the bottom position when you sit on the chair you have to replace the cylinder or try some conduit or PVC pipe to slide over the rod to hold the chair up. However, if the chair holds your weight initially but then slowly sinks then you might be able to repair the cylinder by applying lubricant oil.
Why does my office chair sink
The pressure of the gas in the cylinder is critical if the pressure is too low the chair will not support your weight at all. It will just immediately drop to the bottom position when you sit on it. The gas can leak out through the support shaft seals or the valve outer seal. If this happens you have no choice but to replace the cylinder.
However, if the chair holds your weight initially but then slowly sinks then you might be able to repair the cylinder. There are only two places for gas to leak to cause this symptom.
- The valve inner seal
- and the piston seal
Often this is because the seal lubricant has been rubbed away or has dried out.
I’ve had some luck in restoring the operation of lift cylinders that slowly sink. I use a little hydraulic jack oil to lubricate the support shaft and the valve mechanism.
What to do if the chair immediately drops to the bottom position won’t stay up?
If your gas cylinder of chair loses all gas and pull down / up lever does nothing, just stay at the bottom and don’t feel any pressure anymore it means all of the compressed gas is released.
If the gas pressure is released, the cylinder needs to either be replaced or disabled by using a Diy method like PVC pipe, no more adjustment but you has fixed the sinking problem forever.
- Your only choice is to replace the cylinder.
- If you don’t want to spend money to buy a cylinder, You could use some easy DIY techniques to stop the chair from going down. For example: Cut some conduit or PVC pipe to slide over the rod to hold the chair up.
Before talking about the replacement cylinder I want to share with you simple DIY methods that don’t as expensive as buying a replacement. However, remember it will come with a cost that you can’t adjust your chair height.
How to fix an office chair that won’t stay up
Before you try any of those DIY methods you have to Set the chair to the preferred height. You will not be able to adjust the height after this repair, so make sure you have it right. The seat of the chair should be level with your knees when you are standing.
Method 1: Empty Toilet Paper Rolls Cardboard – When Empty toilet paper rolls are saviors.
I can’t believe this actually worked. So unbelievably simple and unique tips. No cost at all and long-lasting result.
What you will need:
|1. Four empty toilet paper rolls|
|3. Duck tape|
- Take 4 empty toilet paper rolls cardboard as substitutes for the pipe/tube. Cardboard number depends on you weight if you overweight you may need 5-8 pieces.
- Cut the empty toilet paper rolls apart lengthwise from top to bottom with scissors.
- And tape it around the metal part of the chair! This will must work:)
Method 2: Using a Hose Clamp & Duck Tape
What you need in this DIY method is a $1 hose clamp and 2 minutes of your time.
- Set preferred height: First set your preferred height of the chair you wish to have.
- Clean the cylinder: Clean grease lubricant from the cylinder first.
- Wrap with duck tape ( Optional): Wrapped some duck tape first around the spot (a couple thick is enough ). So the hose clamp has a better grip. It would make it more powerful and last longer.
- Fit the hose clam: Fit the metal hose clam over the hydraulic shaft.
- Make sure you put the clamp at the bottom end of the hydraulic shaft, not the top.
- Tight hose clam: Tightened it with a screwdriver as much as you can.
- You can use a 2-3 Hose Clamp to make it more last longer.
Why hose clamps method is better than other:
- Hose clamps because they are widely available and cheap.
- It’s not necessary to dismantle the gas cylinder from the chair.
- Don’t require buying a wrench!
- It is quite hard to get a short piece of PVC pipe, they only have wholesale shops where you can buy full-lengths.
Method 3: Pneumatic Chair fix with Duck Tape
If you’re looking for a temporary but immediate solution that wouldn’t necessarily require going to a store then you can follow this trick.
What you need some duck tape, rubbing alcohol, a paper towel.
- Just apply to rub alcohol to the shiny part & use a paper towel to remove the grease.
- Don’t have Rub alcohol follow the step below.
- Slice open the cardboard from within toilet paper rolls.
- Tightly tape several layers of it around the metal bar.
- I guess alternatively some small stack of paper would do the trick as well.
- Use a paper towel or a piece of cloth to remove dirt or grease from the cylinder.
- Take Duck Tape and and wrap it around on the shaft.
- Make sure that you wrap it very thick to simulate a thick pipe.
For long-term results:
- Use a Hose clamp with the duck tape.
Cons of this method:
- The duck tape held up well but obviously doesn’t work in every situation.
- Temporary fix: works for a few months.
In reality, of course, more a temporary fix, my primary point is what could you do with what you had in the house without spending any money, so use duck tape. If a hose clamp added then this is better than other cheap solution which includes fitting pipe.
Method 4: Using PVC Pipe
If you have a chair that won’t stay up anymore you have a few options to fix it and definitely, the PVC pipe DIY method is the best DIY method for the long results than other methods. If you always maintain the same height level or rarely ever set my chair at a different height,, you can permanently fix your cylinder at next to no cost।
Note: If you don’t have any tools to cut the PVC or ABC, Don’t worry I will show you an easy trick using a rope to cut the PVC without tools.
Don’t want to disassemble your chair but still want to use the PVC technique then follow this easy method:
- PVC cut lengthwise for the height you need.
- Piece of PVC split horizontally and you don’t have to even take anything apart!
- Wrap around the cylinder and secure with a zip tie, hose clam or wrap with duck tape if needed.
Mehod 5: Another PVC Method
Step 1: Adjust the cylinder at the desired height where you like it:
the first step to fixing your chair is to go ahead and sit in it. Adjust the cylinder at the desired height where you like it.
Step 2: Measure and cut the PVC pipe to the desired length:
Then get up we need to measure that now. You want to measure where the PVC pipe is gonna stop. it’s gonna stop on the seat and on the wheelbase. So you want to take the measurement from the wheelbase to the seat.
Step 4: Cuting the PVC pipe
According to your measurements, you’ll cut the PVC pipe according to how long how high you want your chair so the chair will be full up all.
- Just mark this pipe with a sharpie and cut it with a hacksaw.
- Here’s a little trick for getting a straight line on a piece of pipe get a square piece of paper join the ends of the line then just take your sharpie and go around the pipe and it will be a good reference if you use a hacksaw to cut this.
Step 5: Remove the retaining clip at the bottom of the cylinder:
- Next Turn your chair over and you can see the bottom of the wheelbase. There you will see an end clip.
- Just pry up the spring-loaded locking tab and slide it off. Be careful there are some washers you should keep for later.
- When it removed the wheels and base can be lifted off and set aside.
Step 6: Place the PVC tube in the cylinder
So You have Your PVC tube. Now You are just gonna put it down to the cylinder.
Step 7: Assmble the chair
And the end makes sure you put your washers back in order the way they were when they came off and then you’re gonna put this top bar wheelbase back washer and then that retaining clip at the bottom of the cylinder and there we go.
How to fix a chair that slowly sinks?
If the chair holds your weight initially but then slowly sinks then you might be able to repair the cylinder.
I’ve had some luck in restoring the operation of lift cylinders that slowly sink. I use a little hydraulic jack oil to lubricate the support shaft and the valve mechanism. I don’t know if it’s the hydraulic jack oil or that I turned the chair upside down and cycled the cylinder but it worked anyway.
Method 1: Cheap thick ball bearing grease to lubricate
- Remove the base of the chair. Turn your chair over and remove the retaining clip at the bottom of the cylinder and slide out the chair base with wheels.
- Now use some grease on the shaft or you can use hydraulic jack oil too.
- After that Put back all washers and the base with wheels and lock retaining clip at the bottom.
- Now after assembled the chair you should seat 2-3 times, don’t worry it will sink in at first then it will not sink any more.
Note: In some cases, It will only work for a few days or months. So if you want a long solution should follow method 2 but it is a little bit difficult and complicated too. So if method 1 works for you ok that’s great.
Method 2: Lubricate Inside of the Piston.
The last time I fixed this cylinder I did it without removing the cylinder from the chair mechanism ( method 1 but using jack oil, not WD-40 ) it was kind of awkward but works. however today I’m removing the cylinder so I can show you exactly what I did.
I removed the clip and washer at the bottom of the chair base and slid off the base and the outer cover all that was left was to remove the cylinder from the tapered hole in the seat.
Remove the cylinder. To remove the cylinder from the seat mechanism you can use a pipe wrench if you have one. I would recommend a 14″ pipe wrench or the bigger the better but if you have 10″ it may work.
- Using your pipe wrench tighten it on your cylinder as close to the seat mechanism as possible.
- Now turn the pipe wrench a quarter turn until it comes loose.
- Loosen it until you can pull the cylinder off.
- It’s not as easy as it looks it takes a lot more effort.
I supported the cylinder in a button-up orientation.
- Then I made an aluminum foil cofferdam around the button end of the cylinder and added about a tablespoon of hydraulic jack oil.
- when I pressed the button with a screwdriver the piston extended and a little oil lubricated the valve.
- I repeated the process again on the button end before I turned my attention to the rod end.
Now I clamped the cylinder so the button was compressed by the bottom of the vise and the operating rob was on top.
- I added an aluminum foil dam and about a teaspoon of oil.
- then I compress the cylinder several times working the oil into the bottom of the cylinder.
All that was left was to reassemble the chair.
- Now assemble the cylinder in the base.
- Put washers at the bottom of the chair cylinder back in order the way they were when they came off
- and then you’re gonna put this top bar wheelbase back washer
- and then that retaining clip at the bottom of the cylinder and there we go.
- The next part is putting the chair top onto the chair base
- So grab your chair top.
- and line the hole with the cylinder and place it on top.
- Now sit on the chair, and the cylinder will be stuck again with the chair.
Why you should not use WD-40
I saw lots of blogs and youtube videos where they are suggesting using wd-40 to lubricant the chair shaft to stop the office chair from sinking.
It’s a big no-no.
Don’t use Wd 40 on the shaft of the chair. But Why…?
Most Importantly WD-40 gets a chemical reaction with plastics and rubbers.
Office chairs that have an O-ring rubber seal on the shaft to prevent them from leaking air. Now if you use it on the shaft, It will make a chemical reaction with this O-ring rubber seal and break down the seal that is in the cylinder. If it breaks it gonna leak air and your chair will fall to the ground.
It might help you to stop the chair from sinking but in long run, it will damage your chair. WD-40 isn’t really a good lubricant and wont last, rather use it to clean up all the gunk than apply a silicone type of lubricant.