DOZYANT 6" Long Stroke Office Chair Gas Lift Cylinder Replacement,Hydraulic Pneumatic Shock Piston Heavy Duty (450 lbs) for Tall Person Universal Size Fits Most Executive Chairs, Highest End Class 4

I have some very expensive office chairs, and the cylinder went bad on them. I did not want to spend several hundred dollars for a new chair and was researching replacement of the cylinder online, when I came across this excellent value and easy to replace cylinder for my chairs. Now my chairs function just like as if they were new and give all the proper support. These heavy duty cylinders work excellent because I’m a pretty big guy weighing about 300 pounds and they support my weight all day.

My B009ZNEUOA HON Lota Mid-Back Work Chair from 2012 started sinking this year. By August the cylinder would no longer hold any height. Rest of the chair had been holding up for seven years through multiple moves so I wasn’t about to replace it all. I put up with the low seating until my neck and my hands started to complain. Okay, okay—time to swap out the cylinder instead of a whole new chair. The cylinder is packed in a plain brown box with no instructions or anything. It is mislabeled for the five-inch model but the Amazon customer questions show that this is indeed the six-inch job. That’s it—pull it out of the box and you only have everything else to do. Installing the new cylinder was easy. Only tricky part about that was lining the seat up with the post so the base plate would slip right over—took about a minute. It was getting the old cylinder out that took me more than an hour, if you count the trip into town for a wrench. Right away you will need the right tools for the job: 1. Pipe wrench with at least 14-inch handle. 2. Two or more clamps. 3. A work table or similarly study clamping station. 4. B000F09CF4 Kroil, the oil that creeps! 5. A good metal hammer. The basic process is to pop the clip off the bottom of the old cylinder. This will allow the wheelbase and the bottom casing of the cylinder to separate from the rest of the chair. Some washers fell out of the bottom and the piston stuck out of the cylinder itself. Next, I had to remove the tilting base plate from the bottom of the seat. I had to do this after spending ten minutes trying to wrench the damn cylinder loose and only making gashes in the metal. For my Lota chair, I undid four hex bolts with a 3/16 hex wrench and pulled the plate clean off. Easy peasy. Then I added into the socket of the base plate some Kroil, the oil that creeps! Boy was that stuff slippery. The socket and cylinder were so tight I am not even sure the Kroil crept in there much. After that I clamped the plate down to a work table with a pair of strong C-clamps. It took a few minutes of adjustment to get them in place enough to keep the plate from twisting off the edge of the table. From there I ran into town and bought a 14-inch pipe wrench from Lowe’s. An extra 14 bucks. I recommend getting an even longer one for the leverage. Once clamped on, the wrench will slide one direction and dig in when pulled the other way. Pull with both hands, with all your might, in the biting direction. Just when you think that sucker isn’t going to come loose, be pleasantly relieved when the cylinder twists right out in one motion. At last, you’ll need to clamp your wheel base down and tap out the old cylinder bottom. In my case, the bottom was flush with the barrel of the base, so I couldn’t use a wide-face mallet, while my small rubber mallet was just too darn light. Finally, I took a good old fashioned steel hammer and with careful aim knocked it out in about six hard whacks. The finishing touch, before reassembling the whole chair with the new cylinder, was to add swap the original casters for rollerblade-style B01CTIG4GE Heavy Duty Caster Wheels from Office Oasis, an office aftermarket supplier. They came five to a pack and roll more smoothly and swiftly than the OEM wheels. For final assembly, the new cylinder dropped into the wheel base nice as you please. Don’t forget to pull the purple safety cap off the top! This exposes the plunger that the chair base plate will tap whenever you pull the lever. Day one at least, my chair works immediately well with the new cylinder. Without sitting on the seat, I depressed the lever and let the chair raise to its full height. Now I sat down and adjusted down so my feet were just touching. This put my hands and my head at a more ergo-friendly posture. Overall I think it is a good idea, when you are replacing the cylinder, to go head and consider upgrading the casters, possibly even the whole wheelbase. Maybe get some coverings for the stems of the base as well to protect them from being marred by your shows and to help you lift off.

Worked as expected. Replacement of the old one was easy and this fit as advertised.

Short and sweet: So far, so good, but be sure to remove the purple cap at the top of the cylinder before installing. If you don't you will have a hard time getting the lift mechanism of your chair to operate the cylinder. I installed the cylinder after a day of trying to remove the old one (WD-40, pipe wrenches, grip cloves, and a rubber mallet are your friends). After installing the new one I quickly realized the lift didn't work: The lever that controls the cylinder was coming to a hard stop. There are no instructions included in the package, so I had no clue there is a protective purple cap the prevents the button that releases the gas from being pressed while in transit. I didn't realize it until I removed the whole lift assembly from my chair and took a flathead screwdriver and mallet to it to see if I could press the button manually. The purple cap fell out while attempting to press the button with the screwdriver. Now that everything is in it's proper place, the lift works fine. Supports my 255 lbs easily and is VERY tall. I added some 4" nylon wheels to assist rolling on thick pile carpet, so my chair now sits almost as high as a barstool. I love it!

Works perfect and my office chair no longer goes down throughout the day.

Finally - a chair lift that goes tall enough! I'm 6'1" and about 275 lbs. The original lift on the chair (chair from a big box office store years ago) and one subsequent replacement didn't go high enough. I've been left sitting with legs crossed under the table for years. :( Table is high enough, chair isn't. Well this one will even go *higher than the table*! It says 1" more than usual (6 vs 5 inches), but due to the mount (vs the old lift cylinder) I'm getting closer to 2". Love it!! This one can still go down lower, too, as usual. Haha BUT to get the old lift cylinder out of the chair, it may not be pretty, and here are some tips. FIRST - ESSENTIAL: flip the chair over and spray around 360 degrees where the cylinder goes in (on both ends) with *penetrating oil*, like "PB Blaster" (which rocks BTW - WD40 is NOT penetrating oil - everyone should have a can of PB Blaster on hand), tap the joint to set up vibrations, then let it sit 30 minutes to penetrate. THEN, do it at least one more time. Spray, tap, wait. THEN for the bottom, where the cyclinder goes into the wheels, most effective to whack the bottom of the cylinder with a large rubber mallet. If the bottom of your existing doesn't extend past the bottom of the wheel assembly, try using the mallet on the wheel assembly, or use a large wood dowel to tap on the metal *edge* of the cylinder (not the middle, where the clip is). Also try spraying one more time and letting it sit overnight. Then for the top, where the hydraulic rod goes into the chair, it can be more of a battle if rusted on, as was my case. Use a BIG pipe wrench on the hydraulic rod (which will ruin it by leaving wrench marks on the smooth rod surface, so you need to decide up front that chair is a loss anyway, due to the dead cylinder, so if you can't get the old cylinder out you are replacing the chair anyway. Whack the pipe wrench handle HARD with the mallet, or even a metal "engineers hammer" (mini sledge). In my case that broke the end of the old hydraulic rod loose from the rust after the 3rd hit and out it came. Note that hitting the body of the hydaulic cyclinder to try getting the hydraulic rod out of the chair is likely a really bad idea. Likely pressurized with a big spring in there - don't do it, imho. Wipe the penetrating oil off the holes in the wheel assemply and chair. Even better, use some soapy water on a towel to clean the oil off and dry it. Then drop your new hydraulic cylinder in and away it goes!

Good quality and was easy to install in the chair.

DO NOT BUY THIS. I ordered the 6-inch option. When it arrived and I installed it, it was somehow TALLER than the 8-inch cylinder I replaced. That alone should tell you how little quality control exists here. I’ve gone through several cheap gas cylinders before, and this is by far the worst one I’ve ever dealt with. When I tried to remove it to return it, it turned into a nightmare. A pipe wrench wasn’t enough. The metal scraped and gouged the inside of my chair’s collar, then mushroomed outward, which made it wedge itself even tighter. At that point, removal was borderline impossible. It got so bad that both myself and another grown man were slightly injured just trying to get this thing out. A chair cylinder should never become a safety hazard. TL;DR: Don’t buy this junk. There are plenty of other cylinders that cost the same and don’t turn your chair into collateral damage.