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Start here--Base Removal (required to measure or remove a cylinder)
- See How to measure to replace a gas cylinder (Read below)
- How to remove and install a gas cylinder (Read below)
- How to remove and install a gas column (Read below)
First turn the chair up-side-down so that the and in the center of the base bottom underside can be seen.
Spread newspapers on floor to prevent greasy falling parts from causing stains
With a screw driver or needle nose pliers, lift up the holding clip upper portion only from the piston rod tip
Withdraw the base while pulling and turning. The base will easily remove from the gas cylinder most likely pulling with it (hidden inside) the 2 washers and ball bearing. Set these parts aside to be reinstalled with the replacement base. There should be 4 small parts. If not, look inside the withdrawn column for the remaining part(s) where usually you will find a washer at the bottom.
If you are replacing a base with new supplied column, skip down below to Column Removal---All types
Installation and bearing kit information
Measuring to replace Gas Cylinder-Not removed from Mechanism
A replacement Gas Cylinder cannot be properly measured unless the base has first been removed. Optional method
To install or replace a base, first replace the rubber cushion onto the piston rod, pushing it as far up as it will go. Then the large washer, then a lightly greased bearing and lastly, the other large washer. Wipe off greasy hands on the gas cylinder body. Now, slip the base with hub column up onto the gas cylinder. The remaining small washer and clip are then lastly installed onto the protruding piston rod end at the outside bottom of the hub column (view schematic). These six small parts can all be easily replaced using our very low cost bearing kit #108 with printed schematic.
Abacus uncommonly includes a new column (AKA standpipe) with a new replacement base. We recommend you use this new column. This is especially important if your chair has a lot of milage on it, as the plastic part inside the the steel column near the top supporting the gas cylinder may be worn or perhaps cracked, loose or broken. All of which will cause your chair to annoyingly rock and wobble while in use. To remove the column which often appears that it does not remove, read this.
Measuring to replace Gas Cylinder if Removed from Mechanism
size Gas lift Cylinder diameter is 1.102". For quick reference, it is a little over 1 1/16" and a little less than 1 1/8".
These will not fit chair manufacturers, Haworth, Vecta, Knoll, and some Steelcase whose cylinder diameter is closer to 3/4".
size will not include some Haworth, Steelcase & Herman Miller having cylinder diameters close to 3/4". These exceptions are available but only through special order.
Gas Cylinder Removal
There are 2 methods
(Click either image method)
Gas Cylinder Installation
Installing a Gas Cylinder is accomplished by simply hand inserting the Taper (releaser button) end of the Cylinder into the mechanism. Install small parts of Bearing (kit #108) per schematic
, lightly greasing the bearing. Wipe off greasy hands on the cylinder and install base. Turn the chair over into it's normal use position. Sitting on chair once or twice is enough to make the tapered joints fit unimaginably tight.
Click photo to see cylinder selection
Gas Cylinder Removal...and much more
View all Gas bases
Go back to Gas cylinders
Column Removal---All types
Virtually all columns in 5 star (leg) office chair gas bases are removable. When replacing a column in a gas office swivel base for replacement, the column diameter must be the same as the replacement. The diameter is measured midway at it's overall length (height). It will be either 1 3/4" (45mm) or 2" (50mm). No others are available.
With base and column in hand, squirt a shot or two of WD 40 at the at the topside of the Base and Column aiming where the Column and Base meet. Turn Base over and repeat at the underside of the Base and Column. The WD 40 must run down entering the tight fitting tapered joint to facilitate removal. Encourage this by sharply striking the side of the Column from 4 directions using a short length of 2" x 4" (14" to 18" will do very nicely) or a steel hammer. The idea is to "Shock" the Column setting up a vibration which will permit the WD 40 to run into the joint. Set the Base and Column aside for 5-10 minutes to permit the fluid to penetrate into the joint.
Then, with Base and Column underside facing you and using a steel hammer, strike out the protruding column with medium/hard blows. It may take several blows before it removes. Do not use a mallet! Nine out of ten columns can be removed in this manner...sooner or later. If you have a Ten, purchase a new Base with included Column.
It is highly recommended to replace the Style #108 Bearing Kit (each kit includes a schematic) whenever removing the base, column or gas cylinder. A #108 kit if ordered separately does not meet our required $20.00 minimum merchandise purchase.
The Column does not require any special installation into the Base. Simply inserting the Column into the tapered center base hole is adequate as the weight of the chair and normal sitting will seat the Column taper very tightly after only a single use or two. Do not use any tools to seat it tightly.
How to Measure a chair Gas Cylinder
How to Remove using a pipe wrench
Remove using a Lift-Off® tool