Office Chair Backrest Repair

Repairing an office chair backrest requires selecting the appropriate method based on the specific issue. Here are common problems and their solutions:

Repairing the Gliding Backrest of the Sihoo C500 Second Generation Deluxe
If the backrest bone block is loose and fails to stay in place, the back cover needs to be removed for tightening. First, pry open the back cover from the bottom edge, use a screwdriver to remove the five internal fixing screws, and take out the aluminum alloy cup holder. Check for wear or gaps at the bone block connection. If long-term use has caused component deformation, replace the corresponding parts; if only the screws are loose, ensure they are tightened until the cup holder and bone block are fully flush to prevent further sliding.

Repairing a Detached Seat Backrest Cushion
Cushion detachment usually occurs due to a fallen nut at the bottom of the seat or damage to the fixing structure. During repair, first use a hole opener to enlarge the hole at the detachment location to an appropriate size. After cleaning out any remaining nut fragments, screw in a No. 6 metal wire post as a new fixing point. Insert a four-toothed zip tie into the wire post's tooth slot, adjust the zip tie's position to control the nut height, and trim off any excess zip tie before inserting the nut into the hole, ensuring it is flush with the seat surface. When the glue is nearly dry, unscrew the wire post, pour specialized glue into the hole to expel air, and repeatedly twist the wire post with a screwdriver before the glue fully cures to prevent adhesion that could make future disassembly difficult.

Repairing an Office Chair Backrest That Fails to Rebound
If the backrest fails to rebound, first check if the adjustment lever is stuck or damaged. If the lever rotates smoothly, inspect the nut structure at the bottom of the chair: some chairs control backrest tension with a nut. If the nut is loose or the threads are worn, the spring may not reset properly. In this case, use a wrench to tighten the nut or replace it with a matching new one; if the spring is aged or broken, disassemble the base to replace it with a spring of the same specification.

Repairing an Office Chair Backrest That Fails to Stay Upright
Hydraulic system failure is a common cause. Lay the chair on its side to inspect the transmission components. If the pivot fixing screw is a non-standard 10*1 size, replace it with a standard No. 10 screw: first, use a tap to rethread the original screw hole or directly screw in the new screw with a wrench (be careful to avoid stripping the threads). When installing a 30mm-long screw, if forcing it in causes excessive clearance, add a nut to the bolt as a temporary fix and adjust the screw's position by adding or removing washers to ensure it does not obstruct the hydraulic rod's range of motion. After repair, repeatedly test the backrest's upright function to confirm there is no jamming or tilting.