Old-Style Office Chair Repair

The repair of old-style office chairs requires targeted handling based on the type of damage. Common problems and their solutions are as follows:

1. Hydraulic System Failure (Backrest Unable to Stay Upright or Adjust)

If the hydraulic mechanism fails due to issues with the drive components, first check whether the toggle is functioning properly. If the toggle is normal but the hydraulic rod is loose or has fallen off, it is usually caused by damaged or incorrectly sized fixing screws. In this case, replace them with standard No. 10 screws (30 mm in length) and secure them with nuts. When installing, ensure that the screws do not obstruct the movement range of the hydraulic rod. If there is interference, adjust the gap by adding a washer between the screw and the hydraulic rod.

2. Chair Sinking Problem

1. Hose Clamp Fixing Method
   After adjusting the chair to the desired height, slide the plastic skirt to the bottom of the cylinder to expose the adjustment cylinder. Wrap a hose clamp (or metal hose clamp) around the surface of the cylinder to increase friction in the following ways:

• Wrap rubber bands or tape to increase surface roughness;
• Lightly sand the metal surface of the cylinder with sandpaper;
• Tighten the hose clamp and test the height stability of the chair. If it still sinks, repeat the adjustment of the clamping position.

2. PVC Pipe Fixing Method
   Measure the diameter and length of the cylinder and select a PVC pipe with an inner diameter slightly smaller than the cylinder (ensure a tight fit when inserted). Saw a slit lengthwise along the PVC pipe so that it can wrap around the cylinder and return to a closed state. After inserting it onto the cylinder, secure the ends of the PVC pipe with tape or cable ties to prevent sliding. This method is suitable for severely worn cylinders and achieves height locking through physical restriction.

3. Wooden Structure Damage

1. Crack Repair

• Remove the original wedges and clean the dust and old glue from the cracks;
• Inject wood glue (use a straw for assistance with small cracks), clamp and hold until the glue beads out, wipe off the excess glue, and let it sit for 24 hours;
• If the crack is deep, make a butterfly key (wooden decorative piece) to cover the crack and enhance structural strength;
• Fill bottom cracks with quick-drying glue mixed with sawdust, and sand it smooth after drying.

2. Wedge Adjustment
   If the chair wobbles due to loose wedges, drive new wedges into the gaps and adjust the angle of the wedges with sandpaper for a tight fit. After adjustment, check whether the four legs of the chair are stable to avoid uneven local stress.

Repair Precautions: Before operation, confirm the structure type of the chair (hydraulic or wooden) to avoid mixing methods; wear protective gloves when using tools to prevent cuts; if the hydraulic system leaks oil or the cylinder fails completely, it is recommended to contact professional repair personnel to replace the parts.