Office Chair Sinking

Office chair sinking is usually caused by gas spring failure, seal aging, or loosening of the adjustment mechanism, and can be resolved by checking screws, adjusting the locking mechanism, or replacing the gas spring. Safety precautions should be taken during repairs.

Common Causes

1. Gas Spring Failure
   The gas spring is the core component of an adjustable office chair, responsible for bearing weight and height adjustment. If there is internal gas leakage (such as due to seal aging or part damage), the chair will be unable to maintain the set height, resulting in "automatic sinking." For example, after prolonged use, the seal ring of the gas spring wears out, leading to slow gas leakage, which is a common cause of sinking.

2. Seal Aging
   The seal ring is designed to lock the gas inside the gas spring. Rubber seals can age, harden, or wear out over time, leading to gas leakage and subsequent chair sinking.

3. Loosening of the Adjustment Mechanism
   If components such as the base plate or locking screws at the bottom of the chair become loose, the chair will not be able to lock its height even if the gas spring is functioning properly. For example, if the screws are not tightened or the locking mechanism is misaligned, the chair will not stay locked in place.

Repair Methods

1. Check and Tighten Screws
   Invert the chair and inspect the adjustment screws at the bottom as well as the screws connecting the gas spring for looseness. Use a screwdriver or wrench to tighten them one by one, ensuring all connections are secure.

2. Adjust the Locking Mechanism
   If the screws are not the issue, check if the locking mechanism is stuck or misaligned. Manually adjust the locking device (such as by rotating or pushing/pulling) to test if the height adjustment function is restored.

3. Replace the Gas Spring
   If the gas spring is confirmed to be damaged (such as due to gas leakage or internal part breakage), it needs to be replaced with a new one. Steps for replacement:

• Apply lubricant to the joint between the gas spring and the base, and let it sit for 1-2 hours to penetrate;
• Use a pipe wrench to grip the gas spring and rotate it for removal, or gently tap it with a rubber mallet to assist in loosening;
• When installing the new gas spring, ensure it is tightly connected and not tilted.

4. Temporary Repair Method
   If you do not want to replace the gas spring, you can wrap a hose clamp around the cylinder and tighten it, or use a PVC pipe to cover the cylinder to fix the height. However, this is only a temporary solution, and long-term use may affect stability.

Precautions

• Before repairs, choose a well-ventilated, well-lit, and flat surface, and prepare tools such as a pipe wrench and rubber mallet.
• Do not drill, saw, heat, or manually release gas from the gas spring, as this may cause internal pressure imbalance and lead to explosion risks.
• If the chair is still under warranty, contact after-sales service first to avoid voiding the warranty due to self-repair.