Where do you put hydraulic oil in a koken Comet chair?

To add hydraulic oil to a Koken Comet chair, locate the hydraulic cylinder beneath the seat. You may need to remove the seat upholstery or access panel to find the fill port. Use a suitable hydraulic oil and a syringe or funnel to carefully fill the cylinder, ensuring not to overfill. Always consult the manufacturer's instructions for specific guidelines on oil type and maintenance.