Repair a barber chair that does not lift correctly by checking and refilling the hydraulic fluid. Locate the nut for filling the reservoir, and remove it. Using a funnel, top the chair up with hydraulic fluid from a barber supply or automotive store. Refilling the chair with fluid sometimes introduces air into the system that you can remove by lifting and lowering the chair several times.
When checking the hydraulic fluid level, lower the chair to the lowest position. Adding oil when the chair is in the raised position causes the reservoir to overflow when lowering it.
Hydraulic barber chairs use foot pedals to raise and lower the chair. One foot pump moves hydraulic fluid, which compresses very little, through two cylinders in a closed system to lift the chair. The second pedal opens a valve that allows the fluid to flow back into the reservoir due to the weight of the customer and the chair.
The system allows the barber to lift the weight of the customer and the chair with relatively little pressure on the foot pedal. However, if the chair is low on fluid, pressing the foot pump introduces air into the system. Unlike hydraulic fluid, air compresses easily, so the chair remains at the same level.