Why must you place a hydraulic elevator car on support posts before servicing the packing head?

A hydraulic elevator operates using a system where a column of oil is essential for lifting the elevator car. This oil is contained within a cylinder and exerts pressure on a piston, allowing the elevator to move up and down. When servicing the packing head, which is a crucial component that seals the cylinder and prevents leaks, it is imperative to ensure that the elevator car is firmly supported.

Placing the car on support posts effectively removes the weight from the hydraulic system, ensuring that any operations undertaken do not create undue pressure or risk of failure. If the elevator is not positioned correctly on support posts, the hydraulic pressure could potentially shift or cause an unsafe condition for technicians working on the packing head. It's essential to maintain safe service practices, and proper positioning prevents any hazards related to the hydraulic lifting mechanism.

This understanding emphasizes the importance of safety and correct procedure when maintaining hydraulic elevator systems, aligning with necessary protocols for ensuring both worker safety and equipment integrity.