Believe it or not, that’s an extremely common question. 99.9% of the time, the elevator in question is a hydraulic elevator – typically from 2-8 floors. What causes that noise is a lack of hydraulic fluid in the reservoir. Whenever a hydraulic elevator system has a leak – of any kind – the fluid lost does not return to the reservoir (or tank), and the system then lacks the necessary amount of oil needed to push the piston the full length of travel in the hoistway. The result is air entering the line as the system cavitates. In short, when the elevator gets to the top floor, the noise you hear is the pump trying to push the piston without a sufficient amount of oil. It’s loud, and for those not in the know, it’s scary.
Some common reasons a hydraulic system would lose oil:
- A leaking seal around the piston
- Worn hoses
- Bad pump gaskets
- Worn valve seals or O-rings
- Collection means in the pit not functional
And more serious problems:
- Leaking supply piping (oftentimes underground)
- A hole (very small one) in the underground cylinder
Both of the last examples are very serious problems and are always extremely costly. Underground piping will most often get re-routed above ground if it is physically possible. A leak in the underground cylinder (or “jack”) requires removing the piston, pulling the cylinder out of the ground, redrilling the hole and replacing the cylinder. Pricing for those repairs are always in the thousands of dollars.
Whenever you’re faced with a repair of that magnitude, secure the services of a qualified elevator consultant and let him/her determine the seriousness of the problem, and when necessary, secure the prices of at least 3-4 other elevator companies to do the work. Whatever you end up paying a consultant for that service will be offset considerably by the amount of money you can save through the competitive bidding process.Posted under Information