Elevator Jack Replacement
Before we dive into why and how you would need to replace the elevator jack, let’s discuss what the jack is.
What is the elevator jack (or cylinder)
The elevator jack is what moves a hydraulic elevator up and down. For the elevator to move up the jack becomes pressurized with oil. When the elevator comes down the hydraulic oil de-pressurizes the jack.
Single Bottom Jack’s vs. Double Bottom Jack’s
Single bottom jack’s (SBJ) were produced prior to 1971. As the name indicates, SBJ’s have only one bottom while double bottom jacks have an extra bottom. Double Bottom Jack’s were manufactured after 1971 until about 1989. Take a look at a diagram of the differences of a single bottom jack vs. a double bottom jack.
Why have a jack with two bottoms?
Hydraulic Elevator Cylinder Failure
Most Jacks are made of metals that can corrode. Since jacks are often underground they are exposed to dirt, debris and water that can corrode them over time. For a building owner this can be a disaster. Not only will your elevator be out of order for 6+ weeks, but also it is a major safety issue.
If the jack has a major failure, the elevator could free fall and cause harm to any passengers. Furthermore, there could major environmental impacts as well, especially with single bottom jack. The loss of oil can seep into the ground and water table. The building owner could be liable for environmental damages from the EPA.
A double bottom cylinder can still fail and need to be replaced. However, most of the time the double bottom will protect against some corrosion and prevent major oil seepage.
Elevator Jacks after 1989 have PVC lining
After 1989 elevator jacks were manufactured with a PVC lining. This protects the jack from corrosion and prevents the majority of hydraulic elevator cylinder failures.
Should I replace my elevator jack?
Unfortunately, it’s almost impossible to predict or prevent an elevator cylinder failure. Since the jack is underground there is no preventative maintenance procedures that can be done. if you start to notice excessive oil loss, you should be concerned.
If you have the budget for it and your elevator cylinder was made pre-1989 it may be worthwhile to proactively replace the elevator jack. Instead of having unexpected downtime of your elevator, you can have your elevator maintenance company proactively order the materials. Furthermore, you can warn your tenants and schedule the repair in an off season.
Elevator Jack Replacement Cost
The cost of your elevator jack replacement will vary by how many stops the elevator is. A two story elevator will require less materials and less labor than a six story elevator. A good rule of thumb is the cost can be anywhere from $30,000 – $70,000.
Beware of the hole collapsing
Although infrequent, when the elevator repair team removes the failed jack, the hole can collapse. This will extend the time of the repair and cost you more money. Unfortunately, there is nothing to be done about this, besides preparing for the worst. I recommend you get a budget range from your elevator maintenance company in case this happens.
If you are looking for help in determining if you should have an elevator jack replacement, or you need help reviewing a jack replacement proposal, shoot me a line and I can connect you with a vetted elevator consultants.