Bad Casing???

Does anyone know a good way to show the client there elevator hydro casing is bad, even though it keeps passing load tests? But it keeps losing lots of oil. (40 gal last 3 months)

Have you tried parking the car at the top floor with a full load for 12 0r 24 hours, measuring the oil level in the tank, noting the position of the car and pulling the Main Line Switch? The test should be done with oil that is not too hot to begin with.

Install a new lock on the Machine Room door? No LOL, maintenance guy taking it home for his log splitter and tractor.

Is this maybe a sectional jack? I've had two on my route (three sections) over the years where the units exhibited the same symptoms you describe, and observing the lowest threaded joint... You guessed it...weeping oil. Then the ting tang test. Yep. Oil in the piston. Drilled, tapped and plugged the jack...twice before replacement.

I'm with John
The only thing I would add is, place a gauge on the valve and close the line between the tank and piston.

If there is no loss during your pressure tests I would put capacity in car, run it up, mark where sill is, pull and lock-out disconnect, check location to see how fast if any it's sinking, if no sign let set overnight. From there just eliminate where your loosing it. Shutting the gate valve off while having a gauge in will show if it's the valve. Of course if it still sinks with gate valve shut it's pipes or cylinder. Be aware, I've also seen the jacks fill.

U mean piston,oil can fill through a loose joint.i saw that one before.

yes, sorry. I meant piston

Douglas,
A 6" diameter x 40 foot long piston would hold almost 60 gallons of oil. And you say you added 40 gallons in the last 3 months. I would believe you would likely see the oil if you hung or landed the car, disconnected the piston, lowered the piston and looked inside.

Or is this a 100' long piston?
Also maybe someone else may have seen this or know? Can a piston fill to a point where it could hold enough to keep additional oil from pushing in?

Run the car to the top on inspection and tap on the piston in several places to see if the noise changes(hollow vs. not). If 40 gallons of oil are in the piston you will know.

I have also seen what I call a flapper leak, the rust or corrosion is semi-sealing the leak most of the time and with full load it holds even better(until it doesn't). I have left cars like yours fully loaded after a relief test many weekends and not found any movement. Once I showed up on Monday morning and the car was in the exact same spot a few feet above the bottom landing(this test the piston joints as well) then we left to get a cup of coffee and call the boss. When we got back from coffee and talking to the property manager we were shocked to find the car on the springs and it wouldn't even pressurize the jack. When we pulled the cylinder out of the ground there was a rusted hole the size of a dime near the bottom of the jack. Scary Crap.

Seen all the above and on two occasions fixed the problem with a hasp on the tank. These guys would steal enough oil the car wouldn't make the top 2 floors and not leave a drop on the floor. I bet we spent 10 grand on weight tests and crew time trying to figure it out!!!

We had one where a night time maintenance guy at a hospital thought it would be a good idea to borrow some oil out of the hydro tank to change the oil in his car. He didn't even make it out of the parking lot before his engine seized up.

Hahaha serves him right. We had one where the cleaning gal thought it was a trash compactor and threw 2 big bags of trash in the tank!!!!! What a mess. probably cost what she made in a year to get that one going again.

Yeah, we had the Greyhound depot in San Diego. Old water hydro pump unit was in the kitchen. Cook must have thought the tank was some type Insinkarater. You name it onion peels, coffee grounds, french fries and other garbage. Still running though............didn't smell to good.

Is this an oil job or a water hydro. We had a water hydro just recently checked out fine with weights. Had a flap on the casing opening and closing letting water out? Didn't move for 4 days with weights just ran it in normal service lost 10 gallons in a 2 day period!