Your looking in the wrong place. Hydraulic noise problems are are generated from a defective part; pump, motor, valves or hoses. 
 
If the noise is there when the elevator is going up start with the pump, plugged filter bypassing or worn out valve. If the noise is only there when the elevator is lowering, it most likely is a inner linning in the return hose or a worn and defective valve. Either way, call the elevator maintanance company and ask their opinion. Also check the certification to make sure it is current. Sometimes a good service is all that needed. That should be an annual item in your reserve study.GR

You stated new condo. Check to see if builder warranty is still in effect. If not, the HOA will have to foot the bill because it is a defect outside your responsibility. 
 
My suggestion is to have your drywall removed from the wall which has the elevator on the other side. Then special sound proofing material can be added or replace existing material. A sound engineer should be engaged to determine the exact solution.

Did you purchase this condo? If so, there is no way the previous owner did not know of this unbearable noise. Did the realtor do an open house? If so, he/she would also have been aware of the noise. That's an easy lawsuit (in CA, you have 36 months to file after close). 
 
If you are a renter, I would recommend you buy, rent (equipment rental store) or borrow a quality noise decibel meter. Once you'v established that the noise is above recommended levels (you can find these levels on the internet), you can force your landlord to take action with the HOA. In California, you can withhold rent until an 'uninhabitable condition' is remedied by the landlord. 
 
Good luck! 
 
Bette Cessna, San Diego