In order for a hydraulic fluid to be approved by the various pump manufacturers for use in their products, it must qualify for acceptance according to certain test methods. Chief among these tests are the Denison HF-0, the Vickers 35VQ25, and the John Deere Sundstrand piston pump test.
The Denison HF-0 test evaluates hydraulic fluid performance based on flow, deposits, and wear in both a Denison P46 axial piston pump and a Denison T5D vane pump. Both pumps are run for 100 hours and are periodically disassembled for inspection. Obtaining satisfactory pump results is the largest step in the process for a fluid to qualify under the HF-0 Standard. In the past, the P46 and T5D pumps could be tested separately or “bootstrapped” with a 46 series motor to reduce horsepower requirements.
The Vickers 35VQ25 test measures the anti-wear characteristics of a hydraulic oil according to cam ring and vane weight loss in a 35VQ25 vane pump. A minimum of three cartridges are tested for 50 hours each. The first three, or four of five cartridges, must perform satisfactorily in order for a fluid to pass this test.
The John Deere piston pump test screens oils that cause corrosion of copper containing metals. A Sundstrand 22 series axial piston pump is operated for 25 hours. Water is then added to the test oil. The test is then run for 200 more hours. Over this time multiple parameters are monitored to determine the effect of the added water.