Clean machine oil or vegetable oil

If the piston does not rise or handle the pressure when moving effortlessly, to check the oil Each valve box and to exclude air from the lines.
2 for the whole pressure test, pressure test using 1.25 times the working pressure, check the  oil equipment  Out to the maximum working stroke, the regulator 15 minutes, pressure gauge reading drops shall not exceed the test pressure4%; All oil should be no leakage; pressure drop in all, the gauge pointer back to "0"Bit, the part should be no damage, trolley shall not have significant deformation, moving parts, no catching phenomenon.
Three pairs of reliability test valve, the valve operating pressure adjusted (left +5, left +1) MPa Consecutive test five times,  oil expeller  valve opening and closing sensitive valve after each jump should not be less than the rated pressure gauge readings Working pressure.