I am changing oil for the first time in 20 yrs on my Cat 530 pumps. Busy 6 bay. Why does a High Pressure Cat Pump oil container only have 21 oz when the 530 pump specs says add 25 oz? This is what Kleen Rite sent me. Before anyone goes saying how important it is to change the pump oil, don’t drink that kool aid. Unless it has been contaminated with water, it doesn’t go bad.