When hydraulic oil turns black and deteriorates, it often leads to pressure fluctuations, jerky movements, and valve wear in injection molding machines, thereby disrupting normal mass production. Properly identifying the root causes and addressing the issue according to standard procedures can extend the service life of the hydraulic system.
I. Primary causes of hydraulic oil turning black
Cooler clogging, prolonged high-load equipment operation, and poor workshop heat dissipation lead to persistently excessive oil temperatures; this accelerates hydraulic oil oxidation, resulting in sludge formation and the oil turning black.
Internal metal wear debris and external dust enter the oil circuit; failure to replace the filter element over an extended period allows impurities to circulate, accelerating oil degradation.
Condensation and water leakage entering the fuel tank cause the fuel to emulsify, accelerating corrosion and deterioration.
Indiscriminately mixing hydraulic oils from different brands causes additive precipitation and the rapid formation of deposits.
II. Corresponding Solutions
Slightly blackened
Clean the cooler, replace all filter elements, strictly control the operating oil temperature, and regularly monitor oil parameters.
Moderately blackened
Drain the old oil, clean out sludge deposits from the reservoir, flush the lines, replace the filter element, and fill with new hydraulic oil.
Severely blackened and with an off-odor
Thoroughly clean the hydraulic system, inspect the cylinders and valve blocks for corrosion, replace aged seals, and refill with fresh oil.
III. Long-acting preventive measures
Use anti-wear hydraulic oil compatible with the equipment and avoid mixing different oil products; clean the cooler regularly; promptly replace dust boots and hydraulic tank breathers; replace filter elements according to the maintenance schedule; monitor and control the equipment's oil temperature; and periodically sample and test the hydraulic oil condition.
