Short answer
Use the hydraulic fluid type and ISO viscosity grade listed by the equipment or pump manufacturer. Confirm seal compatibility and how the new fluid will interact with the fluid already in the system. Keep the fluid clean with correct filtration, and use oil analysis to decide when it needs changing.
Hydraulic press and injection molding requirements
Hydraulic presses, injection-molding machines, lifts, and fixtures each list a fluid type and ISO grade, often ISO 32, 46, or 68. The pump manufacturer may set additional requirements. Use the most restrictive requirement that applies.
AW 32, AW 46, AW 68, or multi-viscosity hydraulic oil?
Anti-wear hydraulic oils are common in industrial systems running at steady temperatures. Multi-viscosity fluids are used where the equipment operates across a wide temperature range, such as outdoor or unheated areas. Follow the equipment builder’s guidance rather than choosing by name.
Keep the fluid clean
Particle contamination wears pumps and valves. Equipment builders often state a target cleanliness level using the ISO 4406 code. Replace filters on schedule, keep reservoir breathers in good condition, and filter new oil when transferring it into the system.
Water contamination is another common problem. Investigate milky or cloudy fluid promptly.
Plan a hydraulic oil changeover
Before switching products, confirm compatibility with the existing fluid and the system’s seals. Drain as completely as practical, replace filters, and follow the equipment builder’s flushing guidance. Label the reservoir with the fluid now in use.
Frequently asked questions
What ISO grade does my hydraulic system need?
Use the grade listed in the equipment or pump manual for your operating temperature range. ISO 32, 46, and 68 are common, but the manual decides.
Can tractor hydraulic fluid be used in an industrial press?
Only if the press manufacturer permits that fluid type. Tractor hydraulic/transmission fluids are formulated for shared transmission and wet-brake systems.
How do I know when hydraulic oil needs changing?
Follow the equipment schedule and use oil analysis to check particle count, water, and fluid condition.
General maintenance information. Always follow your vehicle or equipment manufacturer’s requirements and the current product data. Questions? Email [email protected].
