Phillips 66® X/C 5606J and X/C 5606A Aviation Hydraulic Fluids are mineral oil-based, high viscosity index, ashless (zinc-free) antiwear hydraulic fluids designed to meet the severe demands of aerospace and industrial applications. They have excellent oxidation resistance and outstanding low-temperature properties for use over a wide temperature range. They provide excellent wear protection for hydraulic pumps and motors, protect hydraulic system components against rust and corrosion, and are resistant to excessive foam buildup that can cause poor or sluggish hydraulic system response.

You are currently viewing X/C® 5606J & X/C® 5606A AVIATION HYDRAULIC FLUIDS

Features & Benefits

  • Very high viscosity index for use over a wide temperature range
  • Outstanding low-temperature properties
  • Excellent wear protection
  • Resists deposit formation and viscosity increase due to oxidation
  • Protects against rust and corrosion
  • Good foam resistance
  • Does not contain zinc or other heavy metals


  • X/C Aviation Hydraulic Fluids are recommended for use in non-pressurized systems operating between –54°C and 90°C (-65°F to 194°F), and in pressurized systems operating between –54°C and 135°C (-65°F to 275°F) at pressures up to 3,000 psi.(1) Typical applications include:
  • Aircraft and missile control systems, autopilots and shock absorbers
  • Auto wreckers, boom trucks and electrical service equipment (cherry pickers) where all-weather performance is required
  • Industrial robotics
  • Hydraulic systems that require a “super clean” fluid for extended service life and reliability (X/C 5606J)

    (1)Note: Do not use these fluids in hydraulic systems with natural rubber elastomers.

Technical Details

  • ISO Grade: 15
  • Licenses & Approvals

    X/C 5606J Aviation Hydraulic Fluid meets the requirements of:#U.S. Military Specification MIL-PRF-5606J (supercedes MIL-O-5606, AN-O-336, AN-VV-O-336 and AAF-3580)

    X/C 5606A Aviation Hydraulic Fluid meets the requirements of:#U.S. Military Specification MIL-H-5606A (obsolete)

    Additional Details

    ISO Grade 15
    Gravity, °API 31
    Specific Gravity @ 60°F 0.871
    Density, lbs/gal @ 60°F 7.25
    Color, Visual Red
    Flash Point (PMCC), °C (°F) 90 (194)
    Pour Point, °C (°F) -64 (-83)
    Viscosity, Kinematic
    cSt @ -54°C 2450
    cSt @ -40°C 495
    cSt @ 40°C 13.5
    cSt @ 100°C 5.1
    Viscosity Index 382
    Acid Number, ASTM D664, mg KOH/g 0.05
    Copper Corrosion, ASTM D130, 17°C (160°F), 72 Hours 1b
    Dielectric Strength ASTM D877, KV (At the point of manufacture) 49.6
    Evaporation Loss, ASTM D972, 71°C (160°F), 6 Hours, wt % 13.6
    Foam Resistance, ASTM D892, 75°F 25-0
    Four-Ball Wear, ASTM D4172, Scar Diameter, mm 0.65
    Gravimetric Filtration, FTM 131, mg/100 ml, 0.45 microns @ 25°C
    Filter Time, minutes 6
    Particulate Contamination, FTM 3012, Automatic Counter
    Particulate Size, microns
    5-15 1200
    16-25 175
    26-50 60
    51-100 5
    100+ 0
    Water Content, ASTM D6304, ppm 60
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