Eaton 155S5-4 - Aeroquip 145/155 Hose Half -4 (1/4")

The Eaton 155S5-4 is an Aeroquip 145/155 Series Hose Half (Style I/II) for AN size -4 (1/4"), designed to attach directly to the flexible hose end of an aerospace hydraulic line. Rated to 3000 PSI and fully compatible with petroleum-based MIL-H-5606 and MIL-H-83282 hydraulic fluids, this narrow-bore fitting installs on the hose side of a ground service quick-disconnect coupling pair. Nitrile seals provide reliable compatibility with petroleum-based hydraulic media across a temperature range of -65°F to +275°F (-54°C to +135°C).

Hose-End Installation Advantages

• Style I/II compatibility allows mating with both hose-to-hose and hose-to-bulkhead halves
• Self-sealing upon disconnection — automatic valve closure eliminates fluid spillage
• The compact 1/4-inch bore delivers precise, low-volume flow control for servo actuator circuits and similar circuits
• Aluminum alloy construction minimizes weight without sacrificing structural integrity

The Aeroquip 145/155 Series employs a blunt-start quick-lead threaded ratchet lock — rotated by hand and secured by ratchet teeth engaging a lock spring assembly for vibration-resistant positive engagement. Coupling and decoupling requires no tools — a single-hand turning motion is sufficient. The 155S5-4 is certified to MIL-C-5502, MIL-DTL-25427B, and SAE AS5440 Type II, meeting military hydraulic service requirements for U.S. military aircraft ground operations. It is compatible with MIL-H-5606 (red) and MIL-H-83282 (fire-resistant) hydraulic fluids.

Applications

• Military aircraft hydraulic ground service lines (servo actuator circuits, instrument hydraulic lines, and brake accumulator systems)
• Hose-end installation on flexible hydraulic assemblies
• MRO shop hydraulic servicing equipment
• Aerospace OEM hydraulic hose assembly