Aeroquip FCA0403 #4 Hose 3′ Air Brake Compressor Discharge Hose Connector. EST, MON to FRI. Brake > Electrical Connectors > Air Brake Compressor Discharge Hose Connector. Aeroquip FCA0403 #4 Hose 3. Aeroquip – FCA0403 – #4 Hose 3′ – Hose – AQP Racing Hose – 4 AN – 3 ft – Braided Stainless / Rubber – Natural – Each.