Aeroquip FCA0420 #4 Hose 20′ Air Brake Compressor Discharge Hose Connector. EST, MON to FRI. Brake > Electrical Connectors > Air Brake Compressor Discharge Hose Connector. Aeroquip FCA0420 #4 Hose 20. Aeroquip – FCA0420 – #4 Hose 20′ – Hose – AQP Racing Hose – 4 AN – 20 ft – Braided Stainless / Rubber – Natural – Each.