Flight Crew Air Transport Pilot (ATP)
Aircraft Equipment Problem Less Severe; Flight Deck / Cabin / Aircraft Event Smoke / Fire / Fumes / Odor
General Maintenance Action
Aircraft
After landing; we used mostly reverse thrust to slow the aircraft and exited the runway. We had to use only minimal braking to stop the aircraft at the gate. However; when the main cabin door opened; the rampers came up and told us to look at the wheels (on the aircraft left side) because they were smoking. I went outside to look and saw that the wheels were in fact smoking. Based on previous experience with a brake overheat issue that nearly resulted in a fire; and because I thought it was the safest course of action; I preemptively called ARFF to come to our gate. We also made a phone call to Dispatch to inform them of the situation. The passengers deplaned normally during this time. The smoke was not thick enough to be readily noticeable to passengers; nobody became alarmed. After the firefighters arrived; they determined that the brakes did not overheat as we suspected; but rather some sort of fluid (hydraulic fluid) had dripped on the brakes and was evaporating visibly. The firefighters measured a brake temperature of only 140 C. They left and maintenance showed up. They determined that there was a hydraulic leak in the nacelle; above the wheels. The aircraft was written up and handed over to maintenance.
Dash 8 Captain reported ramp personnel spotted smoke in the brake area after parking at the gate. Cause of the smoke was determined to be hydraulic fluid leaking onto the brake area.