Narrative:

Our flight took us from ZZZ1 to ZZZ on the ground. I noticed the #1 hydraulic quantity was low, so I xferred fluid from the #2 side to the #1 side. This is completely routine. About 1/2 way to ZZZ, I noticed that the #1 side had dropped a little but I had seen that before and simply monitored the #1 quantity. As the flight progressed, I noticed that the #1 quantity appeared to be dropping very slowly. At this stage the quantity had not reached a level where I believed we'd run out of fluid before we arrived in ZZZ. The first officer and myself discussed the various things that might happen and how we should proceed. As it turned out we had to add power to clear the runway. The #1 hydraulic system provides service to: normal brakes, inboard roll spoilers, flaps, and the #1 rudder actuator. We got the flaps down to the landing confign and made a normal landing. The first officer (PF) made some comment after the landing that the control became somewhat sluggish. After we landed and slowed down, I took the controls and tested the toe brakes. They didn't work at all. I proceeded to the gate slowly using the emergency brakes to slow the taxi speed only a couple of times. The investigating mechanic found an improperly installed hydraulic line that was being abraded by the normal operation of the landing gear. A small hole got worn into the steel tube by the landing gear mechanism causing the leak.

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Original NASA ASRS Text

Title: A DEHAVILLAND DASH 8 ON APCH EXPERIENCED LOSS OF #1 HYD SYS PRESSURE AND QUANTITY CAUSED BY AN IMPROPERLY INSTALLED HYD LINE.

Narrative: OUR FLT TOOK US FROM ZZZ1 TO ZZZ ON THE GND. I NOTICED THE #1 HYD QUANTITY WAS LOW, SO I XFERRED FLUID FROM THE #2 SIDE TO THE #1 SIDE. THIS IS COMPLETELY ROUTINE. ABOUT 1/2 WAY TO ZZZ, I NOTICED THAT THE #1 SIDE HAD DROPPED A LITTLE BUT I HAD SEEN THAT BEFORE AND SIMPLY MONITORED THE #1 QUANTITY. AS THE FLT PROGRESSED, I NOTICED THAT THE #1 QUANTITY APPEARED TO BE DROPPING VERY SLOWLY. AT THIS STAGE THE QUANTITY HAD NOT REACHED A LEVEL WHERE I BELIEVED WE'D RUN OUT OF FLUID BEFORE WE ARRIVED IN ZZZ. THE FO AND MYSELF DISCUSSED THE VARIOUS THINGS THAT MIGHT HAPPEN AND HOW WE SHOULD PROCEED. AS IT TURNED OUT WE HAD TO ADD PWR TO CLR THE RWY. THE #1 HYD SYS PROVIDES SVC TO: NORMAL BRAKES, INBOARD ROLL SPOILERS, FLAPS, AND THE #1 RUDDER ACTUATOR. WE GOT THE FLAPS DOWN TO THE LNDG CONFIGN AND MADE A NORMAL LNDG. THE FO (PF) MADE SOME COMMENT AFTER THE LNDG THAT THE CTL BECAME SOMEWHAT SLUGGISH. AFTER WE LANDED AND SLOWED DOWN, I TOOK THE CTLS AND TESTED THE TOE BRAKES. THEY DIDN'T WORK AT ALL. I PROCEEDED TO THE GATE SLOWLY USING THE EMER BRAKES TO SLOW THE TAXI SPD ONLY A COUPLE OF TIMES. THE INVESTIGATING MECH FOUND AN IMPROPERLY INSTALLED HYD LINE THAT WAS BEING ABRADED BY THE NORMAL OP OF THE LNDG GEAR. A SMALL HOLE GOT WORN INTO THE STEEL TUBE BY THE LNDG GEAR MECHANISM CAUSING THE LEAK.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.