C172 pilot reported a loss of control and taxiway excursion due to a loss of braking system.

Attributes
ACN	1599329
Time
Date	201812
Local Time Of Day	0601-1200
Place
Locale Reference	ZZZ.Airport
State Reference	US
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	Skyhawk 172/Cutlass 172
Operating Under FAR Part	Part 91
Flight Phase	Taxi
Flight Plan	None
Component
Aircraft Component	Normal Brake System
Person 1
Function	Pilot Flying
Qualification	Flight Crew Instrument Flight Crew Private
Experience	Flight Crew Last 90 Days 30 Flight Crew Total 233 Flight Crew Type 215
Events
Anomaly	Aircraft Equipment Problem Less Severe Ground Event / Encounter Loss Of Aircraft Control Ground Excursion Taxiway

Narrative:

Upon initial taxi for the day; aircraft experienced brake failure. Taxi instructions were to taxi from north side of airport to runway xx via K hold short of runway xyr. Approaching xyr; cleared to cross runway xyr to taxiway D. Was utilizing right rudder pedal to turn aircraft nose wheel steering along with differential right brake during right turn onto runway xyr. As we were completing the turn to exit runway xyr; the right brake completely failed. Winds were reported 180/16g26 at the time of taxi. Attempted to use full right rudder input and crosswind aileron controls for taxi to clear the runway. Once clear of the runway on taxiway D; used remaining pressure in left brake to bring the aircraft to a stop. The aircraft came to a safe stop with only the right main landing gear remaining on the hard surface. There was no aircraft damage or injuries. Reported the situation to ATC over ground frequency and coordinated for a tug to return to maintenance.

Original NASA ASRS Text

Title: C172 pilot reported a loss of control and taxiway excursion due to a loss of braking system.

Narrative: Upon initial taxi for the day; aircraft experienced brake failure. Taxi instructions were to taxi from north side of airport to RWY XX via K hold short of RWY XYR. Approaching XYR; cleared to cross Runway XYR to Taxiway D. Was utilizing right rudder pedal to turn aircraft nose wheel steering along with differential right brake during right turn onto RWY XYR. As we were completing the turn to exit Runway XYR; the right brake completely failed. Winds were reported 180/16G26 at the time of taxi. Attempted to use full right rudder input and crosswind aileron controls for taxi to clear the runway. Once clear of the runway on Taxiway D; used remaining pressure in left brake to bring the aircraft to a stop. The aircraft came to a safe stop with only the right main landing gear remaining on the hard surface. There was no aircraft damage or injuries. Reported the situation to ATC over Ground frequency and coordinated for a tug to return to maintenance.

Data retrieved from NASA's ASRS site 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.