C152 pilot reported a brake malfunction on landing that resulted in a runway excursion.

Attributes
ACN	1693866
Time
Date	201910
Local Time Of Day	1201-1800
Place
Locale Reference	ZZZ.Airport
State Reference	US
Environment
Light	Daylight
Aircraft 1
Make Model Name	Cessna 152
Operating Under FAR Part	Part 91
Flight Phase	Landing
Route In Use	Direct
Flight Plan	None
Component
Aircraft Component	Normal Brake System
Person 1
Function	Single Pilot
Qualification	Flight Crew Flight Instructor Flight Crew Instrument Flight Crew Multiengine
Experience	Flight Crew Last 90 Days 92 Flight Crew Total 902 Flight Crew Type 30
Events
Anomaly	Aircraft Equipment Problem Critical Ground Event / Encounter Loss Of Aircraft Control Ground Excursion Runway

Narrative:

I landed on runway xx at ZZZ and everything went smoothly until I applied the brakes. When I applied the brakes at about 15 kts. And the left brake seemed to lock up on me which caused the aircraft to spin to the left. I used full right rudder to try and counter the spin but the aircraft had already started to spin to the left. I went just off the side of the runway. I notified ATC that I was okay and would try and move the aircraft back onto the runway after I checked to make sure everything looked okay. It looked alright so I taxied the aircraft back to the ramp to make sure everything was okay. The aircraft is being looked over now.

Original NASA ASRS Text

Title: C152 pilot reported a brake malfunction on landing that resulted in a runway excursion.

Narrative: I landed on Runway XX at ZZZ and everything went smoothly until I applied the brakes. When I applied the brakes at about 15 kts. and the left brake seemed to lock up on me which caused the aircraft to spin to the left. I used full right rudder to try and counter the spin but the aircraft had already started to spin to the left. I went just off the side of the runway. I notified ATC that I was okay and would try and move the aircraft back onto the runway after I checked to make sure everything looked okay. It looked alright so I taxied the aircraft back to the ramp to make sure everything was okay. The aircraft is being looked over now.

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.