We had a right brake that was sometimes sticky, and a left brake that sometimes needed pumping. I made a perfect three pointer in nil wind on the centreline of a dry wide tarmac runway.
The right brake stuck slightly, and a turn started as I pumped the left brake. I then realised the rate of turn would take me round without leaving the runway, and stopped pumping heading for the edge. I could hear the alarm in the background as the ATCO asked my intentions. As I approached 270 degrees, I pumped like mad, the left brake responded, and I taxied to the hangar.
We fixed the brakes before the plane was flown again. So far that's my only ground loop. 1900 hours total, mainly in Jodel DR1050s