#2 hoist would not release the left brake. MSHA hotline called approx. 6:45 pm. ""MSHA"" returned the call and instructed the mine to call when the hoist was repaired. He was called approx. 10:05 pm. Electricians found a defective propotional valve control and replaced. The mine had access at all times to two routes of travel and escape via our #1 hoist and #2 skips.