I wanted to bleed my brakes properly - rear right, front left, front right and rear left. But the rear left 10m bleed nut is jammed and the 10m spanner is slightly bigger than the nut so it keeps slipping. The same spanner works fine on the other three. So i tried jamming a 9m on it but it wont budge. Any ideas?

 

hopefully your using the box end of the wrench. since its a little worn and a 10 is too big a 9 too small try using a standard wrench. it my fit just inside those other 2. when you get it loose replace the bleeder. hopefully that will work