I have a leak at the front brake resv. on an 88 GS. I have determined that it is at the 'crush' washer closest to the resv. I cannot see a hairline crack in the resv. neck. I have replaced both washers with new ones and my local mechanic says to tighten til the leak stops. Did that and still a leak, tighten more...still leaks. I now fear I have stripped the bleed bolt, can this happen or is there still room to tighten? Replace the washers again? Anyone recommend something, aluminum, copper?