Hi all I'm new at this, and my car is getting closer to shake down runs, In cleaning up the chassis and repacing loose rivets I had to take the master cylinders off and when draining them I noticed the fluid was blue.. this car uses lookheed masters , I have some rebuild kits and the instuctions of these kits states using Girling dot 4 or 5 the question I have is which fluid is blue and whats compatable with girling dot 4 or 5? and help would be great.....John