The reason for the change of the brake fluid is that the origional fill was girling dot 3. It was assumed that that would also be the replacment fluid. Brake fluid is hygroscopic ie: it absorbs moisture from the air. If you don't regularly drive the car and heat up the fluid to drive out the moisture it will corrode the aluminum cylinder bores. If you go to Castrol "GTLMA" you can probobly go alot longer than 2 years but it is cheap insurance. The reason your master cylinder is failing is common. The flush washed out all of the crud that helped seal the corroded bore. It is very likely that you will wind up rebuilding all 4 calipers also. If you have a 5 speed don't forget the clutch fluid which is the same and subject to the same problems. Many people have gone to silicone or dot 5 but it isn't recommended for several reasons including, water won't mix with the silicone so if any is in the system it will eat up the cylinders. David Teitelbaum vin 10757 --- In dmcnews@xxxxxxxxxxx, "Lynn Metz" <metzlynn@xxxx> wrote: > Group: > > I was just wondering why the owners manual suggests changing the brake fluid > so often and why so many list members emphasize this as well? Is this just > being extra careful or is it really needed. For example, my daily driver, > Firebird, has over 130,000 miles (12 years old)- brake fluid never changed - > never any problems. Now, I drained and replaced brake fluid this summer on > the DeLorean and now, about 300 miles later, the master is going out. I > assume the new fluid was too much for the old rubber in the master. (Or it > could be a coincidence) > Brian 16584 > ______________________________________________________________________ ___ > Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com. > > Share information about yourself, create your own public profile at > http://profiles.msn.com.