A guy that was a respected member of this board, who is now posting at FBBO instead, said that the Mustang rear calipers need to be adjusted periodically. He said that sometimes the caliper pistons don't move out as the pads wear and that slack creates longer pedal travel.
Because of this, I pressed the parking brake pedal almost 20 times yesterday before going for a drive. The pedal travel was the best that it had ever been and I thought that I had stumbled upon the FIX for it all.
No, I did not.
Within a few miles, the pedal travel increased.....then the travel was long enough to trigger the warning light. The front reservoir was almost dry. The rearmost reservoir had about 1/2" of fluid in it.
I haven't checked the level in a few months but I found no leaks anywhere.
I went ahead and set up the Motive self bleeding tank and set to bleed the right rear corner first. I always slip some clear surgical tubing over the bleeder nipple with the other end into a bottle, all to contain the fluid and to minimize the mess. Clear fluid started coming through which was unexpected. I'm using DOT 5 fluid now. I guess when I bled the system last time, I didn't notice and didn't bleed it long enough to get all the DOT 3 out. Mixed fluids can result in a mushy pedal. I was getting inconsistent pedal feel for awhile. One time the pedal would have good feel, other times it might feel mushy. It was not confidence inspiring.
Out on the road, pedal feel is even and consistent now. The pads bite better once they warm up. I still can't get them to skid but they do slow the car down nicely. It is in no way dangerous, just not awesome. I may need to do some stops next to a modern car to see if they are comparable. If I'm on par with the Wife's car, I'll be impressed.