It is either a clog in the line or the master cylinder has something clogging the rear port. That is probably the case. If it were the piston failing to rerun the front brakes would stick as well. I would check parking brakes return springs just for the sake of being safe.
Also the proprtioning valve could be clogged in between the front/rear split up to the rear left/right split.
I would try replacing the master cylinder first as it is an easy job and not too expensive.
If you could make test fittings for a vacuum pump, you could find the clog that way, but it is costly and tedious.
Witht the mileage, if you have never flushed the fluid, I would try a master cylinder.
Tuesday, June 5th, 2012 AT 7:28 PM