ou also have the brake compensating valve in the rear brake line just above the rear axle. These can become plugged and cause hard bleeding on the rear brakes. It is a very simple and expensive device. It reduces the pressure to the rear brakes with a piston and spring. Very easy to take apart and clean. For some reason mine, and from searching here one other person required very hard initial pedal pressure to get it to bleed after reassembly. Not sure why, but it has worked great ever since. If you remove the rear brake hose at the inlet end and you still get no fluid, it probably is the brake compensator. Somewhere here someone posted a link to a group in Poland I believe who showed the compensator in great detail and they had found replacement seals from another vehicle that worked as the seals themselves are not available, just the whole valve. They even had a bench tester set up to calibrate the valve. I don't know the site, but it was very informative on many things about these cars. Search brake compensator here for more info.