First off, I'm not an owner. I run a brake shop in Sarasota Florida and have a very loyal customer with an '89 780 Bertone turbo. For some time now he has experienced the following brake symptoms - Low pedal pressure, sinking pedal, hard pedal, and temporary caliper binding which releases under no specific circumstances!! The repairs done before he brought in to me (done by local Volvo dealer) - NEW master cylinder, NEW calipers - all of them, new booster, new pads, new hoses and lines, and new vacuum valve for the booster. None of these have solved the problem and I'm scratching my head as to what to try on this car. I'm going to remove the brakelight switch in the morning and see if it is possibly sticking open and holding the pedal partly down (common affliction on Chryslers) and if that doesn't correct the condition I'm going to unhook the ABS unit power and see if that helps. I have the car as long as I need it, with no budget constraints, on the condition that I FIX it! It's a beautiful car and a great customer so I'm hoping this is a problem someone else has experienced and successfully corrected. Thanks!