The piston seals in all four calipers are bad. You can rebuild them, but most mechanics won't for liability reasons -- they get sued and lose big dollars if something goes wrong, and they are not responsible if they install new or third party rebuilt brakes.

Probably the best course of action is to install new calipers all round -- send the old ones back as rebuild cores, this will save you some cash.

Both you and the mechanic need to know what caused them to leak, though -- for you, to prevent this again, and for him to keep customers. I'd never take a vehicle back to a shop where the seals got destroyed doing a very simple brake pad replacement!

Peter

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1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!