My 95 deisel C250 was stood for 5 months when first took it out after approx 5 miles of running great I noticed that it was getting slower as if running out of fuel I coaxed it till it stopped with smoke coming fropm the rear wheels.

I left the car for about 4 hoursd drove home very slowly no probs. removed the wheels the pads were rusted so i replaced them the discs spin freely . went out a couple of times no probs even went 25 mile round trip then a couple of days later went out after 5 or 6 miles the same again?

The pads are relesaing ok the pistons move freely was told to change the brake fluid tried to drain manually and with a pump cant gat more than a spurt at a time?
Can anyone help please. The car is souund passed the MOT (on the 25 mile trip) has done 82K miles.