Since we're posting non-MB brake problems I have a weird one. A friend has a '97 Volvo 850 wagon with ABS. Her brakes developed a somewhat mushy brake pedal but will 'pump up' more solid. Not scary but definitely not the firm pedal feel I expect from an expensive European car. No visible leaks or loss of brake fluid. Bleeding the rears restores a solid pedal for awhile but after a few weeks or months the brakes are mushy again.
Any opinions or suggestions?

Thanks, Mark

__________________
DrDKW