Sounds like you don't actually have a problem with the reservoir reset - if the problem started when you applied the e-brake, you likely have a poor performing e-brake switch. You might still examine how much fluid is in the rear compartment of the reservoir. A common problem is that the fluid there drains out (for whatever reasons) and can only be refilled when the front compartment is overfilled and then the fluid overflows the partition and spills into the rear chamber.

Been too long since I worked with that body. The switch is likely behind the cardboard style kick panel.

Good luck.

Jim

__________________
Own:
1986 Euro 190E 2.3-16 (291,000 miles),
1998 E300D TurboDiesel, 231,000 miles -purchased with 45,000,
1988 300E 5-speed 252,000 miles,
1983 240D 4-speed, purchased w/136,000, now with 222,000 miles.
2009 ML320CDI Bluetec, 89,000 miles

Owned:
1971 220D (250,000 miles plus, sold to father-in-law),
1975 240D (245,000 miles - died of body rot),
1991 350SD (176,560 miles, weakest Benz I have owned),
1999 C230 Sport (45,400 miles),
1982 240D (321,000 miles, put to sleep)