I really need help. My driveway is sloped and when I back out of the garage my 1999 SLK 230 has almost no brakes. It slowly rolls down the driveway. More pressure on the brake peddle doesn't help. The emergency brake will stop the car. After driving the car for a minute the brakes work perfectly. ..until the next morning..and the situation repeats itself. Do you think the booster is leaking or ??????

it does sound like you're losing vacuum overnight. check the booster for leaks- as well as the check valve in the supply line.

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1980 500SE/AMG Euro
1981 500SEL Euro
1982 380SEL
1983 300TD
1983 500SEC/AMG Euro
1984 500SEC
1984 300TD Euro
1986 190E 2.3-16
1986 190E 2.3
1987 300D
1997 C36 AMG
2003 C320T 4matic

past: 1969 280SE 4.5 | 1978 240D | 1978 300D | 1981 300SD | 1981 300SD | 1982 300CD | 1983 300CD | 1983 300SD | 1983 380SEC | 1984 300D | 1984 300D | 1984 300TD | 1984 500SEL | 1984 300SD | 1985 300D | 1986 300E | 1986 560SEL | 1986 560SEL/Carat | 1987 560SEC | 1991 300D 2.5 | 2006 R350

The SLK & other "Kompressor" engined cars have problems with vacuum in the morning..Possibly a PCV valve problem OR just the fact that the Kompressor is acting as a air pump & the engine isn't making any vacuum until it shuts off.

Some of the later Kompressor SLK's used an electric vacuum pump to help solve that problem.

I would start with a new PCV valve & cleaning of the oil separator.

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