Airy Brakes

MERCEDES BENZ
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DSMOSS
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1966 Mercedes 230 straight 6

I recently purchased this car from a person in Utah. Upon arrival in Texas the brakes didn't work. The previous owner swears they worked when the car was loaded on the truck. Assuming that is the case, here is the problem(s):

When the brakes are pressed there is a loud air noise down by the pedal. Losing air.

When the car in on and in park and the pedal is pressed the car idles HIGH.

When the car in on and in gear and the pedal is pressed the car idles LOW and occasionally stalls out.

In every situation it is a very SLOW stop. The pedal, however, is not soft.

I've bleed the brakes 4 times. 3 times starting from the farthest from the master cylinder and one of those with the vacuum bleeder. The forth time I started with the one closest to the master cylinder.

I've checked the lines and don't see a visible leak.

Is there something else I should be doing before I start shopping for a new master cylinder?
Apr 27, 2007 at 2:56 PM
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GFIMOTORCARS
  • ASE Certified Mechanic
  • 673 POSTS
  • ASE Certified Mechanic
You have a vacuum leak at your brake booster. This is the air you are hearing. The boosters on these models sometimes develope internal leaks as seals break down. The booster itself will need to be replaced. Also when bleeding your brake system the order of bleeding should always go as such. Passanger rear. Driver Rear. Passanger front. Driver front.
Jan 11, 2009 at 12:30 PM
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