So I replaced my pads, master cylinder, booster, and rubber brake lines. However, after bleeding and bleeding and bleeding....my brakes still suck. However, I just noticed that air is sucking in where the master cylinder bolts to the booster. Like if I spit where they connect it gets immediately sucked into the booster. I'm thinking that may be a problem. I'm not losing or leaking any fluid. Could the master cylinder just need to be reseated, or could this be a sign that I installed a bad booster? Thanks for any ideas.

Sounds like a bad booster. I don't think there should be any vacuum there at all. That kind of leak will also cause lean condition.

Your probably right. It seemed like the pedal was holding some pressure though. However the pedal also feels real low all the time, so it's hard to tell. Maybe the booster I got sat on the shelf to long

just bought my 99 d2 and it has a soft peddle too, other previous owner said they had the brakes bleed, then a new mast cylinder installed with another bleed and still has a lot of peddle movement. im going to look into frozen slide pins at the calipers all around as being my d2's problem first and then look into other possibilities after. i can hit the brakes with a good amount of motion then let off the peddle and quickly push them again and the peddle grabs much quicker and much less peddle movement, also stays firm without feeling soft nor does it sink. so maybe check slide pins?

Symptom of marginal system that requires bleeding, has a small leak or has moisture in fluid.
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