Break Pedal Goes To the Floor when Breaking

[bimmer325imt]

Wow, in the last few days I have noticed my break pedal has gone down to the floor. My first instinct was that my E30 fluid level must be low, a leak in the break lines or Master Cylinder is kaputt. I ckd the break fluid level on the reservoir which said refill. So I put Dot 4 fluid in and so all was well ,so I thought, for the next couple of days. So I did visual ck of any leaks on break lines which showed no sign of leaks. So I ckd the master cylinder and noticed leak btwn master cylinder and the reservoir. It had slow constant drip from the front end of the reservoir. I ckd my bentley book which indicated that the reservoir sits on top of master cylinder held by 2 grommets. I figured lets replace those first before replacing master cylinder. I called Russell BMW which didn't have them on sight but would have them the next day and they did. Wow I said. I have not replaced the old with the new yet. I will keep you all posted.

[John in VA]

I had the same symptom on our '85 325e. I replaced the brake master cylinder (the ATE cylinder came with 2 new grommets), cleaned out the reservoir, pressure bled and problem solved. Original one only lasted 24.5 years and 165K miles.