Brake problems

[cmmacx]

My 1986 325 has two, possibly related, brake issues. Excessive pedal effort is required - and the pedal is a little spongy. Also, after coming almost to a full stop, in traffic typically, when pressure on the pedal is reduced, there is a brief grinding noise (my wife thinks it sounds like air escaping).
This car has fairly low mileage but I recently bought it and am uncertain of when brake fluid was last changed. Tests of booster function and air tightness (starting motor while depressing brake pedal, pedal goes down slightly; after turning motor off, pumping pedal and noting that pedal rises after 2nd or 3rd depression) were fine. I also checked the directional valve in the vacuum line - no problem.
Any ideas?

[jamin325i]

if you don't know car's history then do a proper brake bleeding. someone may have left air in a line.
i left air in a bimmer line once and it was scary to stop.

in a honda accord- mid-90's-a soft petal that goes down-like at a stop light- typically is an internal leak in a master brake cylin. with no external fluid loss.
i have not heard of this problem for bimmers nor do i know if master cylin. design is similar to the honda.

perhaps a grinding noise is a damaged disc pad? or a grabbing caliper?

[cubicleman]

I'd strongly recommend taking a look at your pads. I experienced a grinding noise once. Turned out that one of the pads had worn through and the base of the pad was eating into the rotor. The grinding noise was only noticeable as I was actually coming to a stop. The funny thing was that the worn pad was replaced at the same time as the pads to the wheel on the other side, yet those pads still had considerable life left. Never did find out what caused the inconsistency, but it hasn't happened since. Good luck.

[Wayne 962]

With an unknown car with brake problems, I would go through each system and make sure it's up to code - you'd hate to have brakes fail on you, and you have no idea what the previous owner did or did not do with the car...

-Wayne