Brake problems - mushy pedal

[lukasbmw]

Way back when I did my 5 lug conversion, I added a new booster and upgraded the master cylinder to that of a 750il.

After it was all said and done, my brake pedal had about an inch of travel inward before the pedal felt "hard."

This was about 2 years ago.

This was strange because the pedal used to feel "hard" right at the top.

Over the past year the pedal has begun to feel mushier and mushier. I took it in for a bleed 3 months ago but this did not solve the problem.

Today I had my shop machine the rotors and install new pads as the fronts were done. They also beld the system. The pedal is still very mushy. Braking performance is OK but the pedal has a very mushy feel.

What could be the problem? Booster? Master cylinder? Brake line leak?

[bimmer8604]

Did the bleed or flush. If they didn't flush, have them flush it.

With the car off, pump up the pedal till it gets hard, then keep your foot on the pedal, and start the car, pressure should release and the pedal will travel.

Could be a vacuum leak, the diaphram in the booster could have gotten cracked, or there is a check valve on the booster that could go bad, too.

Take it to a brake shop and have them look at it. But def. make sure they flushed the system and not just bled. They may also need to flush the ABS unit.

Kyle

[christophbmw]

since they bled/flushed the system i wouldnt geuss there is any air in the system (which would make it soft).
.....save yourself some diagnosing time and just replace the master cylinder. if that dont do it then your sol.

[PeaveyBassist]

.....save yourself some diagnosing time and just replace the master cylinder.

Why would you ever do that??? Save diagnosing time to be a parts changer? Why not diagnose the problem RIGHT and not have to pay an extra $150 when it wasnt the master cylinder? It COULD be the MC, but if it isnt, you just wasted $150 on it for nothing.

Will

[bimmer8604]

Why would you ever do that??? Save diagnosing time to be a parts changer? Why not diagnose the problem RIGHT and not have to pay an extra $150 when it wasnt the master cylinder? It COULD be the MC, but if it isnt, you just wasted $150 on it for nothing.

Will

exactly.

diagnosis is pretty damn important.

kyle