e34 540 brake problem

[bmw540]

Hello,

I have just bought a 540 with brake problems.

My first thought was the "bomb" needs replacing as the pedal is hard but after traveling down south over the weekend I noticed that there is no brake dust on the back wheels and it looks like that back brakes are not even working. I also noticed that there is a little amount of brake fluid under the master cyclinder which looks like it has been there for some time.

Any ideas?

[Paul in NZ]

what is the problem?


Hello,

I have just bought a 540 with brake problems.

My first thought was the "bomb" needs replacing as the pedal is hard but after traveling down south over the weekend I noticed that there is no brake dust on the back wheels and it looks like that back brakes are not even working. I also noticed that there is a little amount of brake fluid under the master cyclinder which looks like it has been there for some time.

Any ideas?

[bmw540]

Hard pedal and seams the back brakes are not working. Looking through the other posts seams like it could be the master cylinder.

[Paul in NZ]

you already said that.So a hard pedal and little braking effect?

[632 Regal]

full power flush and new fluid should get ya rollin! This is supposed to be done every 2 years bro.

[winfred]

no dust doesn't mean that the brakes aren't working, most likely theres some low dusting pads installed, besides if the rear circuit was blown on the master cylinder you would have a squishy pedal, hard pedal is probably something to do with the booster, usa 540s run a dual diaphram vacuum booster i am not sure whats on the euro cars, a bomb is a part on a hydro boost system (they go bad when they rupture internally and fill with fluid) if you have vacuum there may be a vacuum leak or the booster ruptured (or one i've been seeing a lot lately, a air leak where the master cylinder bolts to the booster)

[BillionPa]

try this: get the car up in the air, spin the rear wheels, and have someone push the brake pedal.

[tim s]

i bought it at fcpgroton & found out later everything from there is crap & does not last long.
i plan to replace it again next year.
tim s.

[bmw540]

good ideas... will go to a brake shop this weekend comming and see what they think is going on. Will suggest, brake fluid flush, rekit the back brakes, change the bomb and check the master cylinder. If that does not work will be scratching my head.

Already falling for the V8 sound!!

[632 Regal]

Hahaha...even I had to do a personal test of their crap. Everything I bought has had to be replaced including the thrustarms 3 times and their shot again. All within weeks of install.

i bought it at fcpgroton & found out later everything from there is crap & does not last long.
i plan to replace it again next year.
tim s.

[winfred]

the new guy at my shop got a hamburg technic front end kit for his e30 from ebay and the "m3" bushings didn't last a month


Hahaha...even I had to do a personal test of their crap. Everything I bought has had to be replaced including the thrustarms 3 times and their shot again. All within weeks of install.

[bmw540]

Just had the back brake capillars rekited and brake fluid flush. This has made the car feel alot more relaxed and happy to cruise. The pedal feels better but not perfect so going to get the 'bomb' replaced and hope that sorts it all out.