[M980]

Hello All, having an issue with a softer brake pedal. It has been like that for a while now. Once the car starts with your foot on the brake, the pedal sinks a couple of inches and is soft. Driving the car, the brakes work fine, they stop well and if you hit them hard the car stops really quick but all with an inch or two of travel before the brakes engage. I want to get a firm pedal back though.

I have bleed the brakes twice now and still have the squishy feel. There are no visible leaks so I am coming to the conclusion that it must be the master cylinder. Is there any DIY for the correct process to replace the master cylinder. I have been searching the forms and cannot seem to find one. Any ideas? Thanks.

[M980]

Any thoughts?

[mikesunboxing]

i could use a decent DIY on this.

Did you do yours?

[Socket]

usually just air in the brake lines
I had to bleed mine about 6 or 7 times on one fluid change
There is a DIY on how to do the fluid change and use the ABS to prime the lines
Good luck

[mikesunboxing]

Thanks Socket. I had a look on here and couldn't find the DIY?

Can anyone forward we the link or page please?

[Volasko]

Originally Posted by M980

Hello All, having an issue with a softer brake pedal. It has been like that for a while now. Once the car starts with your foot on the brake, the pedal sinks a couple of inches and is soft. Driving the car, the brakes work fine, they stop well and if you hit them hard the car stops really quick but all with an inch or two of travel before the brakes engage. I want to get a firm pedal back though.

I have bleed the brakes twice now and still have the squishy feel. There are no visible leaks so I am coming to the conclusion that it must be the master cylinder. Is there any DIY for the correct process to replace the master cylinder. I have been searching the forms and cannot seem to find one. Any ideas? Thanks.

I had the same issues which was not solved by a proper bleeding procedure (activating the ABS and everything) so I thought it must of been the master cylinder. Have about $1k for parts and labour it solved absolutely nothing. I tried a few other E90 pedals of people I know and found it to be common. I decided to leave it as it still feels fine when driving. I was told that there was an O-ring that could potentially bleed air from the vacuum assist that could cause this but never got around to checking it properly. See this thread a while back, post 8 & 9 specifically:

https://www.e90post.com/forums/showthread.php?t=1421826

I also posted a video of what I was experiencing which sounds exactly what you have. As I said a whole new master cylinder didn't fix this.