Brake pedal travel issue - F80 M3

[patrickd_21]

Hi everyone,

Reaching out for help here as I'm at my wits end with the brakes on this car.

I bought myself a 2016 M3 with 5000 miles on pretty much 1 yr ago exactly. It's my daily and my lapping car at the moment.


When I bought the car, I slapped on some DTC-60 pads, Castrol SRF fluid, and off I went. The car was great all year and I got in 6 events.

The only complaint I had was that the pedal would get a tiny bit soft at the end of a 20min session. Probably due to the stock rubber lines expanding 17min into a hard session. Also, lots of wear on the outside of the tires


So over the winter I went out and bought stainless steel lines and camber plates. Had them installed by a shop, did a brake fluid flush, and was ready to start the year.


HERE is where the problems started.


At my first event, after a warm up lap, I started getting hard on the brakes and almost instantly, the brake pedal became very strange. The first 2-3 inches of pedal did nothing, and then all of my brakes were in the last 1-2 inches. I need to specify here that the pedal feel in the last 2 inches is good. Brakes are rock hard and I can brake HARD going into corners, it's just that since the pedal travel is so long and the brakes are all in the last few inches, modulation is difficult. I can do a full 20 min session going hard braking deep into braking zones, and it does not fade.

When I get off the track and the brakes cool, the pedal feels almost 90% better, but never perfect. I cannot replicate the low engagement point of the brakes in the street.

Here is the list of things I've tried that have had 0 impact on making it better:

- I thought there was maybe air in the system. Bled the system like 10 times. 2-3 times the traditional way. Once with a vaccum bleeder. 3 times with a power bleeder. Bled the ABS 3 times. Did a full fluid flush. I did it about 3 times. Another shop did it twice. Another shop did it 3 times. Another shop did it once

- I thought that since the issues started right after I did the brake lines, maybe it was the lines the issue. Swapped back to stock lines. Brakes still feel terrible, maybe even worse.

- Tried different pads (PFC-08). No difference


I'm getting real tired of this . 3 shops have bleed the brakes. I'm convinced there is no air in the system. I went back to my setup last year when everything was working well and that didn't fix things.

At this point I'm starting to get tired of throwing money at the issue and want to see if anyone has had this problem before. If no one has, my next step will probably be to rebuild the front calipers.

Please help lol

[ThatM3tho]

I sorta have the same issue. I drove a f80 with normal braking but end up buying another f80. After a few days I started to feel the braking issue. Pretty much what your describing. The previous owner provided maintenance paperwork which included brake fluid flush. I figured they did it wrong so I did one as well with a power bleeder. The car felt significantly better but 3 days later back to the same issue.

If you found any solution please share!