Hi
Have just replaced rear pads and discs on 2011 Mazda 6 ts2,Previous pads were worn down a lot.Now after replacement have brake Judder worse when braking at the higher speeds.Have the pad pins located ok,Have cleaned the hub from any surplus rust,Greased contacts on edge of pads and the backs.Cannot seem to get rid of it.Done aver 1000 miles now,Dont know whether to try and put old discs back on in case new discs are out.Any suggestions would be appreciated,
Thanks

 

HI Grim_Reaper,

Thanks so much for replying.

The master cylinder (MC) did not come with a pushrod for the Brake booster(BB). For the Mazda 3 it appears to be a fixed position with no adjustments, nor could I find any adjustments on on the pushrod of the BB like some of the older systems in different vehicles. I even found a tool that someone sells for measuring and adjusting the rod's position, but since I don't have an adjustment, it doesn't seem applicable.

I did think of playing with the fork on the cabin side, but it bothered me that I had to adjust it. I also put back the original one (it worked OK for the most part) and the brake drag problem went away. I then went to the dealer to find an OEM MC and they said wow, it's rare for them to go bad, so rare that they would have to order one and it wouldn't be in for a couple months ad was double the cost! .

I went back to my local auto parts store and ordered a re-manufactured one that came in later that day (while waiting your response came in...). I installed it and it seems to work fine. My best guess is that the 3rd party replacement MC is slightly longer or different in some way that it isn't an exact match and was causing the problem. The remanufactured one was an original equipment MC that was rebuilt, so it should have the same dimensions as the original.

It's also possible that the first one I bought was "a lemon". Anyway, that's my story.

I do seem to have a case where go around 10mile per hour and lightly brake, that the pedal seems to gently drop. It always keeps the brakes engaged, and hard stops work, so it's not like the MC is leaking internally. Someone said I just need to bleed the brakes thoroughly, so I'm looking for confirmation on that. Your thoughts?

Thanks again for the reply and diagram, I appreciate it.