E70 4.8i front Brake noise suggestions?

[rbryantaz]

My e70 is getting really bad brake noise in the front on slow stops.

I recently put new zimmerman rotors on and had Bosch pads. I changed them to Akebonos because they had a bit of a squeal even though they probably only had 10k miles on them. I didn't resurface the rotors because they still seemed pristine...

While changing them I noticed that the caliper bracket slide surface had an indentation that might not allow it to slide smoothly so I filed it flat and smooth again. I wonder if it is now too loose and I might need a new caliper bracket... Some cars have brake pad shims to adjust this out but I haven't found them for the X5.

The rotors are still clean with no gouges, lips, or rust. I also applied lubricant to the sliding surfaces, pins, and the back of the pads on the caliper piston contact point. The brakes seem to function just fine but make noise at low speed stops. I did try to bed them in with some repeated hard stops form 30-0 without ever holding the brakes when stopped and then let them cool.

The brakes now seem louder with the Akebono pads which were supposed to be a quieter pad but that hasn't been my experience...

I plan to change the brake fluid to see if it might smooth things out but don't really expect it to fix it.

What do people think?

-Rich

[jbash87]

TIS has a bold warning about not mechanically cleaning those surfaces. You may be in need of new brackets.

It also says NOT to grease the pins. What "lubricant" are you using?

[rbryantaz]

Originally Posted by jbash87

TIS has a bold warning about not mechanically cleaning those surfaces. You may be in need of new brackets.

It also says NOT to grease the pins. What "lubricant" are you using?

Thanks for the reply.

Interesting that they are that sensitive.

I have done a lot of brake jobs and these have been the most squealing. My 335 and e46s never squealed and I just did quick jobs without even adding any lubricant to the back side or pins. The sliders were already worn (had a 1-2mm x 5mm spot worn in them) and I had some squeal so I thought that it would be fine. I can see how they might be too loose after smoothing them out and could shift. That does make sense.

I used prestone brake parts lubricant on the pins. It was the best thing I could find at the autozone that day and I didn't feel like waiting for something else to ship. I used ATE plastilube on the back of the pads and sliders. It seemed far to sticky for the pins.

It looks like cardone has a reman brake caliper that also comes with the bracket so I will probably buy those and see if it solves the problem... New OEM brackets are $200 plus which is crazy and used ones might have the same issues I already have. I see that these calipers and brackets were used on the F15 aswell. I was hoping that there was a revision of the calipers or brackets along the way given that my 2007 is a first year model and first year models sometimes get corrections...

They require a core so they must remain them by welding up any gouges divets, etc and then machine them back to the factory tolerance. I will also see if there is a low mileage used F15 set out there given that they seem to be the same setup on the 35d and 40e X5s that had the 348mm front rotors (still researching that).

-Rich

[jbash87]

Originally Posted by rbryantaz

Thanks for the reply.

Interesting that they are that sensitive.

I have done a lot of brake jobs and these have been the most squealing. My 335 and e46s never squealed and I just did quick jobs without even adding any lubricant to the back side or pins. The sliders were already worn (had a 1-2mm x 5mm spot worn in them) and I had some squeal so I thought that it would be fine. I can see how they might be too loose after smoothing them out and could shift. That does make sense.

I used prestone brake parts lubricant on the pins. It was the best thing I could find at the autozone that day and I didn't feel like waiting for something else to ship. I used ATE plastilube on the back of the pads and sliders. It seemed far to sticky for the pins.

It looks like cardone has a reman brake caliper that also comes with the bracket so I will probably buy those and see if it solves the problem... New OEM brackets are $200 plus which is crazy and used ones might have the same issues I already have. I see that these calipers and brackets were used on the F15 aswell. I was hoping that there was a revision of the calipers or brackets along the way given that my 2007 is a first year model and first year models sometimes get corrections...

They require a core so they must remain them by welding up any gouges divets, etc and then machine them back to the factory tolerance. I will also see if there is a low mileage used F15 set out there given that they seem to be the same setup on the 35d and 40e X5s that had the 348mm front rotors (still researching that).

-Rich

Here is the warning. Seems like it is less about exact tolerances but rather a coating on that surface. I can't remember anything special about the surfaces in question when doing mine last year though. For what it's worth, I have zimmerman rotors and Akebono pads up front. I don't think I used any paste or grease on any surface and have no squealing.

I believe the thought process on not lubricating the pins is because lube will eventually attract dirt and debris which will then cause problems. I've only stopped lubing them recently myself but I never really had any issues in the past.

Keep us posted on whether new brackets fix your issue.

[rbryantaz]

I could see that I a rust prone climate. In AZ with some grease on them it wouldn't be a concern other than that they are looser now and could have the noise.

I am debating if I want to upgrade my 348mm front single piston calipers to the 50i 365mm dual piston calipers.

I have changed my rims to be 18" with AT tires so it would probably be a tight fit and it would mean new rotors and pads again too. If it weren't for that it would make sense to get the upgraded brakes given that the rears brakes and master cyl seem to be the same.

I think I will keep it simple and just order a reman caliper/bracket combo and bleed the system to see if that solves my issue. I will post back with results.

-Rich