kenallwine

This is something I mentioned of in a post I put in the M5 forum (by mistake).
https://5series.net/forums/topic/125...age-need-help/

I recently put new rotors and pads on the front our 06 525xi (114,000 miles). Everything was fine for the past 100 miles or so. Now, I am getting a thumping noise when I get on the brakes with moderate force. Saturday we drove around normally doing errands with the family. Sunday morning, all of a sudden this noise is there. I only notice it when the car drops below 20mph. The more I listen to it the more it sounds like something is catching on every wheel/axle rotation (only under moderate braking force). It does not sound or feel like a warped rotor (these are new rotors). When I did the brake job I checked for seized calipers, cleaned / re greased the slide pins and put new rotor retaining bolts. Since this noise started on Sunday, I have pulled everything apart looking for any signs of something rubbing on the brakes or tires but I can't find anything. Even checked the routing of the pad sensor wire.

The same day that I started hearing this noise is the same day the AWD and DSC malfunction error showed up. Scratching my head on this one.

I need some help on this one. I have done all of my own mechanical work for years (including engine rebuilds) but I haven't experienced this issue before.

cgeetaryan

I think I know what you're talking about. does it sound like a metal "clank" sound?

I think I have the same problem, well not really a problem according to certain individuals who'd explained to me.

The explanation was that your brake pads are slightly smaller than the "carriers" thus the loose gap allowing impacts to happen hence the sound.

my answer isn't very technical but hope it helps..

kenallwine

It is definitely not the pads "clanking". It is more of a "thump". (this is starting to sound like a commercial for AAMCO ).

The harder I press on the brakes, the louder the thump gets. It is rhythmic, so it is definitely rotational. Putting up on the lift tonight to see what I can find with the front drive axles... :thumbsdown:

seanjordan

I would take the caliper off and reset it. I have changed alot of brakes in my day and when I go too fast I dont set the caliper right. When the car drives you get that sound and if you drive too long on it will get worse and sound like it falling apart. If I am not mistaken that is your issue. I could be wrong. Let me know what you find out.

kenallwine

It looks like there is an issue with this lower guide pin seizing. It has all new grease in the sleeve and I polished it yesterday with no avail. It looks like it and the sleeve need replaced



It is the only thing I can guess. Everything else looks fine



I'm still looking around. For more

seanjordan

I think I read something on the guide pins seizing a few weeks back on Bavarians website if im now mistaken. They are selling some improved ones or something like that. I never had an issue so I read it and didnt think anything of it.

kenallwine

I'm trying to find that information now... I dont'want to have to replace the entire caliper...

seanjordan

Below is a screen shot of them.

CBUK Brake Caliper Bushing Upgrade Kit

$ 59.95



I cant find the article I read

kenallwine

Watching a few videos on these, it seems you have to keep up on maintenance on these brass versions.

I'm in a corner right now and can't wait for parts. I'm going to have to check with NAPA (I have a dealer account there) and see if I can get the bushing repair kit and new pins tomorrow morning or check with the two local BMW parts counters near by.

I truly appreciate the guidance. I hope this solves the issue.

seanjordan

Ok, well please let me know. are you putting the car back together and driving it tomorrow? Is the issue only on one side or both? I am going to do more research just so I know the real issue. One thing I found out is the oem bushings a not suppose the greased. That I didnt know. Ive been doing it for years. Well I hope you find it tomorrow and get it fixed.