Are you torquing them up properly? Did you get grease on the threads? You are supposed to grease them but not on the threads. Clean the threads on the pins and the carrier with brake cleaner and use a torque wrench to tighten them up to 35 Nm / 25 ft lbs

 

Ahhh, I hope that’s it. I’d been doing them hand tight, I’ll report back to see if 25ft lbs is enough tomorrow. Thank you

 

Strange, I have the opposite experience. The threads for the slide pins in my front caliper carriers were all stripped, yet everything would function as it should and they would never back out. Sounds like a very odd situation that you have - I was thinking maybe there is some weird vibration that could cause that, but the slide pin bushings should dampen all of that out

 

Strange, I have the opposite experience. The threads for the slide pins in my front caliper carriers were all stripped, yet everything would function as it should and they would never back out. Sounds like a very odd situation that you have - I was thinking maybe there is some weird vibration that could cause that, but the slide pin bushings should dampen all of that out

Why you didn't you replace the stripped pins? What if they fell out and you loose brake?
The caliper doesn't put load on the pin normally and this is why yours still working. But if the dust cap fell off then the pin will follow out too then disaster

 

I usually don’t grease them, just keep them clean and inspect for corrosion.
I have hit the guide pin surfaces with a light coat of silicone spray a few times before installing.

 

Definitely don't wanna use anything on the guide pins except silicone (if anything at all).

I found this out the hard way. I used caliper grease on the pins when I first bought my e46 and it turned into a black sticky tar within months!!

This is the silicone I use. I just can't accept keeping them dry. But BMW says so.

If you need some new guides and pins I have tons! When I ruined my first set I went the junkyard and grabbed a boatload. PM me and they're yours free, just pay for shipping.


Sent from my ONEPLUS A6000 using Tapatalk

 

Definitely don't wanna use anything on the guide pins except silicone (if anything at all).

I found this out the hard way. I used caliper grease on the pins when I first bought my e46 and it turned into a black sticky tar within months!!

This is the silicone I use. I just can't accept keeping them dry. But BMW says so.

If you need some new guides and pins I have tons! When I ruined my first set I went the junkyard and grabbed a boatload. PM me and they're yours free, just pay for shipping.


Sent from my ONEPLUS A6000 using Tapatalk

Thanks for all of the ideas. I’ve replaced pins/bolts, but thank you for the offer!!! I didn’t realize that there was a specific torque spec, I had been doing them just hand tight, so we’ll see how they hold up when I go out for a drive tomorrow.

 

I believe the calipers were installed incorrect, leading to caliper pushed a big load on the guide pin during braking. For front brake, the caliper wants to rotate up during braking but it is stopped by the carrier at the top rail. Look careful and make sure the caliper 4-point contacts are locked within the carrier rails, at top and at bottom. IF it was installed correctly, during braking the guide pin should have no load pushed on by the caliper.

 

They're a 'special fastener' not an 8.8. I too tighten them 'hand tight' but I guess I'm more heavy- handed

as I've seen what happens when the lower one comes loose on an E30 with 15" wheels going into
t2 at Spokanistan raceway...

t

 

When the slide pins back, its almost always due to a buildup of grease at the bottom of the hole. When too much grease is applied, it leaves little room for the pin at the bottom and it gets pushed back by the excess grease. Clean the pin and the hole out thoroughly and apply a light coat to the pin only. Should solve your problem.

 

This bolt won't back out so no worry, as the rubber holds the bolt quite tight and it won't turn by itself under any conditions.

 

^ What Mcar said ... this being brake hardware I find it hard to believe an extra 3 ft-lbs torque would be an issue. If any of this were aluminum, I could see it being more problematic.

 

This past week I was upgrading my brake pads and after putting everything back together, I went out for a drive and a few miles in I started to hear this terrible rattling that turns out to be due to my caliper guide pins backing themselves out a few threads.

When insert the pin into the hole, did you feel any friction from the rubber bushing? I have to push firmly to move the pin into the hole before threading it. With the normal friction of the rubber bushing I don't think the pin can back out this easy in a few miles driving even if it was not torqued down.