[Youds]

Hi Guys,

I don't know if this is normal or not as it certainly does not seem to be a normal thing. Either way, recently did my brakes and noticed before I put the wheel on that I could move the caliper around a bit (both sides). Put the wheels on, pumped brakes etc. and have driven for a while. I notice that I can still reach through the rim, apply some pressure, and push the caliper towards the back of the car 1/8th of an inch or so. This does not happen with the rears. This can't be normal can it? If not, what would cause it? Any answers would be great and if anyone is bored and wants to go out and try on theirs, have at er!

[WatchWolf34]

Did you reinstall the thin metal clip that goes on the front of the caliper? The caliper will have some movement in it if you leave that off...

[SpartaEvolution]

EDIT: BIG THANKS to @freedomfries for posting the correct pictures below. It turns out that this sliding caliper design is not the same as what I had in mind. The red and blue sections are one piece, and that piece is floating, as such it should both have *very small* amounts of play when everything is installed and torqued correctly. Sorry for the confusion!

The following italicized info is wrong:
So long as the carrier isn't moving (blue section in picture) then that is fine. Sliding calipers have a carrier piece (blue) and sliding piece (red). The carrier is bolted directly to the knuckle, and the sliding piece is bolted to the carrier via guide pins, but the pins are only secured using rubber bushings, so there will be a certain amount of flex allowed.

A couple vendors here sell brass bushings which will eliminate this flex, but brass bushings need to be lubricated and generally require a bit more maintenance, so they aren't ideal for our PNW fall / winter / spring seasons.

[WatchWolf34]

I still think that based on what he is describing his problem is that small metal clip - flat face with a hole in it that is shown in your picture - within the red circle

[Youds]

Ya the blue thing is moving...thoughts?

[WatchWolf34]

I stand corrected then! There are only two bolts holding that to the knuckle - if it's only slightly moving perhaps they didn't get tightened down all the way?

[Navy Doc]

Originally Posted by Youds

Ya the blue thing is moving...thoughts?

That should not move at all. I would get back in there and check the mounting bolts. Maybe not tightened down all the way.

[SpartaEvolution]

The two bolts on the back of the blue piece (carrier) should be torqued to 81 ft-lbs for the front, and just for the record 50 ft-lb in the rear.

[MysticRob]

Originally Posted by SpartaEvolution

The two bolts on the back of the blue piece (carrier) should be torqued to 81 ft-lbs for the front, and just for the record 50 ft-lb in the rear.

I'll be the first to thank you for that info.

[juld0zer]

Rear bolts are supposed to be replaced due to the threadlock compound applied at the factory. Be careful doing them up if you reuse them

OP, do you have the clips fitted? Or did the car not come with any clips?

[Youds]

Should I be using any threadlocker on the fronts?

Yep, clips are on.

Out of town but will see if bolts are loose when I'm back. Must have not tightened enough and then they loosened more. Thanks for the help!

[SpartaEvolution]

We never use loctite/antiseize on our race or street cars, and we've never had an issue.

[Youds]

Looking at it, that diagram is a bit off. It's only the top and bottom of red that are fixed. The rest is all caliper. The fixed part doesn't move, caliper does a bit but was told it is normal.

[Meeni]

Originally Posted by Youds

Ya the blue thing is moving...thoughts?

You need to retorque the carrier. Given that it's a safety issue, remove it completely, inspect the threads, and reassemble per-the-manual with the proper torques.

If you are not confortable, don't guess and seek professional help.

[Youds]

The blue thing being the caliper which others have stated in this thread is normal due to bushings on the guide pins. The actual mounting bracket is stable.

[Meeni]

No the blue thing is the carrier and it should not move -at all-. The red thing is the caliper and is semi-floating and should have some amount of play.

[Youds]

The blue and red are attached. The carrier does not move and is beneath the caliper.

http://m.autozone.com/brakes-and-tra...2362?location=

As shown on that site, the carrier is the dark part and is separate from the caliper. Calipers are huge on this car.

[Efthreeoh]

Originally Posted by Youds

The blue and red are attached. The carrier does not move and is beneath the caliper.

http://m.autozone.com/brakes-and-tra...2362?location=

As shown on that site, the carrier is the dark part and is separate from the caliper. Calipers are huge on this car.

Okay, you are mistaken and are giving incorrect and dangerous information. In the pic posted above, the part traced in blue is the brake carrier bracket, which is affixed to the wheel hub with bolts. The carrier bracket does not move once the bolts are properly torqued. The bolts are reusable and do not need locktite.

The part in the pic that is traced in red is the caliper, which floats on steel pins that thread into the carrier bracket. The pins sit in hard plastic bushings that can allow for a minute amount of play fore and aft, but moving the caliper by hand through the spoke of the wheel should not be possible (unless the OP is an ape).

In the Advanced Auto link you posted, the "dark part" at the bottom of the series of pics of the caliper is the anti-rattle spring clip, ; it is not the carrier bracket.

OP, you should not be able to move the caliper if the wheel is on reaching through the spokes. The caliper can move inward towards the car and outward toward the wheel, but that movement is very slight and would still be difficult to accomplish by hand. If the brake on your car is moving as you say it is, then it is not installed correctly. The carrier bracket bolts sit in through-holes in the hub and thread into the bracket, so they could be loose and allowing the carrier bracket to move as you describe, but this is a very dangerous situation and needs to be corrected immediately.

[juld0zer]

On this particular caliper, the spring/clip is very strong and does require a decent effort to wiggle the caliper - compared to doing the same with a 320i or 325i caliper.

[Youds]

Alright, I feel like like we need some further evidence of what I am saying in terms of Blue and Red being the same. Please see the pics below:

View post on imgur.com

As you can see, the "Blue" and "Red" parts are all one piece and features a piston that, when brakes are applied, pushes the pads on to the rotor to stop the car (ie. a caliper). How am I wrong in this regard? That whole piece is secured only by two guide pins which connect to the mounting bracket (or carrier unless I am completely wrong there). The bracket is connected to the hub with two bolts.

Am I right here or have I started to drift off in to old age?

Either way, the caliper moves slightly which was explained above as somewhat normal due to the bushings. I have checked the torque on all applicable bolts.

Sorry if this comes off a bit rude, hearing that I am dangerously wrong is not the best thing to wake up to haha Hopefully it is just a misunderstanding rather than I may die today.

[The Nightman]

Originally Posted by Youds

Looking at it, that diagram is a bit off. It's only the top and bottom of red that are fixed. The rest is all caliper. The fixed part doesn't move, caliper does a bit but was told it is normal.

This is correct.

Caliper:


Bracket:


Together:


Assembled:

[Chappers 71]

The 335 has 'floating' calipers, a bit of movement is normal.