Front Brake Caliper Loose - could it be caused by other work?

[eddomak]

My D4 had a problem today. Upon braking there was a loud rattle from the passenger side and strange brake pedal feel. Stopped the car, and there was nothing underneath to cause it. Then I noticed the caliper shift. Upon comparison to the driver's side, it looks as though there is no clearance between the wheel and the caliper, which makes me think the caliper has come loose.

Needless to say I am waiting for roadside assistance now.

Could this have possibly been caused by the recent job to replace the front control arms, or the subsequent job of having a full wheel alignment?

Assuming they can't fix it at the roadside, I would like to get it taken back to the place I got the front control arms done, and would like to see if it is something they may have caused.

From what I see on YouTube, calipers do not need to be loosened/removed to do the control arms on a D3, but I have no real experience of my own. Also I don't want to blame people unnecessarily.

[Graeme]

Unless a bolt has fallen out, the 2 bolts should be able to be re-torqued, although they're meant to have thread-locker so would need to be removed to apply it. The torque required is quite high - I had to use an extension to get enough leverage to undo mine.

from the WSM: 275 Nm / 202 lb ft

Certainly not required to be undone for a wheel alignment.

[eddomak]

NRMA had come and indeed found loose bolt and removed by hand. The calliper has scraped and damaged inside of the wheel rim.





Just very grateful that no one was hurt in this dangerous situation.

The car will be towed tomorrow morning to the same place that did the arms for their inspection, rectification, and see what we can do about the damages to the wheel.

Thanks Graeme for the reply about torque and locktite. But is it absolutely necessary to remove the caliper to perform the arm change?

[justinc]

Loctite always. Yes they are supposed to be tight. No you don't normally have to remove the caliper to replace arms only undo the driveshaft nut to allow the shaft to be slid out to pop the arm up out of the lower ball joint taper. Some may remove caliper but i don't.

Jc

[Graeme]

Whether its absolutely necessary or not to remove the caliper bracket is not the issue, its that it appears that no thread-locker was used when refitting the bolts that have been removed for some reason. Have the discs ever been replaced? The bracket is normally removed to replace discs.

[isuzurover]

I have never seen those bolts come undone even without loctite. I would place money that your mechanic forgot to do them up.

[eddomak]

I guess my question boils down to "Who was the last person to touch those bolts?"

If it is absolutely necessary to remove the calipers when doing the front arms, then the last person to touch it must have been that mechanic (2 weeks ago).

If it is not absolutely necessary, then it is could be that mechanic, or it could be the one who changed my brake pads/rotors back in July.

[GlennS]

Hi Eddomak, when this is sorted could you tell us who was at fault ?

Cheers,
Glenn

[eddomak]

I'm glad to report that this has now been fixed. The bolt was replaced with locktite, and all other brake callipers were also checked. Unfortunately the other front calliper bolts were also far too loose (and now tightened).

All strange noises have now stopped, including some minor rattles which I had assumed were suspension bushes.

The conclusion is that it can never be certain. The last mechanic who did the control arms said he didn't touch the brakes as it isn't necessary to do so. I believe him as he is a very honest guy with integrity.

I will report it back to the one who changed over the brakes in July, but not as an accusation, just for them to keep an eye out.

Just thankful that this has all been fixed speedily and no one has been hurt, and I have been impressed again by another person's helpfulness.