Help / advice removing rear brake caliper carrier Audi A4 B6 2004

[Domdom]

Possible one for @premmington but hopefully others as well.

My trusty Audi A4 needs rear discs and pads. No biggie for me usually, but I’ve come across a fairly bad design.

To get the rear discs off needs the caliper carrier bracket removing which is quite normal. To unbolt it is anything except normal though. The bolts, which go in from behind, they’re 8mm Allen heads and look impossible to get to without removing the entire suspension/hub assembly and putting it in a vice. I can get to the upper bolt if I remove the shock absorber but the lower one is pretty much inaccessible. Needless to say the one I could get to is super tight. I tried my Makita 1/2” drive impact, nada. Then a breaker bar which snapped the Allen key socket (US Pro tool)

I’m not keen to remove it all as that means a 4 wheel alignment afterwards. So I soaked them in penetrating fluid yesterday and will do again today. Can’t easily get the bolts hot as there are rubber bits nearby.

Any other ideas chaps?

And, where can I order a 1/2” drive 8mm short Allen key for delivery to a UK address before Friday. Needs to be better quality than the US Pro (swiss cheese) things please. Mrs DomDom can bring it over next weekend.

 

[RWD3M]

You could sacrifice a regular Allen key by cutting a short length of it to insert into the bolt then try and 8mm ring spanner to undo it?

 

[Endeleus]

I spent about 4 successive weekends doing the brakes on my A4 B7 a couple of years ago, after it had sat for around 5 years. As I recall, it was just possible to squeeze the rear discs out and in with the caliper bracket in place with a bit of fettling, but the fronts took me several cycles of plus gas, heating and 2 bent breaker bars to get the caliper bracket off.

 

[Endeleus]

 

[8ob]

And, where can I order a 1/2” drive 8mm short Allen key for delivery to a UK address before Friday. Needs to be better quality than the US Pro (swiss cheese) things please. Mrs DomDom can bring it over next weekend.

Have a look at the draper range of specialist bit drivers, they are very good. Not to be confused with the other gear they make.

Draper Expert Brake Pad Key with Handle, 8mm

Established in 1919, Draper Tools is a supplier of quality trade, professional and diy tools. Check out the massive range of tools available from one supplier.

www.drapertools.com

Bob

 

[Domdom]

I spent about 4 successive weekends doing the brakes on my A4 B7 a couple of years ago, after it had sat for around 5 years. As I recall, it was just possible to squeeze the rear discs out and in with the caliper bracket in place with a bit of fettling, but the fronts took me several cycles of plus gas, heating and 2 bent breaker bars to get the caliper bracket off.

I watched that last night. 35 newton metres my fat a**e.

I did try the fettling but it’s not possible. Yes, I could get the old discs off with a bit of brutality but getting the replacements in without damaging them is not possible.

 

[Migmac]

Pretty sure the youngest grease monkey in our family fitted new discs on my daughters Audi without removing the brackets

 

[zzr1200]

Have you tried heating the lug the allen bolt screws into to melt the studlock before removing the the bolt?

 

[Domdom]

Pretty sure the youngest grease monkey in our family fitted new discs on my daughters Audi without removing the brackets

Many sources say it should be possible but equally many say it’s not. I can confirm the latter, at least on my car.

Have you tried heating the lug the allen bolt screws into to melt the studlock before removing the the bolt?

No, there’s too much rubber around. To do that would need an induction heater, which I don’t have.

 

[Blobber]

Did you want a Haynes manual? Got a really nice one you have for the cost of posting

 

[Endeleus]

Many sources say it should be possible but equally many say it’s not. I can confirm the latter, at least on my car.

Similar experience, however once I'd got the originals off, then it was easier to convince myself that the new ones would go back in the same way.

I definitely knocked the rust off the outside of the old discs, then still needed a fair amount of brute force, which is fine on the removal stage.

I'm pretty sure I took the edge off the brackets with a hand file to make it easier to fit the new ones - barely 0.5mm made all the difference.

 

[Jack Pattenden]

Possible one for @premmington but hopefully others as well.

My trusty Audi A4 needs rear discs and pads. No biggie for me usually, but I’ve come across a fairly bad design.

To get the rear discs off needs the caliper carrier bracket removing which is quite normal. To unbolt it is anything except normal though. The bolts, which go in from behind, they’re 8mm Allen heads and look impossible to get to without removing the entire suspension/hub assembly and putting it in a vice. I can get to the upper bolt if I remove the shock absorber but the lower one is pretty much inaccessible. Needless to say the one I could get to is super tight. I tried my Makita 1/2” drive impact, nada. Then a breaker bar which snapped the Allen key socket (US Pro tool)

I’m not keen to remove it all as that means a 4 wheel alignment afterwards. So I soaked them in penetrating fluid yesterday and will do again today. Can’t easily get the bolts hot as there are rubber bits nearby.

Any other ideas chaps?

And, where can I order a 1/2” drive 8mm short Allen key for delivery to a UK address before Friday. Needs to be better quality than the US Pro (swiss cheese) things please. Mrs DomDom can bring it over next weekend.

If a 1/2" impact and a breaker bar didn't do it, it might be a 'it can't be stuck if it's liquid' kind of situation - except you can't get it hot.

If the pen oil doesn't help, do you have the means to cut the head off the bolt and extract / drill it out? A bolt extractor tool might be a worthwhile purchase?

My Makita DTW700 has thankfully handled everything thrown at it so far, but did require full power for a couple of really nasty stuck nuts and bolts. If yours has less muscle, this might be an excuse to upgrade?

Jack

 

[anto44]

I'm pretty sure I took the edge off the brackets with a hand file to make it easier to fit the new ones - barely 0.5mm made all the difference.

I worked for audi and vw for years, follow the advice above, removing the caliper carriers on these is a world of pain that you don't want to get into if you can avoid it. Those bolts will be very tight with a very high chance that they'll round off.

 

[daedalusminos]

I would double check you need to remove the carrier, sometimes the hubs are not circular and rotating to the correct position will allow disc removal.

Edit: rust build up will also give the impression they're not coming off....if it's that close they're probably designed to come off with carrier insitu

 

[frank horton]

German enginerrrrrrring again..
much prefer their older cars...

 

[roblane65]

I did this job many moons ago on me old s-line IIRC i butchered a decent quality long 8mm allen key , cut down the short end to a stub and used a suitable length of fairly heavy tube over the long end for leverage . The only reason I did the job was I was uprating to slightly bigger discs so I needed to change the carriers anyway