Rear discs

[robin121]

Hi I am trying to change the rear discs in my Audi Q7 2008  . Can anyone advise me what size tool I need to take off the rear Caliper 

[Magnet]

Hello Robin (from up the road),

I’m sorry I cannot help you and apologies for not being familiar with your model, but can I ask - does it have an electric handbrake, or the older mechanical one? 

Kind regards,

Gareth.

[robin121]

Hi Gareth thanks for   replying  to my comment its the manual one 

[Magnet]

Many thanks Robin,

Great. Apologies, but I get twitchy about working on the electric handbrake systems! 

Not sure what the set up is on yours, but if not obvious, the bolts can be ‘hidden’ under rubber blanking plugs. If so, they are generally 7mm recessed Allen key headed. If (in caps) this is correct you will of course need an Allen key socket since a normal Allen key is unlikely to shift it, but likely to cause damage to the bolt head! 

Sorry if all of this isn’t correct, and hopefully someone else will respond. 

Good luck and kind regards,

Gareth. 

[Bigdave1230]

I replaced my rear discs, pads and handbrake shoes about 2 months ago. The 2 bolts holding the calipers on are female multi spline bolts. Sorry I can’t tell you what size male tool you need but it’s quite big and has got more splines than a standard torx key and is unique to VAG. Honestly they are on that tight that if you don’t have that tool then don’t attempt it as you can’t get into it then with grips etc. My handbrake wasn’t very good so I bought handbrake shoes as I didn’t want to take the discs off to find I needed them. Turns out the shoe surface had broken away and was none existent (common problem because everybody just leaves them in park) so if your handbrake isn’t holding I’d recommend getting those too. Sorry I can’t say what size the tool is as I used a mates garage and used his tools 🛠 but google will probably tell you. Good luck

[Magnet]

Hello Robin,

Dave has come up with the answer, and if it’s not the conventional torx splines, but a ‘special’, then obviously it will mean buying the appropriate splined socket.

Would be worth nipping down to BMF - Bridgend Motor Factors - to see if they have this ‘VAG special’ size/ number of splines’ socket on stock, or could get it. Also worth looking in the Draper catalogue (non line?) to see if they list it. 

I would most certainly agree with Dave when he says don’t attempt this with anything other than the correct tool - bolts would have been put in with a Locktite type coating and can be reluctant to come out.

Kind regards,

Gareth. 

[Tommyb711]

Hey all! 
 

the bit your after is a XZN 16mm bit, they’re available online or on the bay of E. not too expensive either. 
 

but rightly said, no other tool fits and it’s tight! So be sure to have it before attempting

[GrimleyQ7]

Hi All

I need to change my rear discs too (along with new pads and periphery) and I have ordered said XZN 16mm bit (waiting for it to arrive) for the removal of the caliper bolts but I'm thinking of replacing the bolts with standard hex head flange bolts size M14x1.50x40mm, 10.9 hardness, high tensile.

Has anyone done this before?

Thanks in advance.

Chris.

[Magnet]

Why Chris? 

[GrimleyQ7]

Hi Magnet.

Just to make it easier to remove in future.

Those XZN head bolts seem bizarre to me and susceptible to rusting inside the splines, when a hex head will do the job just as well.

Was just a thought.

Thanks.

Chris.

[cliffcoggin]

I was about to suggest packing the splined hole with grease to prevent rust, but on reflection even a high temperature grease might melt and contaminate the pads.

[Magnet]

Thanks Chris,

Understand, but this is where the seller’s interpretation of ‘high tensile’ becomes the all important factor when using (probably made in China) replacements, - quotes of tensile strength may be questionable - and that is before we get into threaded and unthreaded lengths. 
If it were mine, I would stick with what you’ve got, or ideally buy replacements direct from VAG. Yes, I understand comparable prices, but would I want to find out HT replacements were not HT after all, and one of them parts company? No, too chancy. 
Kind regards,

Gareth. 

[GrimleyQ7]

Totally understandable.

Hopefully I can get the rears off ok without stripping the heads 🤞🏻

Thanks for your input.

Chris