Audi A3 Rear Brake Pads - difficultly getting caliper removed

[malt56]

Hi Looking for help - I am trying to replace the rear pads - according to Haynes manual - says use spanners to unlock the bolts - tried soaking bolts with wd40 and then attempted to break with a 13mm spanner - bolt either rusted on or over-torqued - spanner keeps slipping and getting rounded points on the bolt. Purchased a 13mm impact socket ( my multipoint sockets slipping as per spanner) - however there is not enough space to get my socket and a ratchet onto the bolt - ideally I would need a low profile 6 point 13mm socket & 3/8" drive ratchet - approx 4cm of space to play in for ratchet/socket). Any other tool suggestions which would make this easier ?

[jonathanfenton]

Some calliper bolts come with a ridiculous amount of threadlock on then added in over torque and you’re in for a fun ride. I have a teng 3/8’s set with a swivel head which I have used to get me some leverage on them. Some heat and a hammer, innotec make some serious penetrating oil called debloc which is really good. Failing that you’re at the Chuck it at a garage to change them for you so you can do it next time.

[Crasher]

The book torque is, for an M8, a rather surprising 35Nm and the screws are thread lock treated from the factory; they must be replaced and quality pads come with the new screws treated with thread lock.

[VAG-Abound]

PlusGas is my penetrating fluid of choice. Hard to say it works better than WD40 on a specific bolt as I never know what WD40 might have done .

The flatness of a decent quality 12" adjustable spanner has helped me at times. Able to slip into narrow spaces. Adjust jaws while wiggling it a bit to ensure best fit. Offset ring spanner or crow's foot spanner come to mind as well, like this set at Screwfix. Will fit breaker bar or socket ratchet, at risk of snapping ratchet on latter of course with a corroded tight bolt. Cut off box spanner maybe. Nice set of six sides, but tend to be a bit soft. A friendly local workshop could weld a flat arm to the top of it to keep it compact.

I've used an empty veg can as a nozzle guide for my hot air gun to allow moderate heat to be focused, which has helped when I'm unwilling to use blow torch.

[Roverfan]

Try 1/2" spanner. It is between 12mm and 13mm. Wouldn't be surprised if it was a 1/2 inch bolt used. Some parts of the world prefer these fractional sizes over metric

[Crasher]

Yes, no VW mechanics tool box is complete without a 3/8" and 1/2" six sided... 1/2" socket.

[malt56]

One last spin of the wheel before I try/retry previous suggestions - just ordered a 3/8" 13mm low profile impact socket - which if my research is correct should allow enough room to use ratchet to try and free off the bolts

[malt56]

Low profile socket did not work - eventually had to relent and put to garage to free up calipers - however now got 2 more issues which I have moved to a new thread