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 (https://www.screwfix.com/p/laser-mixed-crow-s-foot-wrench-set-10-pcs/7488f). 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