Hi All,

I've been fitting new discs and pads all round, front both done but the rear is giving me a nightmare!

On the rear I've got as far as removing the part of the caliper holding the pads and now need to remove the caliper carrier. This is held on by two 14mm bolts which need to come off so I can then remove and replace the disc.

It's the two carrier bolts that are giving me the headache! I thought originally it was a star bolt (6 sides) and when that didn't fit on closer inspection I believed it to be a spline (12 sides). Having got some splines they still didn't fit it but there were splines with a slight difference in pattern in the local car spares shop, so probably typical I choose the wrong ones.

So does anyone know what these bolts are? Having googled for ages I'm currently thinking they could be XZN and I also see references to 'triple square bit' but I think this might just be another name for a 12 sided spline

Anyone got any experience on this?

Dougall

They may be Torx Star drive.

I think its a 14mm triple square bit that you need to remove the rear caliper carrier.

All the info you need is in this thread. http://www.golfmkv.net/blog/archives/5#

Thanks - just read through the guide.

So sounds like I need a 14mm triple square, which I now believe can also be called XZN.

Dougall

Also known as an m14 spline.

You'll also need a piston wind-back tool for the rears.

I bought a M14 spline made by "Laser" which didn't fit the caliper carrier bolts. If you compare the M14 spline in the shop against Drapers "XZN Spline" bits you can actually see a small difference in the shape.

For whatever reason Draper only sell up to 12mm XZN splines so looks like I'm going to get one from a company called Sealey who do a 14mm.

For future reference looking at the thread, a 12 sided spline is slightly different to a 12 sided XZN spline. Although you could probably 'make' a normal spline fit through force the caliper carrier bolts are in a tricky position to get any leverage so you really need a perfect fit as the bolts are supposed to be very stubborn to get off.

Dougall

I bought a M14 spline made by "Laser" which didn't fit the caliper carrier bolts. If you compare the M14 spline in the shop against Drapers "XZN Spline" bits you can actually see a small difference in the shape.

For whatever reason Draper only sell up to 12mm XZN splines so looks like I'm going to get one from a company called Sealey who do a 14mm.

For future reference looking at the thread, a 12 sided spline is slightly different to a 12 sided XZN spline. Although you could probably 'make' a normal spline fit through force the caliper carrier bolts are in a tricky position to get any leverage so you really need a perfect fit as the bolts are supposed to be very stubborn to get off.

Dougall

That's handy to know, I've bought all the stuff but not actually got round to replacing anything yet. Is it possible to test fit the spline bit I have without removing the rest of the caliper first or would it be inaccessible?

You don't need to take the carrier off on all the brakes, depending on size of disc a lot of them will pitch and slide out with the carrier in place.

if you took off one of rear wheels you could then get close enough to try the bit in the bolt. The incorrect spline kind of sits on the bolt and although you think it might fit it doesn't really go into the head of the bolt to give you the torque you'll need to shift it.

mine is held on with a bolt that comes off with a 7 0r 8mm allen key.

Also known as an m14 spline.

You'll also need a piston wind-back tool for the rears.

Do you not need one for the fronts then?

On the front the pistons push back in. On the rears the piston pushes back in whilst turning so it's near impossible without a wind-back tool.

Won't there still be a force acting on the piston that would mean you'd need a rewind tool to be able to push the piston back?

Edited 22 October, 201114 yr by j0hn

I used the rewind tool on the front and rear. I have in the past on previous cars changed the pads on the front without a tool. As long as you've taken the cap off of the brake fluid they will push back in using whatever you can make-shift as a tool to get a bit of mechanical advantage.

If you look at the pictures in this guide (http://www.golfmkv.n...log/archives/5#) you'll notice on the front he's used a big squeeze grip instead of a proper tool to get the piston retracted

I have to confess a big G-clamp normally does the trick for me!!

Thought you may like to know changing my pads yesterday I took off the caliper removed the screw holding onn the rotor to the hub. This enabled me to remove the rotor without removing anything else. Simple easy job.