You are counter-holding it at the collar, right?

You can try a nut extractor, the type that bites into the nut/bolt head and grips as it turns. Impact probably won't hurt here--even an impact driver with std. adapter would work.

This is the type of nut extractor I'm talking about:

Apart from that will probably need heat...using a torch is going to destroy the boots though so you'll probably be into a whole new set of pins/boots/bolts--they aren't anything super expensive though.

 

Yeah impacts not going to work unless I remove the whole caliper, I have the spline bits and a good long breaker but don’t fancy putting 200 or so nm through it on axle stands. There is no room to get anything mechanical on it, I tried it with a 1/2 socket and breaker but it wouldn’t fit. The real issue is not applying enough torque, it’s just that it needs more torque than the nut will take. Maybe the bottom bolt just picks up more road muck than the top one because it’s seized in pretty good. Only option now is to cut it.

 

I'm confused now the 200N*m bolts are the M14 triple squares holding the caliper bracket/carrier to the car... I thought you're having a problem with the slider bolt on the caliper and not those bolts? I get it's seized but 200N*m would likely snap the small slider bolts.

As you say though torque isn't the issue, it's the rounded head I imagine--the bolt biter extractors work fairly well to deal with those IME, but you could also use a grinding tool (Dremel, etc.) to cut the head off if that works. Dremel will take a long time to get through though and a larger grinder (die or angle) may not fit very well.

 

Yes sorry. The evil ones are the 14mm slide bolts, I meant that to get at them to use an impact or to cut them I would have to remove the entire caliper, which are the M14s and 200nm is a bit dodgy on a car on jack stands. May have to put my big boy pants on.

I have nut extractors on the way but they seem to be designed for impact tools, will they be fine on a ratchet or breaker bar or do they need to really bite in?

 

Oh okay I get it I think, you want to pull the entire thing bracket/carrier and all, if you can't get the slider bolt out. So in that case you need to get the carrier bolts off. I'm curious though why are the calipers coming off to begin with? Typically they'd be removed for a brake job but that's not really sounding like the case here? Maybe you have a sticking caliper or were you just replacing pads or something... Anyway,

I have nut extractors on the way but they seem to be designed for impact tools, will they be fine on a ratchet or breaker bar or do they need to really bite in?

They will work on a standard ratchet or breaker, yeah. They are typically just impact rated tools so you can use them with impact. Impact works differently to constant/linear torsion hand tools and is less likely to round nut/bolt heads to begin with, but used with the bolt biter sockets, less difference in that regard I guess...unless you have a really soft bolt head. Low-power impact is still likely to make it less of a headache IME (that's why I said maybe an impact driver if you have one, on a low setting), but in the absence of that I'd go ahead and use the sockets with a regular ratchet and see if that yields success.

I'm wondering if the bolts on the car are aftermarket given the cheese like nature of them lol. Maybe replace them with genuine OE ones after you get them out. The originals are probably Dacromet coated and have the threadlocker "pre-applied" on them...wondering also if the bolts on the car were reused at some point and perhaps the person installed them with too strong a threadlocker, making them difficult to get out now. Or could simply be corrosion as you say.

 

The 13mm slider bolts are set at 35Nm. Theoretically, that’s not tight. Some vendors sell these bolts with a innner TORX head. I think it’s a T30. Have you checked the head? Have you tried vice grip pliers? You could also try using a Dremel tool to smooth the sides of the head for removal.

 

The above is correct. You could also Dremel a slot for a thick flat head screwdriver bit to try.

 

Was aware the carrier bolts were low torque, but obviously they have been changed and the previous monkey didn’t get the memo. The job was rear pads and disks, but was hoping to get away without removing the caliper due to the difficulty, out of all the research I've done the field is split pretty much 50/50 on whether or not you can get the disks in without taking off the carrier, they are pretty big disks and vented so pretty thick. If I can do it without removing the carrier it’ll save me a lot of time, stress and knuckle skin. I did front and rear pads on my previous TTS and front ones on this, came to the rears and got completely sideswiped by a cheap ass Swiss cheese bolt.

The new pads (Brembos) come with new shims and new bolts, which do have pre-applied blue threadlock, while the old ones (got the top one out ok) do not look great, so yeah I think they were reused.

 

You're definitely not getting the rotors off without taking the bracket off on an S. I think it's only the lower size rotors you can do that with and I'm not even sure if any exist on the TT that this can be done with (there are several different size rears but the TT might only have one or two different ones of those, but then since over there you have the 1.8T maybe more there than here). In any case I just don't see it at all possible on an S model with the 310mm rears. They are both significantly larger than the lower brake options and they are vented so much thicker, as you say.

In that case go ahead and remove the triple squares and see if you can just take "the whole thing off", then deal with the busted up slider bolt when you have the whole thing out of the car.

 

You're definitely not getting the rotors off without taking the bracket off on an S. I think it's only the lower size rotors you can do that with and I'm not even sure if any exist on the TT that this can be done with (there are several different size rears but the TT might only have one or two different ones of those, but then since over there you have the 1.8T maybe more there than here). In any case I just don't see it at all possible on an S model with the 310mm rears. They are both significantly larger than the lower brake options and they are vented so much thicker, as you say.

In that case go ahead and remove the triple squares and see if you can just take "the whole thing off", then deal with the busted up slider bolt when you have the whole thing out of the car.

Looking at it I would absolutely agree, but some say you can, some say you can’t, thought it was worth a punt. Maybe although the disk is larger the caliper is too so it goes in, either way in the videos I’ve seen, it’s damn tight.

Pretty much moot now as the bolt extractors did bite, but just wouldn't turn the nut so I reckon it’s a combination of over-torqued, additional threadlock and corrosion/muck and dirt. I gave the caliper bolts a go but the only way to get a bar long enough to put sufficient torque on them is from below, so the car needs to be on a lift, so it will have to go in somewhere.

Absolutely fuming that I have to give my car to someone else to do just for the sake of one bolt that someone couldn’t be arsed to do up properly, probably the same guy that fitted the wheels before I bought the car and torqued the wheel nuts to about 350nm.

 

Torque happy numpties, I’d line ‘em all up and shoot ‘em if possible. Tyre shops seem to be the worst, but garages can be just as bad. I don’t know if I was doing right from wrong, or maybe insulting the mechanics who did my rear brakes, but I specifically gave them the correct torque values in a hope they pay a little bit of attention to them. The tyre shops seem I used certainly didn’t as the wheels had to be whacked off with a rubber mallet after they’d put them on before the disc/pad change.

From what I’ve learned, it’s nigh on impossible to swap out 310mm rear discs/rotors with the “slide ‘em in” method without doing the carrier.

 

I have managed to do rears without removing the carriers, at a certain point they just pop in but its not like a straight in and out with clearance.

 

So coming up to mot time it was necessary to revisit this. The seized slide pin bolt is still seized but having conquered the impossible carrier bolts I didn't need to get it out anyway.

The issue was being able to get enough torque to the carrier bolts without knocking the car off axle stands, the plan was to reverse onto my ramps which should give me a stable enough platform to break the torque, then roll the car off the ramps, finish them off by hand and swap the pads and discs as normal.

Absolutely the only way to get any meaningful access to the carrier bolts is from below, and the upper one is particularly hard to get at but it turns out the 200nm of torque required isn’t all that bad. I used a retired torque wrench just because my breaker bar was too long and my ratchet was too short, once the torque was broken i switched to the ratchet until I could turn the bolts by hand. The issue with the upper bolt is getting the bit and a ratchet head into it, to the point where even if you do get in you can't ratchet it all the way out because there simply isn't enough clearance. I ended up using a sliding t bar, removing and rotating the spline bit, turning it about 1/8 turn at a time until it was finger loose, very time consuming as the bolts are about 3 inches long, but once they’re free you can do most of the work by hand.

Once that was done and the car was off the ramps the rest of the job was pretty standard, carrier bolts came out easily and gave full access to change the discs, remove the slide pin bolts and put in the new pads. The chewed up bolt remains, I did have a go at it with a bolt remover on my impact gun but it wasn’t having it and as it was no longer necessary to remove it I didn’t want to make it any worse. Once everything else was done I put the car back on the ramps to give the carrier bolts a final torque and I’ll check them again next week after everything has had a chance to bed in.

The carrier definitely has to be removed to get new discs on and it does make the rest of the job a lot easier too, and with a bit of perseverance those 200nm bolts aren’t anywhere near as bad as I thought they’d be. Hope this helps anyone else planning the same job.