Caliper bolts

[Doc007]

Does anyone have a source/specifications/link to an alternative source for the caliper bolts for a 2015 AP 2-pot caliper? I've just removed mine and it was really-bloody-tight for the whole of its extraction.

The Torx head was chewed up during its removal and I'd prefer a cap head or similar to replace it. The main issue is that the hole in the caliper is very tight with little room for a "shoulder".

I think this is the Caterham OE version. 
 

https://caterhamparts.co.uk/calipers-pads-discs/5294-caliper-mounting-bolt-to-ap-upright.html?search_query=Caliper+bolts&results=179

[Doc007]

Oh, and I think that part of the reason it was tight was the threadlock. How, do you clear out the threadlock from the thread before putting another bolt in.

[7 wonders of the world]

Run a tap down to clear the old threadlock

[Jonathan Kay]

There's quite a long discussion in the archives about the specification of this bolt. And a recommended replacement.

Please let us know if you can't find it. 

Jonathan 

[MTW]

Interested in a replacement too, I barely managed to get mine back in and torqued up they were so chewed up

[Wrightpayne]

https://caterhamparts.co.uk/calipers-pads-discs/5294-caliper-mounting-bolt-to-ap-upright.html?search_query=Caliper+bolts&results=179

[ScottR400D]

I had similar issues with the bolts on the 4 pots. One torx head was mullered and I needed to weld a nut to it to get it out.

IMO the issue is the OE thread lock. I replaced all the bolts with 12.9 cap heads and use Loctite 243. I did clear out the original stuff by running a tap down. No problems since. 

[Jonathan Kay]

The long thread (!).

Is this about the same type of calliper?

Jonathan

[ScottR400D]

I think that thread is mainly about the uprated 4 pot calipers JK, and this one is about the standard 2 pot (though perhaps not.......) 

 

[Jonathan Kay]

Thanks

Jonathan

[Gridgway]

I thought that running a tap in is always going to remove more metal from the threads which is not a good thing if it can be avoided.

[ECR]

No it won't remove more metal, just the crud in the threads. It's always crucial to make sure that the tap is properly engaged in the existing thread though.

[OldAndrewE]

If the tap is the correct one there is no reason why it should remove more metal (unless the thread in the hole is deformed or it is not started correctly).  It will remove dirt and debris from the thread

[PeterM]

If getting new bolts, cut/grind 2 or 3 grooves/slots in an old one and use it as a thread cleaner.

[Doc007]

I ran a tap down the holes. I honestly think I would have reached the torque figure before the bolt was home if I didn't. 

 Does anyone have guide for how to replace the discs?

In particular I need to know;

1. Caliper mounting bolts(x2) torque.

2. Disc to carrier bolts(x4) torque and how to hold the disc when tightening. Had to use a vice on the old disc without soft jaws as they didn't hold it tightly enough. Wouldn't want to do that on a new disc!

3. Torque for hub nut and technique. I understand it's very low (7nm???) +turning until next hole for castellated nut is aligned.

Thanks in advance.

[Nigel Riches]

A good soak with acetone or MEK, if you can get some, can soften most thread lock compounds.

Failing that the tap trick does it, it won't remove any metal provided you have the correct tap, or as previously mentioned take an old bolt of the same thread size and cut some grooves "UP" the thread with a triangular or half round file, this will scour out the thread lock goo.

If you try to run the bolt through the hole full of locking compound there is a good chance your torque figure will be reached prematurely, and therefore the bolt is not sufficiently tightened.

Good luck.

Nigel. 

PS Bin the Torx head or socket head screws and get some proper Hex headed bolts, I think the torque for the caliper mounting on 1982 car are 45 ft/lbs, not something for twee Torx sockets dealing with, Cap head bolts may stand this treatment, and I don't recall any mention of thread locking compound, so things must have changed over the years.

[Wrightpayne]

Re disc to hub bolts - just drop the assembly into an upturned wheel (making sure the nice face of the wheel won't get scratched on the ground)

[Doc007]

Thanks Wrightpayne!

That's just the trick I was looking for.

Now, does anyone have the torque values or know where I can get them?

[Jonathan Kay]

Have you already checked a text-rich Assembly Guide? (Not the new pictorial type.)

Jonathan

[Doc007]

The brake assembly comes as a pre-assembled unit so there are no details of the torque values for the bolts I'm using.

[SM25T]

When you put the hub into a wheel laid face down on the ground, grip it between your knees !

[Mark w]

Bin the torq head bolts and replace with Capheads . Namrick can supply a suitable replacement .

 

 

[Doctor]

I've used Allen head bolts in 12.9 tensile strength, the original TORX head ones are 10.9. Ro issues with clearance, easy to undo. Recommended.