Caliper Bolts

[Furchester]

Hello,

I'm in the process of replacing my front calipers and after much debate and head scratching I have a set of Imperial 16P calipers. I found my old bolts had a flared step in the shaft which prevented them from passing through the caliper and into the hub bracket.

After getting in touch with Rimmer they advised that I should use Imperial Caliper bolt 113142. They turned up today and I was keen to try them out. They seemed to wind in OK but they're about 1cm too long 😲 ... meaning they foul the discs when tightened all the way up.

I am waiting on a reply from Rimmer but was interested to see if anyone else has had this problem?

On the website the part is described as 'Bolt - Imperial Short - Caliper Mounting' with the above part number but the bag they arrived in only says CALIPER BOLT - IMPERIAL. The same part number is listed on the bag.

Cheers

[Nick Jones]

What car?  Assume late GT6 Mk3?

I think those would have had M16 calipers originally (although possibly they have have been fitted later), which would have needed the (slightly) stepped bolts.  The imperial calipers should be a straight swap apart from the bolts and pipe union so it sounds like the bolts are just too long.  Provided the caliper sits centrally over the disc and the unthreaded section of the bolt is a snug fit in the caliper hole and short enough to allow it to be tightened without bottoming, then you could just chop the extra off leaving just a couple of threads through.

Still worth telling Rimmers they are wrong though - or they'll keep selling them!

Nick

[Furchester]

Thanks for the reply - yes apologies it's a '72 GT6 MK3. The calipers appear to sit centrally and all looks good except for the length of the bolts! I may cut them down if I have to but would rather have the right ones. Very frustrating.

[Chambers]

Out of interest, what have you torqued the caliper bolts up to?

[efp]

Quoted from Furchester

I think may cut them down if I have to but would rather have the right ones. Very frustrating.

Would just suggest that before cutting them down, check that as much threaded length as possible is within the calliper. I had to take a die to extend the thread back into the plain shank of mine after trimming to length.  Another alternative if a few more washers under the bolt head. In any event, I’d suggest a dab of thread lock whatever the torque setting. The threaded depth isn’t huge and you really don’t want them coming loose.