Allen key sizes???

If its smaller than a 5mm bigger than a 4mmm and 3/16 what size is it???

It’s the retaining ‘piston and guts’ grub screw on the rear caliper.

Sorry for starting a new thread but thought more would see it.



If its smaller than a 5mm bigger than a 4mmm and 3/16 what size is it???

tempted to say 4.5mm…but that would not be very helpful would it?

absolutely - but never seen them in half mil steps???

I was hinting that it might be a brembo special but they couldnt be that tight surely

Cant find a 4.5 ont tinterweb and next up from a 3/16 is 7/32 and by my recknin thats 5.5 mm ish

are you sure that the socket to receive the allen key is totally clean and free from any surface corrosion that just maybe stopping the right key fitting. It can be quite difficult to clean completely at that size…have you tried a wire brush?

Alternatively, you could grind down the larger size one to make a bespoke one. Allen keys are quite cheap down the market - just don’t ruin your best set!

i cleaned it out best i could 5mm is miles to big and the 4mm would spin in the hole if i forced it.

Going to drop into the local garage see if he has anything to fit.

I think I will then refer to a specialist b4 I do any more damage

I think I will then refer to a specialist b4 I do any more damage

Let Russ sort it for you tonight @ The Buckles.

Not a cat in hell’s chance

Simon, 4.5mm does exist. Have certainly used them on my pushbikes. Would either try Maplin (though quality may not be great), give your local cycle shop a ring or if you are really struggling I will have a route around the garage this week and if I find one could put it in the post.

when I googled it lots of bike stuff came up but couldnt see a specific size - back to halfrauds then!

and Pesky - Russ wont mind me bruising his new aston toolkit with a rust old caliper will he

Don’t bother with Halfords, just go to a decent independent bike shop, they may well not have them for sale but will have one in the workshop. Ask them nicely, leave a deposit and they will let you borrow one. No chance of Halfords providing the same level of service…

Also Maplin have them in a set of 25 for a fiver.
Treat them gently though

Thanks Steve theres a Maplin down the road - I think they might be ‘heavey duty’ - with tongue in cheek!!!

Also was steered to these guys who are supplying a new seal kit - which contains all the seals - even the ones mere mortals cant replace?? (I need new slider dust boots anyway) and its only �20 for each caliper.

They also do brakes for other stuff - Am sending my Elan handbrake pads to them for relining - two birds with one stone.

Wow that does make one feel like one is running a classic when one has to have stuff relined!


do they also have the piston seal ? (for a rear caliper)

I tried to get a rear piston seal for ages… no one i went to could do it… the slides and other bits seemed easy but the piston seal wasn’t available.

apparently the kit has ‘everything’ in it. I think it even has the seals for the handbrake shaft? He was sending it yesterday so when it arrives I will let you know.

oh yeh the Malpin allen key now looks like this


I’ve had my brembo’s apart to powder coat them and it is indeed a 4.5mm

Catalog page 2707

thanks fella - it’s off down to the local engineering place in the morning. He’s a dry old sod who runs a V8 powered Excel - I’m hoping he can sort it before I bugger it up completely

Hi Rox - this is whats in the kit - sorry photo is a bit Tom Tit.

Delivered next day �26 all in. Even includes a new steel slider and grease!


PS Engineers got the stop bolt out this morning

the big concertina seal looks like it could be the piston seal

Does he have a part number or order code ? or do I just call him up and ask for an exige rear caliper seal kit ??

hey up - that one is the piston dust boot. The big one bottom left is the main piston seal.

The whole lot comes as a kit - I only needed one of the slider dust boots but I might as well do the lot while its apart.

Just tell him its exige elise brembo rear like they just sent to me! Simon Hudds address

For info - I got two kits for the Mister 2 rears and that lot came to �70 (from toyota - trousers down or what!)

Collecting the caliper tomorrow for disembly shinanigins

Also sent them a full set of the Elan Sprint handbrake pads to reline


let us know tommorrow if it all fits properly