Bolt size for bontrager caliper direct mount?

[jxblackhole]

I am trying to get confirmation of the the bolt size for bontrager (trek) direct mount caliper - the main bolt. On my edmonda (1.5 year old) the bolt heads are starting to rust and it is aesthetically unpleasant. Thanks

 

[King Boonen]

Shimano have two lengths, 9.2 and 7.5mm. You'd have to take them out to know which was used as it's dependent on the frame (or ask Trek/a friendly Trek dealer). I don't know if the brakes come with both, might be worth asking an LBS if they have any spares. Pretty sure all Shimano DM calipers are 4mm hex key, afraid I don't know about other brands.

 

[jxblackhole]

Thanks for that. I was simply hoping for a quick answer before either I dismantle the caliper or take the my to my LBS (already asked but have no clue as nothing in the shop and yet they are a bontrager/trek re-seller!). It looks like I'll have to do it before ordering new the fasteners