My 256 vauxhall calipers only have 2 copper washers on the bonjo bolt to seal them. Tbh I see no reason why a copper washer wouldn't seal it just fine, after all that's what they are designed to do. you could always use a grinder to shape the end so it suits the caliper

Edited 26 June, 201214 yr by Mclovin

@keerly - I should use the mk iv calipers if you have them. Seem to be less problems

I was joking about PTFE lol, so technically good ridge are making the wrong lines? But anyway I'll go with the copper washer, I can't see it being a problem

I'm not sure. I can only think that there were some revisions to the caliper design at some point, or maybe there is an adapter in there from some where?

Go for the copper washer, but make sure its a nice fit around the cynlindircal part of the fitting. Some of the ones I had were a little loose, and when tightented, the hole of the washer didn't seal around the machined head. Your's looks fine though. Also, I found that as i tightened the head dug into the washer, altering the shape and again, failing to make a seal. The banjos don't suffer from this as the head is 'round' (without the angles of the bolt head).

Takes Safs advise though as it seems sound, just try it and regularly test for leaks in the system in the first week or two