A friend of mine has finally give up on his Avid rear set up and bought a Shimano brake set to replace it. However he is a leftie and runs his brakes Euro style but bought a normal rear hoping to swop hoses. Am I right in saying Avid m/cylinder won’t work with a Shimano calliper and vice versa ?
I think the only thing he can do is buy a front Shimano set as well. Your wisdom appreciated

One uses DOT,one uses mineral.
The seals are specific to each type of oil.

They wont work and they use different types of fluid, so even trying will kill the caliper
Shimano system use mineral oil
Avid systems use DOT fluid

probably wont be great from a mistmatched hydraulic point of view but what fluid does the Avid use? Dot 4?

Shimano use mineral oil.
.

I have seen the aftermath of using the wrong oil in brakes more than once.It ain’t pretty.

Me too, Hope diaphragm the size of an elephant’s ear within a day, puddles of fluid under the bike within a week, and a complete scrapped system after leaving it festering in a shed for a couple of months, as the resulting gunge couldn’t be removed.

Having seen the threads on American boards with people recommending baby oil for brake fluid, I’ve often wondered how that turns out too. If seals are specific enough that it matters whether you use Magura or Shimano mineral oil then gawd knows when you get in to using non-recommended fluids.

So long as you understand you’re mucking about with hydraulic ratios and will end up with a brake with characteristics coming from the calliper, hose and lever as a unit that might not be predictable in advance you can mix and match any of the DOT brakes but once you’re into Mineral you really should stay on-brand for the callipers and levers unless you are ok with a brake that might let go without warning.

If seals are specific enough that it matters whether you use Magura or Shimano mineral oil then gawd knows when you get in to using non-recommended fluids.

I don’t think it does matter. I’ve put citroen lmh in shimano brakes with no issues