I'm working on daughters new (to her, 21 year old) Honda motorbike.
She would normally do it (under my supervision) but Covid etc etc.

I've done the chain and sprockets (un-seizing the rear brake in the
process) and today replaced the fork seals and dust covers and in the
process, found the front brake caliper to be pretty stiff (single
sided floating caliper with dual pistons) so currently have it on the
bench with some Plus Gas round the pistons.

Now in the past I have forced the pistons out with compressed air
(restricting their travel with suitable blocks of wood / rag / clamps
etc) but feel it would be better to do hydraulically because it would
be more predictable and possibly safer.

So I might hook it back up to the bikes front brake system this time
but I was wondering about rigging up a general purpose hydraulic hand
pump for when I need to do such things.

It seems they do them fairly cheap on eBay and I'm assuming I could
use basic hydraulic fluid (less likely to take the paint off?) but I'd
need to make up some fairly high pressure adaptor hoses (25 bar)?

Is this something one can do diy and if so, do you need any special
tools for the joints etc?

I think the pumps come with a 1/2" male (looks tapered) outlet and so
I'd need a mating female to whatever I was working on, in the case of
most motorbikes, a 'banjo' connection of some sort.

Cheers, T i m