@albertaduke
OK
I needed a coffee and to collect thoughts.
This is all trial and error experience - And I have bled "unbleedable" bikes thus. It also works on Combined Braking Systems (like old Guzzis)- I've never had a bike with ABS so cannot say.
Some of the old tricks spouted on the "never wrong" internet are correct for rubber hoses - but R3's come with PTFE lined hoses and so they do not always work.
I have fitted PTFE hoses since the early 80's on ALL my bikes pretty much from day one.
In damp climates I also PREFER silicone based DOT5 fluids. There will be nay-sayers, I have 35 years-plus of ignoring them.
I have many reasons, but mainly (now) because I have proven most of them WRONG.
The key to "home bleeding" is to make sure that any bubbles (and there are ALWAYS bubbles) will rise all the way to the fluid reservoir uninhibited.
Bubbles are crafty buggers and will stick to any anomaly in the circuit that affords them traction. This can be dirt or a mark in the tube liner surface.
But PTFE hoses generally have a nice smooth inner face. I have seen an issue where the hose inners were marked in the extrusion process - but it is RARE.
99% of bikes have handlebar grips that are lower at the end than where the hose junction is.
In general therefore - I have found that by having the bike on it's side stand and on full left lock the fluid reservoir is at the top of the circuit and that bubbles rising from the left disc do not try and go into the right disk circuit. Rears are occasionally more tricky but the upwards route is key.
Step 1 is to bleed as you would normally. Work from the bottom upwards. I ALWAYS use the bleed screws AND do a banjo bolt bleed - very lightly loosen the banjo and force liquid out (air and shyte can and will collect in the banjo grooves) - the advantage here of DOT5 is is it is not damaging to finishes (like paint). But timely application of a paper towel is equally as good.
Double Banjos are a serious bubble magnet.
If Step one works - all is good with the world. But step 2 & maybe 3 will get your levers rock hard (if you so wish).
Step 2 requires patience. And if you have anything like Barkbusters fitted - remove them. Remove reservoir top. With the palm of your hand on the ball end of the lever (or toe of foot lever) very slowly push the lever until you see a small pulse of disturbance in the fluid. This marks the point at which the system pressurises. On some bikes you can actually just feel this - but on most you need to see it.
Pump the lever VERY fast 4 or 5 times using your palm and release (slowly) - you almost certainly will get a back rush of fluid - have a rag ready. Wait a bit - now very slowly push the lever back to that system pressure point - this will almost always result in a whoosh of bubbles.
Just repeat until (usually quite suddenly) the lever is firm and no more bubbles exit.
Step 3 is both an option and sometimes necessary on very recalcitrant systems - though usually ime due to shyte trapping some bubbles. You pump and then keep the lever depressed a goodly while - often you'll see "tied back" quoted. My personal opinion is that if you need Step3 then you may well should be considering clean (new) components. After a while under pressure the bubbles usually dislodge and then exit with the slow pressure point purge.
If Step 3 does not work 1st time - consider replacing parts - and tbh if you have to go down the rebuild route - rebuild everything.
As some here know - I gift some of my free time each week at a mate's bike workshop. Despite them having vacuum bleeders and even a bottom up pressure bleeder, there are times when the above is still required.
Now I know others will have their own methods. But this has NEVER failed me.