SOLVED: Bleeding front brake from hell.

You have to be careful with vaccum bleeders as they at times will produce bubbles, but that is from a bad seal at the zerk on your bleed hose and not within the actual system. They work great imo, but just be mindful the bubbles can be deceiving. I suspect there is still some air trapped somewhere in the master/caliper. Perhaps try some tapping/suspending the caliper above the master for a few hours. Then keep working it. No other reason you wouldn't be able to build adequate pressure otherwise. 

Like I said, try some tapping on the caliper and master. Screwdriver handle should be plenty. Hopefully that helps to uncork any residual air trapped inside either. 

OEM pistons and seals?

Did you bench bleed the master before attaching the line?

What is wrong with your current OE pistons? .10 mm in overall diameter should make that much a difference 

It’s where you bleed the master into itself before attaching it to the rest of the system, typically with a fitting that attaches where the brake line would, with a short hose that runs back into the reservoir. This allows you to bleed all air out of the master cylinder assembly prior to trying to bleed the rest of the system. On many systems, if this step is skipped it will be difficult or impossible to get the system bled.

Two other tricks are:

-using a pressure bleeder (you can make one using a small garden sprayer and an adapter from a spare master cylinder cap)

-bleeding as best you can, then tightening the bleeder valve and zip-tying the brake lever in the “brake on” position against the bars overnight. Prior to letting it sit, use a screwdriver handle or soft hammer to tap all the way from the caliper, along the line, to the master cylinder to free stuck bubbles. This trick has worked more than once when I did everything else and couldn’t get firm brakes.

Get a syringe and reverse bleed.  Then once you've got a solid bleed on it you can gravity bleed it from then on out.

may i suggest going back to the original banjos? i had a similar issue, i've had my 2003 yz 125 from new and decided to put some braided hoses and new ti bajos and bleed nipples, i spent way to many hours pulling my hair out, decided to go backwards ie put in the original nipples, nothing, then went back to the oem banjos, instant pressure, im now back to a excellent brake how it always was, hope you solve your issue buddy 

I was going to say this. Once you have filled the system, seal up the master cylinder and gently pull on the syringe to "pump" fluid back and forth. You can see any trapped air bubbles that way. 

If you can figure out a way to connect at the master cylinder banjo bolt, do the MTB thing and try to get two syringes; one at the top and one at the bottom. You can then force fluid out of a full syringe at bottom into the mostly empty one at top. This should get you at least 90% there. 

Another dumb idea but it hasn’t directly been addressed in the thread. Tighten your fittings at your master cylinder and your banjo bolt just a little more. My buddy had a decent get off last year and broke the mount to his master cylinder necessitating a new MC. We bled and bled that for way longer than we care to admit but couldn’t get it to hold pressure. We eventually put a wrench on both fittings and went about 1/8 turn tighter than the torque specs for both fittings and the brake system then started to hold pressure. 

glad you solved it buddy, id zip tie brake blade to the bars now for 24 hours as said above, it helps remove any air from the separator/divider at the bottom of the master

Congrats!

I hate bleeding brakes, especially Brembos.

I now use these KTM tools RELIGIOUSLY as my "continuous bleeding approach" (same concept as zip-tie, just easier to use & see wen you lose in dirt) - and they are amazing at keeping your bike put on an incline/idling, too. Bought one or every bike!

https://www.motosport.com/search?textsearch=KTM%20Powerparts%20brake%20strap