Sounds like you've tried everything many times. This may be an issue with the new lines or a small leak in the connections causing the bubbles to come back. I would just put on the old lines and see it they stiffen. It's worth a try since nothing else is working. From my experience I never needed any special tools, just stick to the old fashioned 2 person bleed technique, but reverse troubleshoot by using the old lines...
Might as well switch back to the inexpensive brake fluid till it's figured out. Have you tried letting the engine idle while bleeding?
Might as well switch back to the inexpensive brake fluid till it's figured out. Have you tried letting the engine idle while bleeding?
