In the middle of doing a brake job on my 04 track Z with Stoptech BBK.
Anyone ever come across a bad brake master cylinder? And what symptoms would let me know that its bad?
The brakes would bleed diagonally, from front left to rear right, but wouldn't bleed front right to left rear.
Could I have a bad brake cylinder?

 

You probably have air in the ABS unit causing it not to bleed. If is a two chamber master, one front, one rear , if you get one front and one rear to bleed, it is working and you have other problems

 

Only way to bleed is by vac bleeder?

 

Well ordered a brake master cylinder should be here this afternoon.
Tried bleeding it again with no luck. No air has gotten in the system as we kept the master reservoir full of fluid

 

Clamp all 4 brake lines. Press brake pedal down. If all the way to the floor.... master cylinder

 

I do a conventional bleed with a motive hooked up for more power.

 

Well, we replaced the brake master, and sure enough it wasn't allowing one line to bleed.
Got the new brake master cylinder installed after bench bledding, ATE Super Blue fluid in, and did a good bleed. Bedded the brakes and going to do another bleed tomorrow, as the pedal feels a bit squishy.
One of the lines from the BMC, wasn't fully allowing full flow and pressure, and was showing air bubbles in the line. The 350Z has a diagonal split brake system, each line controls one front caliper, and one rear.

Happy to have solved the issue!!