I have always simply done the RR, LR, RF, and LF brake bleed, only opening the bleeder with pressure on the pedal and have never had a problem but according to Auto Zone'* tech pages for the Bonneville, that is not the correct procedure for all Bonnes with ABS.

One brake system, the Delco Vi and Bosch V, calls for a pressure bleed while the ABS valves are being actuated via a scan tool.

From the Auto Zone Home Page, select 95 Bonneville, then vehicle repair guides, then brakes...lots of stuff on several different brake systems for the cars covered.

TIA

Not a brake expert. I like you have always done bleeding "old school" and didnt realize so much trouble and the use of a scanner was needed to do it properly.

Still I cant think of any reason the master cylinder should fail like this, regardless of the bleeding procedure used. I am apt to think the store you bought these from is sourcing substandard parts.

Sundays are slow here, but a couple moderators here know brakes well. I'm sure they will pipe in.

I was messing around and noticed some oil-like drops on the floor - I think it may just be a rusted brake line..now to find my flare kit...and bleed again.

Also a public apology for the copy writed info I posted in the other thread.

If I do find a rusted line that should be the smoking gun.

Dont give it a second thought, I have done the same in the past. As mentioned, commercial businesses are getting anal about it. So posting a link, then copy/pasting an entire procedure as well just isn't prudent.