I just finished some brake work and I continue to have a very squishy brake pedal after trying multiple ways to resolve the issue. Here are the facts:

93 240 210kmi
When I purchased it 3+ years ago I installed new calipers, pads, SS brake lines, ATE MC, ATE Dot 4 fluid using Motive pressure bleeder @ 20#. Everything worked ok. Pedal was somewhat squishy and figured it was normal
This past summer, replaced fluid with ATE Dot 4 and Motive pressure bleeder. Seemed to go ok.
Recently the LF brake caliper seized, which I just replaced and bled just that line (see earlier post this week)
At this point the pedal got more squish and goes almost to the floor with the engine running. Never had this in the past.
Decided to bench-bleed the MC just to be safe
Re-bled the entire system in this order per the green book: LR, RR, LF, RF
No change in pedal - still squishy to the floor
With the engine off, the pedal is firm after 2-3 inches of travel

The only thing I've not touched is the ABS modulator. Should I try bleeding that? If so, what is the procedure?

I've heard others say this kind of pedal behavior is normal for a 93 w/ABS. I'm expecting the pedal to be much more firm.

Any other thoughts?

Thanks.