1992 Isuzu Trooper breaks

Not sure if it has abs I was told it has rear abs(not sure how to find out ) I picked up the truck just this summer .

Reason was I needed an inspection. When that was done the repair man said the pedal was too soft and too low he failed me

so we took the wheels off and looked at the system and it all looked original
we bleed the system and notice that two front calipers weren't releasing so decided to change all four as well as the master and all 4 pads
bleed the system again and all seamed well so drove for a while (15-20 min ). Soon enough the front pads were smoking started to lock up (not sure if all 4 were locking ). We were stumped

a fellow repair man told me about the portioning valve under the master (that was changed) drove home and locked up again now all 4 were locked. To move the vehicle I released presser on one of lines on the portioning valve all 4 released -drove home

then we also adjusted a pin under the dash on the break pedal. This worked for a day. And first thing in the morning they locked again
I know when I push the truck (drive I little aggressive) it starts to build pressure
and seems going up hill tends to drag (not sure if that is just me being stressed out. Lol

thank you for your time