ok, im asking this for my buddy. he has been a toyota mechanic for 20 years, and cant figure his brake problem out. his truck is an 1986. it wont stop worth a crap, but he replaced the front brake calipers, pads, rear shoes, brake cylinders, replaced the rotors, replaced brake booster, and master cylinder and bled and bled the brake system. he has done everything you can possibly do to the brake system and it stops a little better but not like it should. the only thing left he hasnt checked is the load proportioning valve. what do you guys think?

 

Did he bench bleed the MC?
Did he bleed the LSPV?
What is the one thing he hasn't checked?

 

he bench bled the mc but not the lspv. the lspv is the only thing he hasnt replaced or checked