have ABS problem brake pedal boggs and go soft
have brake issues abs pedal go soft on 2004 GMC Savana 3500
You really need to scan the ABS computer to see what coded problems are there. You should also do a very careful inspection of your complete brake system. I always do both when I tackle an ABS issue. This problem is a safety issue, so I would make sure that you go to a really good shop.