92 Astro van brake problem

I have a 92 astro van 135093 miles on it with all wheel abs I just replaced all of the lines from the abs block and have bled them yet I still have no brake on the driverside front currently the abs is unhooked because I wasnt able to stop hardly at all with it unhooked im able to stop but still do not have alot of brake pressure and the rear brake constantly lock up as the van slows down the passenger front is working but doenst have enough power to stop the van like it should I have bled all of the brakes and had the abs system checked but still cant figure out what is the problem I have thought of replacing the driver front caliper to see if that fixes the problem but I dont want to spend the extra money I really dont have if I dont have to.