I did a full brake job on my truck 3 months ago. The truck had a spongy peddle and the shoes and pads were gone. After new pads, shoes and turned drums and roters the truck stopped better but the peddle was still spongy. I changed the master cylinder and everything was great, good peddle. Over the last two weeks the peddle has gotten spongy again. I tried bleeding a few times with no improvement. Now it has started pulling to the left and the peddle is worse. Got any ideas?