front brake adjustment?

[piecesparts]

There will be a small amount of drag on a disc if the pads are touching. I agree that your problem may just be the front hoses to the discs. If the truck is pulling to the left, then it is probably the right hose is failing and restricting fluid to the disc. Replace both and do a purge of air from the brakes on the front. Your problems may be cured that easily.