Not sure what style of adjuster is used on the front, IH used a cam style for the most part. With that style of adjuster you turned in in direction of normal forward rotation until wheel locked and then back of just enough for wheel to rotate again. If I recall on the back you go towards the axle with the adjuster tool to tighten, and if like IH the upper adjuster is a PITA to move. Do you have good engine vacuum to the booster and is the check valve working? Good luck.