Abstract: A support system for use in construction or repair of a fire hydrant installation includes a lower bracket and an upper bracket. The upper bracket has an adjustable hydrant riser clamp which is connected to an adjustable hydrant valve casing clamp by an adjustable spacer. The lower bracket also has an adjustable riser clamp connected by a like spacer to an upright bar. Ends of this bar then join a pair of vertically spaced apart adjustable casing clamps. As constructed in an open hole, the hydrant installation includes a hydrant riser that is positively joined to a water main and a valve casing that merely sits with a gravity fit on a hydrant valve located between the main and riser. For use, the lower bracket spacer is placed in an adjustable state allowing its respective clamps to be attached to respective lower ends of the riser and casing. Then, the lower bracket spacer is secured in place. Next, the upper bracket is attached in a like manner to respective upper ends of the riser and casing.