How to Adjust or Repair a Frost Free Yard Hydrant

A typical frost free yard hydrant.

A dripping frost free or freeze proof yard hydrant is more than an unsightly water waster. It is a potentially major problem. This is because a dripping frost free hydrant is no longer frost free. The above ground portion is filled with water and will freeze and potentially burst in cold weather.

Difficulty:

Moderate

Instructions

Things You'll Need

• Pipe wrenches
• Standard wrenched
• Pipe dope
• Replacement valve assembly (if needed)

1. Adjust the nuts located on the connecting rod to increase seating pressure.

   Adjustment
   Worn linkages can cause a leak by not properly forcing the rubber shut off assembly into the valve seat. If the handle is nearly all the way down before you feel resistance caused by the plunger hitting the valve seat this may be the problem. Simply adjusting the mechanism at the top of the valve stem to extend it slightly might solve the problem. The Merril hydrant shown has a double nut arrangement that allows adjustment. Make the adjustments in small increments to avoid damaging the valve assembly.

   If this doesn't fix the problem read on!

2. Components of the valve assembly showing old worn gaskets.

   Repair
   Often the cause of a leaking hydrant is worn or damaged gaskets in the valve assembly. Don't panic. These components can often be replaced without digging up the valve assembly.

3. Find a supplier for your brand of hydrant. Unless you can leave the hydrant unassembled for several days you will want to purchase replacement parts BEFORE starting work. Well drillers are often the folks who installed the hydrant in the first place. They are a likely supplier of replacement parts.

4. Pipes extend the handles of the pipe wrenches fo a bit of extra leverage!

   Unscrew the head assembly from the riser pipe. This might be difficult since it has likely been many years outside and may be rusted tight. Liberal use of penetrating oil, hammer tapping, and long handles on the pipe wrenches can all help.

5. A word of caution. When I unthreaded the head assembly, the screw that held on the plunger assembly unthreaded. When I pulled up the connector rod the plunger assembly remained at the bottom of the riser pipe. This necessitated digging up the entire assembly. I'm not sure how this can be prevented.

6. Connector rod end with the seals and spring mechanism for a Merril frost free hydrant.

   Pull up the connector rod. The seals and valve mechanism should come with it.

7. Replace those components that seem worn or deteriorated. The Merril hydrant allows the entire valve assembly to be separated from the connecting rod via a threaded coupling. Replacing the entire assembly might be the easiest solution in that case.

8. Reinsert the valve assembly and thread the head assembly onto the riser pipe. Be sure to use pipe dope to both aid in sealing and easing disassembly at some future date.

   Adjust the plunger seating pressure as noted above.

9. Be sure the riser pipe is draining when the valve is closed. (Place the spigot in a glass of water. The spigot should siphon the water out of a glass as the water drains down the riser pipe.)

10. A plugged drainage port can sometimes be forced open by attaching a garden hose with a closed nozzle, pressurize the hose, then shut off the valve. The hose acts as a pressure reservoir and may blow out the blockage. Repeat several times before giving up.

Tips & Warnings

• Replacement of the entire hydrant may be you only option if none of this solves the problem.

• A leaking frost free yard hydrant needs to be repaired before cold weather can freeze the system possibly bursting a pipe and causing a lot of damage.