Murdock Hydrants: Installation Instructions for M-75 & M-E75

Installation Instructions

Trench Preparation: Prepare a trench for the Water-Supply line. Below the hydrant location, excavate a hole large enough for a person to work, extending to the trench depth. Lay the Water-Supply Line and Waste Line (if required) into the trench, ensuring extra line length for trimming during hook-up. A drain line may also be required depending on design and code requirements.

Hydrant Installation: Install the hydrant fully assembled. Position it at the desired location. Brace the hydrant by placing two boards across the hole and under the Hydrant Base, one on each side of the outer casing. Use a bubble level against the Hydrant to ensure it is plumb, adjusting the bracing boards as needed.

Water-Supply Line Purge: Connect the Water-Supply Line, trimming the length as necessary. The water pressure should not exceed 85 psi. If required, install a Pressure-Reducing Valve in the Supply Line. Wrap the bottom Drain opening with Filter Fabric. IMPORTANT: Place a minimum of three cubic feet (0.085 cubic meter) of large, round rock under the drain opening. Local codes and soil conditions may necessitate more rock for adequate drainage.

Back-filling: Back-fill the trench and hole, compacting the earth. Remove the bracing boards. If necessary, loosen the set screw in the base and adjust the vertical position of the base on the outer casing so that the bottom of the flared part of the base is at grade level.

Concrete Slab: If a concrete slab is desired, prepare the hole surrounding the hydrant to accommodate it. Spread and compact gravel as necessary. Pour concrete up to the bottom of the flared part of the Hydrant Base. Finish the concrete as required.

Diagram showing hydrant installation components: Hydrant, Level, Base with set screw, Concrete, Gravel, Earth, 2" black pipe, Frost line, M-E75 Unit with 3/4" Supply Connection (Female) from below hydrant, Minimum 3 cubic feet of large, round rock, Tail assembly with 3/4" I.P.S. (Male) supply connection, Supply line with fitting (by others).

Maintenance Instructions

All normal maintenance is performed from above grade. Washers should typically be replaced annually. Refer to "Replacing Washers".

Disassembly: Remove the Top Bolts and Nuts securing the Top to the Stock. Lift the Top from the Stock, sliding the Screw Flange under the Top from the Stirrup. Unscrew and remove the Nozzle from the Stock, carefully catching the Slide. Grasp the Stirrup and raise the Supply-Line Assembly out of the Stock-and-Outer-Casing Assembly.

Washer Replacement: At the bottom of the Supply-Line Assembly, unscrew the Packing Ring from the Valve Body. Remove the Ring Washer and Cup Washer. Remove the Seat-Washer Screw and Seat Washer. Replace the Seat Washer. Replace the Cup Washer and Ring Washer. Tighten the valve packing ring hand-tight to keep the cup and ring washers in place. Screw the Packing Ring back into the Valve Body.

Reassembly: Gently lower the Supply-Line Assembly into the Stock. As the Stirrup nears the top of the Stock, carefully lower the assembly to ensure the Valve Body seats properly over the valve Stem underground. Rotate the Stirrup to align the Nozzle opening in the Tee with the opening in the Stock. Ensure the tee end of the Nozzle is inserted through the slide with the tongue of the Slide oriented toward the Tee end of the Nozzle. Apply pipe-joint compound to the Tee end of the Nozzle. Insert the Tee end of the Nozzle through the opening in the Stock and screw the Nozzle into the Tee.

Ensure the long side of the Slide is oriented upward and the Slide Tongue fits into the groove in the Stock. Tighten the Nozzle, ensuring the Nozzle Outlet is oriented downward.

Diagram showing hydrant internal components: Top & handle, Bolt, Stirrup, Nut, Slide, Nozzle, Valve body, Seat washer, Screw, Cup washer, Ring washer, Packing ring.

Replacement of Washers

1. Turn off the water supply to the Hydrant.
2. Remove the Nozzle and Top Bolts. The Nozzle is removed by turning the locknut counterclockwise.
3. Pull the complete inner works assembly out of the hydrant casing.
4. The Washers are located in the brass valve body at the lower end of the inner works.
5. Remove the valve packing ring, cup and ring washers using a flat screwdriver, and the screw holding the seat washer in place.
6. Replace the seat, cup, and ring washers. Tighten the valve packing ring hand-tight to keep the cup and ring washers in place.
7. Re-assemble the hydrant in the reverse order of disassembly.

For further assistance, please refer to the provided link or QR code for a troubleshooting video.

Replacement Parts, Kits, & Tooling

NOTE: Apply Vaseline when replacing Gasket.

Items 1-11 are intended for both M-75 & M-E75 models.

M-75 Unit: Items 12-16 are intended for this unit.

M-E75 Unit: Item 17 is intended for this unit.

Diagram illustrating replacement parts with numbered callouts.