Mansfield by Prier M-123-5034 300 Series 10" Stem Assembly

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Copper stem with bright brass coarse threaded end with black rubber washer brass screw metal washer and grey graphite packings.

Complete 300 series faucet picture with grey handle polished chrome body copper tube and brass end.

WHAT OUR CUSTOMERS SAY…

“Love Noel's Plumbing Supply! They are one of my favorite oddball plumbing parts purveyors. As a professional plumber, I rely on sites like Noel's to keep antique and rare fixtures alive. My customers and I are so grateful! ”

-Danielle E.

03/25/2026

$46.47

This item is a complete replacement stem assembly for the “original style” 300 series Mansfield wall hydrants (manufactured between 1970 and 2013), made by Prier Products.

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Whether you’re fixing a persistent leak or performing routine seasonal maintenance, this genuine replacement ensures a perfect fit for 10-inch wall depth hydrants. The assembly comes pre-equipped with necessary washers and both left- and right-hand graphite packings, making it a versatile “DIY-friendly” solution for older plumbing systems.

M-123-5034

The stem assembly has an overall length of 13 7/8 inches.
It is specifically designed for an 10-inch wall depth, measured from the back of the face plate to the water shut-off. It replaces the stem in a 378-08 or 379-08 hydrant.
The packaging includes the stem assembly, a metal O-ring, a support washer, and both left-hand (large flat) and right-hand (small thick) graphite packings to accommodate different faucet types.

Related Documents

300 Series Faucet Parts Breakdown

UPC:670210370158

Customer submitted images.