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

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…

“I was at my witts end with a 39 year old American Standard faucet. It had been leaking for many, many months so I contacted American Standard. They referred me to Noel’s Plumbing. My faucet would not have been able to be replaced without removing the whole tub. They immediately contacted me and told me what to do. They stayed with me the whole time till I found the problem although they didn’t get a sale out of me they did fix my problem no more leaky faucet, I have them in my contacts now and will use them anytime I have a plumbing problem. Thank you Noels Plumbing for the best service I’ve ever had!! ”

-as

02/22/2024

$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.

We can ship anywhere the US Postal Service ships. For orders being shipped outside the US, please contact us at (888) ASK-NOEL, noelsplumbingsupply@fuse.net, or via the text widget on this screen.

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Mansfield Stem Assembly for 10″ Series 300 Hydrant

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.

Common questions about this product

Yes, this is the OEM recommended part.

If you’re not sure text us a picture 1-888-275-6635 or email us a picture at noelsplumbingsupply@fuse.net.

We will make sure you have the right part.

WHAT OUR CUSTOMERS SAY…

“The cartridge in my kitchen sink broke last week so I've been without that sink for a whole week. I ordered a replacement from Noel's, which I could not find anywhere else and it worked perfectly. Thank you! You saved me! ”

-Matt F.

09/19/2025