How to Clean the Parts and Fix the O-Ring Seals on a Moen Faucet

Even when a Moen faucet has broken, you can clean the parts and reuse them if you replace it with the same faucet, or sell them as used parts.

The faucet I had was leaking, and my usual “quick fix” with Moen is to get a new cartridge installed.  Depending on the model, you can get a cartridge for free.  This one had a limited warranty, so I had to buy one. The fix seemed to work when I tested it, but the leak reappeared.

The cartridge had probably dried out at the hardware store. The way these carts work, all the o-rings need to be pliable and thick.  The handle pulls the piston up, allowing water flow and mixing the hot and cold.  The water exits the cartridge into the chamber that holds the cartridge, and then flows out the faucet.

So, if these seals fail, water flows out into the wrong places, or with too great pressure.  You can revive the pliability and thickness of these o-rings with a plasticizer like AT-205, which is for car parts.

I think that the water chamber in my faucet developed a leak, so, it was broken.

The rest of the parts,  however, were fine. They were just caked with lime and other gunk, all encrusted on the parts.

Clean the Parts with Acid

The main way I clean off lime deposits is acid.  There are two popular acids: hydrochloric acid, and phosphoric acid.  Hydrochloric acid smells a little like lemon. Phosphoric acid smells like cola.

The easiest source of hydrochloric acid is in the garden section of a hardware store, where they sell it as muriatic acid for pools. It’s around $12 for two gallons, and the concentration is 10%.  That’s too strong for regular use, so you should dilute it by pre-mixing it with water in a plastic bucket.  You want the concentration to be around 1%, or even less.

You clean the parts in the weak acid solution. Place them in and wait around 15 minutes for the acid to soften the lime.

Phosphoric acid is safer and easier to use than muriatic acid, but it’s still strong. Two common products that contain phosphoric acid are CLR (aka, Calcium Lime Rust), and blue toilet bowl cleaner that advertises that it’ll clean away lime. It must be the one that deals with rings and lime, not any other ones that may contain bleach.

These both come in a fairly dilute concentration, but you will want to reduce it even more.  They also both contain detergents to break down greases. This may help, because there may be body oils embedded in the lime deposits.

Again, you dilute the acid in water, add the parts, and let it sit around 15 minutes.  The acid will clean the parts. You can usually scrub off some of the lime with a brush.

I used the toilet bowl cleaner, and used very, very little.  Maybe 2 tablespoons per half gallon, and pouring it directly only onto the thickest calcifications.  The stuff was still strong when dilute, and removed not only lime, but a little bit of the chrome plating.

Warnings About Acid Baths

Even a weak acid bath does remove a small amount of metal. Because you clean the parts by allowing the acid to soak in,  you need to make sure you don’t let them sit too long.

This also means that a weak acid bath smooths out the edges of fine scratches, and creates a smoother finish.  It looks nicer, but isn’t a good thing in the long run. The only way to shine up metals and protect them is with some kind of wax or sink gel polish that, instead of removing metal scratches, fills them in with clear material.

Whether using the muriatic or phosphoric acid, I use the leftover waste to scrub out the toilet.  These chemicals aren’t that bad once dilute, but, it’s better to use up the acids by having them react with the lime deposits in your toilet.

Will someone buy the parts?

I hope so. I’m undercutting all the new parts prices.  I might go even lower.

I’m selling these as a kind of “zero waste” offering.  If I had a broken handle, or any of the plastic or metal parts were broken or bent, I’d hate to pay $6 to get a replacement.  This kit is enough to refurb a faucet quickly, and delivery takes one or two days locally.  It includes two cartridges, one nearly new, and one old but “revived” with AT-205.

Other Cleaning Articles

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Decluttering with Ebay, Part 2


One thought on “How to Clean the Parts and Fix the O-Ring Seals on a Moen Faucet”

  1. Short update. Someone bought the parts for $3.50. So $11 shipped. Fees eat up around $1.50 leaving me with $1.50. While it’s basically nothing, it’s better than tossing it into the trash. It could have sold for more if I were willing to store it.

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