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How to Replace a Leaky Shower Valve Cartridge

Bob Jackson
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by Bob Jackson

The shower head developed a persistent leak that was growing worse as if the shower handle wouldn’t completely shutoff. The leak wastes water and kept the shower stall wet promoting mold and mildew growth. I traced the problem to a worn out shower valve cartridge that was 12 years old and leaking. Replacing the shower valve cartridge cost less than $40 for parts and fixed the leak.

Shower Leak Repairs

My home was built in 2002. In the 7+ years I’ve owned the home I’ve installed a basement bathroom and repaired shower leaks in two bathrooms – a shower leak behind the wall and a leaky shower drain. The leaky shower valve cartridge was a new problem; at least it didn’t damage the drywall ceiling.

This repair project is a 4-part series:

The end of each article will lead you to next part in the series.

Leaky Shower Head

I have a His & Hers shower in the master bathroom with two independent shower controls and shower heads. Out of habit we always use the one shower on the left side – which as I discovered caused the shower cartridge to wear out and leak. The shower head holds a small amount of water and will drip for a short time after shower is turned off – which is normal. The problem is the shower head was dripping all the time and getting worse by the day. It doesn’t take long for a leak to waste hundreds or thousands of gallons of water resulting in a expensive water bill.

Shower Head Leak Cause by Bad Shower Valve Cartridge
Shower Head Leak Cause by Bad Shower Valve Cartridge

The shower valve escutcheon behind the handle had the DELTA logo which indicates it was manufactured by Delta Faucet Company. Because I didn’t have anything about the shower in my homeowner’s documents I had to look through Delta’s online catalog to identify my shower valve. Matching the pattern on the escutcheon and shower handle trim, I determined my shower is a discontinued Delta Monitor® Classic 1300/1400 series which is similar to the current Monitor® 17 Series Shower.

Master Bathroom Shower
Master Bathroom Shower

Order a Replacement Delta Shower Valve Cartridge

You can find replacement parts, diagrams and instructions at Delta’s Customer Support site then buy it at Amazon at a lower price.

The Delta Customer Support website lists two different shower valve cartridges for the discontinued Delta Classic Monitor 1300/1400 and newer Delta 13 Series showers per the diagram on page 10 of the Delta shower valve installation instructions:

DELTA MultiChoice 13-14 and Monitor 1300-1400 Series Cartridge Reference Sheet RP19804 RP46074 - Copyright Delta Faucet, Inc.
DELTA MultiChoice 13-14 and Monitor 1300-1400 Series Cartridge Reference Sheet RP19804 RP46074 – Copyright Delta Faucet, Inc.

I was confident my shower required the Delta shower cartridge model # RP19804 because the house was built in 2000. I ordered both the RP46074 and RP19804 cartridges because replacing the cartridge requires turning off the house main water supply and I didn’t want be without the right part.

Here’s the new Delta RP19804 with my old leaky shower cartridge and the RP46074. Obviously the RP46074 part doesn’t fit my Monitor 1300/1400 series shower valve because the lower housing water inlets are longer and more narrowly spaced:

DELTA Shower Valve Cartridge Replacement Part # RP19804
DELTA Shower Valve Cartridge Replacement Part # RP19804

Delta Faucet has an excellent shower cartridge replacement video:

How to Replace a Leaky Shower Valve Cartridge

Shutoff the Main Water Supply

The main water supply to the house must be shutoff before replacing the shower valve cartridge.

I installed hot and cold water supply shutoff valves when I built the basement bathroom shower which avoids this hassle. Unfortunately the home builder didn’t install shutoff valves for the master bathroom shower.

I have the option of turning off the water supply at the city water meter by the street or the secondary valve inside the basement. I chose to turn off the water at the basement secondary valve:

House Water Supply Shutoff Valve
House Water Supply Shutoff Valve

The water must be drained from the pipes inside the house. My house has two floors so I went upstairs and opened the bathroom faucets and shower valves to drain the water through the lower level fixtures. I also did the same for the kitchen sink and bathrooms on the main floor followed by the basement bathroom which is at the lowest level in the house. The pipes emptied in a couple of minutes. Leave the faucets open while replacing the shower cartridge to allow any residual water to drain.

Remove the Shower Valve Handle

The shower handle is held onto the shower valve stem by a set screw. I removed it with a 1/8 inch Allen wrench:

Remove the Shower Handle Set Screw
Remove the Shower Handle Set Screw

The set screw and shower handle was a little difficult to remove due to the years of soap scum and calcium build-up:

Remove the Shower Valve Handle
Remove the Shower Valve Handle

Remove the Shower Valve Escutcheon

The escutcheon is fastened with two long screws – just remove the screws to take off trim plate. Notice the word “Monitor” embossed on the escutcheon which helped me identify the shower valve as a Delta Monitor 1300/1400 series:

Shower Valve Escutcheon Removal - Long Screws
Shower Valve Escutcheon Removal – Long Screws

The shower valve escutcheon and two long screws. The bottom of the plate is towards to the top of the photo with the small V notch in the rim for drainage:

Remove the Shower Valve Escutcheon
Remove the Shower Valve Escutcheon

The shower valve cartridge is removed in How to Remove a Leaky Shower Valve Cartridge.

Take care,

Bob Jackson

Delta shower cartridge RP19804Delta shower cartridge RP46074how to fix a shower leakleaky shower valve repair
Bob Jackson
Bob Jackson
Technology product manager by day and a prolific handyman in the evenings and over the weekends. Bob was the founder of the original Handyman How To website and that tradition continues on this site with excellent new handyman content into the future.
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