Shower Mix Valve Repair/Replace??

[Condoluminum]

It's now time to fix annoying drip drip from shower head. Mixing valve doesn't appear to be Moen, and may have been replacement by PO. Plastic knob rotates 270 degrees from off to full hot, and pops off with spring-loaded button at bottom. Trailer is 1988 Excella 25, with center bath on street side. Local hardware center thought it might be old American Std unit, and body and internals are plastic inside brass cast housing. Removed mixer stem.pads and tried to match, but nothing similar in plumbing repair section of Home Depot or similar local large hardware center with an entire aisle of plumbing valve replacement parts... No amount of adjusting valve stem or tightening plastic retaining ring nut or larger brass ring nut will stop leak drips with city or pump pressure... Valve has 4 1/2" inlets - left and right cold and hot, and upper and lower outlets for tub and shower, with one plugged... Good news is that piping inside bath cabinet hasn't leaked..

Gray pex piping has several couplings with metal bands on each inlet, further implying it was replaced, rather than factory unit..

Options include trying to remove entire nylon body from brass casting and taking to serious plumbing supply shop, or cutting grey tubing, replacing with new Moen or equivalent, and using more couplings to rejoin piping where cut... Or maybe undoing metal bands on existing couplings, though I gather that requires expensive and exotic tool.. We do have several very large rental shops around which might have special tools...

Any recommendations? I'm comfy with plumbing, teflon tape and thread compound, PVC sprinkler piping and home bath drain repairs...

John McG

[j54mark]

The grey tubing is polybutylene and is factory. The connectors were crimped on using little aluminum (?) bands.

Just pick out a shower contol you like and replace the existing one. Flair-it fittings will fit your grey tubing, I believe. I know the grey plastic Qest fittings will work but I have found them less that 100% reliable.

Good luck,

Mark

[Bob Thompson]

Some of the parts look exactly like the Moen control in my '97 Excella, so I'm betting it is a Moen. About 2 months back my Moen started to leak, so I replaced the nylon cartridge and problem solved. Most home centers carry replacement cartridges for Moen's for about $20. Remove the center cap of the knob, loosen the screw inside, and remove the knob, there is probably a stainless steel cover over the main brass housing so remove it. You should be able to see a "y" shaped clip that holds the nylon cartridge in. Pull the "Y" shaped clip out the side of the brass body. You should now be able to use a pair of pliers to pull the cartridge out. Pay close attention to the orientation of the holes in the cartridge when you pull it out. Put the new one back with the same orientation. Enjoy!

[Condoluminum]

Thanks for note on Flair-it fittings.. I'd seen the other thread on plumbing and recommendations from other postings.. Are they available at Lowe's & Home Depot kinds of places, or are they strictly at RV places? Sounds like no special tools or crimpers or other exotic tooling required...

And as for brand, I had center shaft/mix valve stem in hand and both plumbing dept guys at big box stores said not a Moen, and unlike any Moen cartridges or replacement stems.. I did see parts ID manual at Airstream dealer, and my valve looked very different from drawing and cutaways in the Airstream manual...

John McG

[j54mark]

I got Flair-it brand connectors at a local Ace Hardware store. Others on these forums have reported using on line sources.

And no, it doesn't look like Moen to me either.

Mark

[Ga Pockets]

Hello, My 88 had a similar problem ( it has the same mixing valve as your photo and is original) The hot and cold water is controled or metered by 2 spring loaded valves . These 2 valves are adjustable by using a 5/32 (i think) allen wrench. My owners manual detailed very clearly how to adjust these valves and it worked. I could fax you the instructions if you want but in short , if you pull the control knob of you will see 2 small holes that access the adjustment for the spriings in the valve body , use the allen wrench to either get more or less flow. I took the valve apart just because I wanted to see how it worked and because the access holes would not line up with the screws. When I reassembled it ,I used the allen wrench to maintain alignment. PM me if you want any additional info.

Bill

[Condoluminum]

Thanks Bill..

I too have taken mine apart, but couldn't determine how to adjust for secure cutoff... Are you referring to allen screws on front that appear to adjust the stop points for rotation of the valve? It looks like the shutoff stop is all the way at end of plastic channel already..

I'll try again looking for internal adjustment, but will also run out and get some Flair-its to help install the new Moen valve waiting in the garage just in case...

John McG

[Ga Pockets]

No , those are the comfort settings. There are two small holes on the front of the housing. I had to take a flashlight to finally see them as they are just large enough to get a allen wrench into the adjustment screws. The two spring loaded valves are similar to valves on a engine head with springs to hold them closed on the valve seat. My hot water valve was not opening up enough to get a full flow of hot and my cold let a small stream of water continously. I adjusted the both accordenlly and it works perfectly now. They are located similar to the eyes on the smilie face below when you look at the front of the mixing valve

[Condoluminum]

Just to close this thread out, I was able to find a source for replacement plastic cartridge for the Nibco shower valves used by Airstream in the late 1980's.. Nibco sold these valve lines to others, and design stopped being made. Several Airstream repair folks urged replacement with Moen or Delta...

After much digging, I discovered that Brasscraft Inc in Michigan supplies a standard replacement cartridge, under their part number SL1425, at price under $20... You can order it from plumbing supply places or Lowe's, though almost nobody stocks it, so it is a special order from the factory.

Replacement fairly easy with few step process:

1. Remove plastic rotating knob
2. Remove two long Philips Head screws holding faceplate to valve body
3. Remove large brass ring nut from front of valve
4. Pull out old cartridge with pliers
5. Insert new cartridge into valve body
6. Replace ring nut and tighten
7. Holding face plate in position, re-attach to valve body with long machine screws
8. Using process in manual and long 5/64" Allen wrench adjust the flows of hot and cold water...
9. Re-attach plastic knob

John McG