Broken plastic T fitting

[SS Cruiser]

Recently I noticed that my water pump was cycling about every 20 seconds. After looking for leaks inside the motorhome, I went out to check the the area around the pump and filter and found a light spray of water coming from a T fitting at the pump outlet.

At first I thought it was a loose hose clamp, but when I started to cut the clamp the T snapped off. I was in Bushnell, Florida at the time and went to an RV parts shop where I was told that the fitting was inadequate for the job and I should replace it with a brass T from a hardware store. The True Value down the street only had white nylon fittings in ½" so that's what I used.

I installed the new T with standard hose clamps and all is well for now. I don't know if this was a manufacturing problem from the FR factory, or perhaps a freeze problem, but I'm thinking that when I get home this spring, I'll replace all of the plastic T and elbow fittings with brass in order to help avoid future incidents.

[phillyg]

The white nylon fitting will probably be more than adequate.

[Flybob]

I see no reason to replace the nylon ones. That failure does not appear to be the result of normal use. Potentially over stressed when clamped or when connected.

[SS Cruiser]

The black plastic fitting looks a lot like an automotive vacuum line fitting. For that type of application, there would probably be a lot less stress than in a plumbing line. Is this type of fitting used regularly in RV plumbing applications?

I will probably go ahead and change them out, if for no other reason than to replace the crimp clamps with standard hose clamps. I've heard of the crimp clamps loosening up over time.

[PenJoe]

Plastic fitting are lighter (aka cheaper) than brass for use in the camper industry. You could probably replace all of the fitting in your unit and not add 2 lbs. I would strongly suggest going with brass fittings on any fittings you replace.

We carry a basic plumbing kit with a variety of 1/2" brass Pex fittings, a Pex crimping tool and a bag of 1/2" Pex cinch clamps. The crimping tool is designed so that it will not release until the clamp is fully cinched, so no leaks. The tool works for other diameters of pipe as-well. It's just cheap insurance as other will attest.

Amazon has a reasonably priced crimper and cinch clamp if you are interested. http://www.amazon.com/Pex-Cinch-Clam...+crimping+tool

[PenJoe]

Unless the cinch clamps were not set properly, which would be very difficult, they won't loosen up. Pex has become a standard in the home building industry. We have had Pex plumbing in our residence for 11 years without a leak.

[SS Cruiser]

PenJoe, thanks for the info. What I was referring to as crimp clamps are obviously pex cinch clamps. I can see their advantage when putting things together, but they sure do make it a lot harder when you have to disassemble things.

[PenJoe]

There are two ways that I know to remove a cinch clamp:
1. Just to the side of the crown, you can see where the ring slides over itself and locks together like a zip tie and ends. Slip a very thin screw driver between them and pry up releasing it from the locking notch. To me, that's the hard way.
2. Use an angle grinder with a very thin diamond blade and very carefully cut the crown off. This is the method I use if I have working space. If you use this method, hold the grinder steady and firmly and use very light pressure to keep the grinder from jumping. Wear safety glasses.

[KenHwy61]

You can also use a side cutter to cut the ear of the clamp off. Then the clamp will pull off easily. I have a pair of cinch clamp pliers made for installing and removing clamps. They are made by Knipex and make quick work of doing PEX.

[Thurman]

That black plastic was made from "polypropylene" plastic. Poly = cheap with no strength. The white material is most likely a "glass filled" plastic. This means that very tiny fiberglass fibers are added to that plastic to strengthen the plastic. The white material is most likely "Polyolefine" which has much better characteristics than the black poly.

[KenHwy61]

Good to know. Also that isn't even the right kind of fitting for that type of tubing. Should be barbed fitting for braided tubing. That is a PEX fitting.