Mysterious leak

[Freep]

At the end of the season prior to putting the camper away for winter I suddenly got a leak coming out of the rear of the TC. It was too cold to do anything about it so I drained everything and waited until spring. So today I started going through everything trying to determine where it was coming from.

Having reworked a lot of the plumbing, the first thing I did was put some water in the fresh tank and pressurize the system. Well, that failed. I needed to prime the pump. After futzing around with that for a while I was finally able to get water in the system using the winterizing bypass but I couldn't get any water from the fresh tank.

But with a pail of water and using the bypass I was able to rule out the pressurized fresh water lines. No leaks under pressure.

So I started freaking out thinking that there was a leak from the fresh tank to the pump. No water was leaking yet but it could have been a slow leak and hadn't made it to the plumbing drain access at the rear of the camper yet. So I opened up a couple of the access panels to take a look and they were all dry.

By this time there was water in the plumbing drain access area and lucky for me, it was still pretty dusty from the final trip. This made it easy to identify the source of the leak. It's an elbow joint in the grey line coming from the grey tank to the discharge valve, right where the pipe joins the elbow. cr@p cr@p cr@p.

At least I know where it is, but what a pain to fix. Why couldn't I have a leak under the sink? Everything is tight in a TC but this just turned into a major repair.

So I started looking around to see if there was a way to repair a leak in a PVC joint without removing it. I found a couple of products and I almost pulled the trigger on them but then I found this and this


So in a couple of days, when I finish my other tasks, I'm going to fix that PVC joint with primer, glue, a vacuum and some tape.

Edit: This worked. I found a hairline fracture about 3 inches long. I could just fit my arm into the space to apply the primer and the cement and had a helper work the vacuum. I filled the grey tank this morning and still no leak.

[Grit_dog]

Wow, nice job!
Learn something new everyday!
I’ve never seen vacuuming glue into a pvc pipe crack....not to be confused with a crack pipe!

[Freep]

Grit dog wrote:
Been around a lot of frozen pipes of differing materials.
Freeze damage to pvc most likely would result in cracking the pipe or possibly breaking the bond at a weak connection.
It wouldn’t widen any pinholes so to speak. If it froze and broke it would be broke.

You are correct. I found the crack and fixed it using the method described. I could just get my arm in there to apply the primer and cement. This method saved me a lot of time and money.

[mountainkowboy]

I discovered that my 1 way valve on the city water supply leaks when the pump is on and doesn't with city water hooked up. I will change it when it comes out of hibernation.

[Grit_dog]

Been around a lot of frozen pipes of differing materials.
Freeze damage to pvc most likely would result in cracking the pipe or possibly breaking the bond at a weak connection.
It wouldn’t widen any pinholes so to speak. If it froze and broke it would be broke.

[Freep]

joerg68 wrote:
On the plus side, there is hardly any pressure on these lines.
But what caused the leak? Aging, vibrations? Or did the grey water tank shift and cause new stresses on the lines?

When we first got this camper we had a problem with the connection from the grey tank to the shower. The manufacturer didn't connect it properly. I'm guessing it was a combination of original shabby work and age and jostling. We went on a lot of bumpy roads last year. Also, before I winterized it we had an early freeze after I filled the FW lines with antifreeze, before I emptied the grey and black tanks. I figured I'd be OK with the amount of soap and antifreeze that was already in the tanks so I didn't worry too much about it.

If there was already a pinhole in the fitting a little bit of frozen water could have widened it.

[joerg68]

On the plus side, there is hardly any pressure on these lines.
But what caused the leak? Aging, vibrations? Or did the grey water tank shift and cause new stresses on the lines?

[Grit_dog]

So it’s low pressure, that’s good. And not the black tank, even better!
Silicone repair wrap may work if you can get all the way around the pipe.
Or can you cut out the bad connection with a wire saw and then replace ?
Use a fernco coupler on one end or compression coupler?

[ScottG]

Grey is Cpvc and you can either use the same material fittings or it can be joined to PVC fittings using "Weld*on" orange label 724 adhesive.

[Freep]

Kayteg1 wrote:
Is it black ABS pipe?
Those use thinner-based glues, meaning the glue is actually melting original material (just like steel welding).
Meaning you can file V-grove in the crack and with few application with dry time between- rebuild the fitting.

It's grey in color. Maybe it's ABS. I'm not sure.

There is no crack, it's leaking from the fitting which leads me to believe there wasn't a great seal to begin with and there was one bump too many.

[Kayteg1]

Is it black ABS pipe?
Those use thinner-based glues, meaning the glue is actually melting original material (just like steel welding).
Meaning you can file V-grove in the crack and with few application with dry time between- rebuild the fitting.

[ScottG]

I've fixed leaks in plumbing by just using the appropriate PVC or ABS cements. If it's a crack, fill it with the glue and then apply a couple more layers. For a stronger fix, cut a suitable coupling long-ways and apply it as a patch.