Repairing Leak in Plumbing - What Am I Doing Wrong?

[aarogb]

Hi,

I had my pump strainer basket broke so I replaced it and did the plumbing job myself to repair the plumbing and add in unions so it would be easier to repair in the future. I did a pretty shoddy job, but it lasted through this past summer thanks to Flex Seal (lol, I know)

The Flex Seal is starting to fail this summer and it’s leaking pretty bad now and air is getting to my lines and the flow light is red on my SWG so it’s not producing chlorine…

It’s really leaking in two areas, where the plumbing adapter threads into my Pentair 340400 pump and at the vertical union in the O-ring. See the pics below:







The big leak is at the threaded adapter. I used Teflon tape both times trying to repair this and it's still leaking. Is there any other product that I could use to seal it? When I first unscrewed it from when it was installed, there was some "playdoh" like material, but I am not sure what that is to buy it again...

Not sure why the union is leaking either, the two sides of the union are pretty tight together and I screwed it down tight.

Thanks for the help!

Aaron

 

[Stump]

I have the best opportunity to be leak free by not treating threaded PVC like metal pipe. I hand tighten then finished with 1 to 2 turns. It is easy to strain the male threads. Using sealant tape only adds to the problem. I used this sealant with success, But I feel it was just not over tightening

 

[setsailsoon]

Aaron,

This fitting can be problematic. I've been able to make it work multiple times with tfe paste as well. Key is make sure threads really are clean. Here is a video of another "trick" using silicone sealer. I don't like using silicone for this as it seems to make everything worse and takes at least 8 hours to set. The unions are usually easy to seal but it needs the o-ring that should be in one of the mating surfaces. Sounds like the o-ring is missing. Make sure the surfaces are very clean and the o-ring is sealing. Nothing is needed for a union other than water soluble silicone so the ring stays in position as the union is tightened. Hand snug plus 1 turn max and make sure the surfaces are mating up square. Sometimes it helps to shake the union a little as it's tightened.

Chris

 

[aarogb]

Thanks @setsailsoon & @Stump. Silly question for you, if I use that TFE paste, will I be able to unscrew the adapter if needed in the future? Or does it work like PVC cement where it's pretty much permanent?

Also, @setsailsoon I noticed when I was priming and gluing the pipe to one end of the union, some glue/primer dripping down and got on the O-ring and base of the union that touches the other part of the union. Would that be enough to prevent it from forming a watertight seal? I didn't think it would be, so I went ahead and finished the job. I have a feeling I am going to regret doing that though...

Thanks

Aaron

 

[Stump]

You will be able to take apart if needed.

 

[duraleigh]

I think your problem may have been the teflon tape. It doesn't seem to work well for me above 3/4 - 1" so "pipe dope" is the answer. I have used Rectorseal by brand but there a many good ones. You don't need much but cover both male and female threads to get a good wterproof joint.

The unions have to mate up just right and MUST HAVE the rubber o-ring in place. Try it again......you'll get it solved!

 

[setsailsoon]

Thanks @setsailsoon & @Stump. Silly question for you, if I use that TFE paste, will I be able to unscrew the adapter if needed in the future? Or does it work like PVC cement where it's pretty much permanent?

Also, @setsailsoon I noticed when I was priming and gluing the pipe to one end of the union, some glue/primer dripping down and got on the O-ring and base of the union that touches the other part of the union. Would that be enough to prevent it from forming a watertight seal? I didn't think it would be, so I went ahead and finished the job. I have a feeling I am going to regret doing that though...

Thanks

Aaron

Most pipe plumber's putty and TFE pastes do thicken a little with age but they do come apart with a little force. It's not at all like pvc cement. Also, that's one reason I never use silicone sealant for this. It sets up flexible but it is definitely set up and a mess to clean up if you need to reuse.

Glue and primer will really mess up the o-ring and the mating surfaces. You probably need to replace them. There are many videos on how to do this right and it sounds like you used too much primer/glue plus had them in the wrong orientation when you applied primer/glue. You'll see this is pretty easy to do when you get the knack of it. Whenever I have a lot of pvc work to do I practice up on a few easy parts. You get better at it pretty quickly. Wow you've got Dave commenting! @duraleigh is one of the original originals here from waay back.

Chris

 

[aarogb]

I think your problem may have been the teflon tape. It doesn't seem to work well for me above 3/4 - 1" so "pipe dope" is the answer. I have used Rectorseal by brand but there a many good ones. You don't need much but cover both male and female threads to get a good wterproof joint.

The unions have to mate up just right and MUST HAVE the rubber o-ring in place. Try it again......you'll get it solved!

Thank you very much, @duraleigh. I will swing by Lowe's and pick that up today. One question though, would this work as the "pipe dope"? https://www.lowes.com/pd/Oatey-Great-White-Sealant/4750813

I see others posting about TFE and this is PTFE. Not sure that there is a difference, but I have never used this stuff before and wanted to check with the pros.

Thanks

Aaron

 

[aarogb]

Most pipe plumber's putty and TFE pastes do thicken a little with age but they do come apart with a little force. It's not at all like pvc cement. Also, that's one reason I never use silicone sealant for this. It sets up flexible but it is definitely set up and a mess to clean up if you need to reuse.

Glue and primer will really mess up the o-ring and the mating surfaces. You probably need to replace them. There are many videos on how to do this right and it sounds like you used too much primer/glue plus had them in the wrong orientation when you applied primer/glue. You'll see this is pretty easy to do when you get the knack of it. Whenever I have a lot of pvc work to do I practice up on a few easy parts. You get better at it pretty quickly. Wow you've got Dave commenting! @duraleigh is one of the original originals here from waay back.

Chris

Thanks, @setsailsoon I will practice a little today with the unions and try again once I have the "pipe dope."

 

[sktn77a]

I wouldn't use anything with (P)TFE in it for threaded PVC pipe. Rectorseal T2 is designed for PVC pipe (unlike some other metal pipe dopes) and should be sufficient for your threaded joint. Use plenty of silicon/teflon sealer all over your union and O-ring - try not to leave any contact area un-lubed. You sometimes have to screw these union parts in pretty tight, especially if the aren't perfectly aligned.

 

[aarogb]

I wouldn't use anything with (P)TFE in it for threaded PVC pipe. Rectorseal T2 is designed for PVC pipe (unlike some other metal pipe dopes) and should be sufficient for your threaded joint. Use plenty of silicon/teflon sealer all over your union and O-ring - try not to leave any contact area un-lubed. You sometimes have to screw these union parts in pretty tight, especially if the aren't perfectly aligned.

Thanks @sktn77a. That's the type of Rectorseal that I bought.

 

[aarogb]

OK guys, still having issues. There is no longer a leak at the union after I put a new one on. However, this threaded connection is going to be the death of me. Now it's leaking more than when I used just Teflon tape. Here are some pics of what it looks like:









Not sure what else I can try? I have checked the threads both in the pump and in the adapter and they all seem good. Nothing broken.

Thanks

Aaron

 

[sktn77a]

That's the right stuff. That pump appears to have both internal threads (that you are using) and external threads (for a 2"pipe?)

You might want to use the connector's external threads as you can tighten them more without as much fear of cracking the pump connector.

 

[aarogb]

OK I think I figured it out. For whatever reason, I couldn't get the PTFE paste to work for me. I went back to several wraps of Teflon tape with a bead of silicone at the top.

It's working fine now, except for a small drip. I guess I will just lay some more silicone over the one leaking spot.

Thanks

Aaron

 

[setsailsoon]

You may want to look very closely at that leak. I've seen this a couple of times and it turned out to be a hairline crack that was barely visible until you pressure up. Take a very close up photo and then zoom in. This is more common with fiberglass pump housings. I have some photos in one of my posts a year or two ago that show this. I'll try to dig them up.

Chris

 

[aarogb]

@setsailsoon Here is a video of the leak:


Leak Video

I put another thick bead of Silicone on this morning and the leak is still there. Right now, the pump is priming fine and everything else seems good to go. However, I would like to get rid of this leak eventually.

 

[duraleigh]

It seems like you are trying to seal the leak from outside.......that won't work.

You must take the joint apart and clean ALL the old stuff off. Then evenly coat both male and female threads (you really don.t need much) and screw it back together.

 

[setsailsoon]

I would take the fitting apart, clean it up and take photos close up of the edges then zoom in and look for cracks... if you don't find anything do what Dave says above. Silicone's bond is just not strong enough to contain a leak when applied to outside.

 

[1poolman1]

OK guys, still having issues. There is no longer a leak at the union after I put a new one on. However, this threaded connection is going to be the death of me. Now it's leaking more than when I used just Teflon tape. Here are some pics of what it looks like:

View attachment 414010


View attachment 414011


View attachment 414014

Not sure what else I can try? I have checked the threads both in the pump and in the adapter and they all seem good. Nothing broken.

Thanks

Aaron

Running those male fittings all the way in as has been done can easily form a very small crack in the pump housing.

 

[setsailsoon]

There is another failure mechanism for this connection that we have not mentioned. White PVC pipe connectors cannot tolerate high temperature that comes from running the pump dry. This deforms the threads and you can't seal them after this happens. A better connector to use is gray pipe or one of the black high temperature connectors. There is a good video of this on YouTube.

After I repaired my cracked pump housing I used gray pipe and never had this problem again.

Chris