DRAIN PLUG NO LONGER STAYS SECURE IN HAYWARD PUMP. PROBLEM IS INTERNAL THREADS ARE WORN DOWN.

[who4ever]

I have an Hayward-Perflex EC-65 DE pump/filter for my 25K inground. My problem is one of the 2 drainplugs at the bottom of the pump will not stay in. It shoots out the side of the filter in much less than a minute. I can't say I've never had this problem before and a bag in the garage of worn out plugs makes me realize after 27 years that I have been way over-tightening the drainplugs all this time and now finally I have worn out the female threads within the pump. I'm sure I thought over-tightening was OK because I couldn't imagine Hayward make the female threads out of anything but stainless steel. It seems that the threads are just plastic though. Is that right? So now I have the female larger than the male. I tried smothering it in plumbers tape at when it happened during start-up but it blew out today-figure a 6-7 week repair. It's a good thing I was pretty close when the plug blew out today our I could have lost a ton of water and really messed up the pump and motor. So this is a problem I have to solve within 2-3 days or so, at most, because I had to turn the pump off.So from reading the internet I learned something about re-tapping the holw but then the hole would be way too large for the plug so then I'd need to find a larager plug, etc. etc. etc. That doesn't look like a good final outcome in my hands. I've read the plug could just be glued in place but I'd rather not for a couple of reasons. What I was thinking about is lining the female threads with Plastic Weld, wrapping one rotation of plumbers tape down tight around the plug so the threads are sharp and pushing it in or a little smear of Magic Lube. I thought maybe the layer of plumbers tape or the Magic Lube would still allow me to gently unscrew the plug when I needed to. Another meh because it still allows for the Plastic Weld to fail and the plug comes out when I'm not around. I was also thinking about using Epoxy putty instead of the Plastic Weld. Oh yeah, before I forget, if I chose to glue the plug in, should I take the O-ring off? It seems so because there will be no compression on the O-ring when I push the plug in. I was also wondering if it was possible to screw the plug in from the inside, therefore eliminating the problem of the plug flying out again. I appears from looking at the pump that once I took the motor off I would have access to the inside of the hole. But don't hold me to that one.

How would you people solve this? Thanks in advance, Dave

 

[mguzzy]

So is the plug in the Filter or the pump? those are two different gizmos entirely.. Have you tried putting some Teflon tape on it? I wouldn't do anything that essentially glues the plug in there. Also post some pics if you can.. It much easier to see what you're talking about with a pic!

 

[who4ever]

The plug that has failed is in the pump not the filter. Tried with a lot of tape and it fails and is unreliable which is worse. Here are some pix. Thanks

 

[Newdude]

I had a buddy retap my sprinkler pump drain plug this spring. It was cast iron but the same general principle. It had been iffy at best for a few years and finally stripped. For all your aggravation that you will put yourself through doing a half fix, and then the big problem that ensues when it fails, hire a plumber to tap it for you.

 

[who4ever]

To what size, though? Tapping it means increasing the size of the plug hole, right? What do I tell the plumber? I don't know what the next largest size drain plug is and how fast I can get it? Remember, I am shut down because of this. Dave

 

[Newdude]

Tapping it means increasing the size of the plug hole, right? What do I tell the plumber

It will increase the plug hole and need a bigger plug. The plumber has some leeway in what size he uses based upon his tap set and available plugs. The plumber should have plugs. They will probably be bolt heads and not wing nut style, but if its secure, it doesnt matter.

 

[JamesW]

I would drill and tap the hole.

Use a drill bit that just removes the existing threads so that the hole is smooth. I think that a 37/64 drill bit should work.

Then, tap the hole with a thread that will work with the hole. I think that a 5/8”-18 thread will work.

Then, get a 5/8”-18 stainless steel screw, wrap it with some Teflon, add some sealant and screw it into the hole.

Verify the sizes to be sure.

The tap and drill set should be available at Home Depot or Lowe's. You should be able to do it. Just watch a few videos and then practice on a scrap piece of plastic to get the technique.

 

[JamesW]

I think that if you're careful, you could use a 7/16" drill bit to clean out the hole and then tap the existing threads with a 1/4" npt tap.

If you look in the hole, you can see a little bit of extra wall. Drill a little deeper with the 7/16" drill bit without hitting the existing threads. Then tap the existing threads a little deeper with the 1/4" npt tap. Then, use a long, brass 1/4' NPT plug with teflon and sealant to get a good deep thread lock. Don't cross-thread the tap in the existing threads. Make sure that the tap gets in the original threads.

The drill and tap set are available at Home depot, lowes or most hardware stores.

 

[Richard320]

Can you get inside at all? A bolt and nut with a compressible washer on the outside would seal it up.

 

[Dave_NJ]

You could also re-tap the threads with a helicoil insert. Basically you drill and tap a slightly larger hole and then insert the helicoil which will get you back to the original thread size.

Heli-Coil® Wire Insert Systems | Screw Threaded Inserts | STANLEY® Engineered Fastening

Heli-Coil® Wire Insert Systems | Screw Threaded Inserts | STANLEY® Engineered Fastening

www.stanleyengineeredfastening.com

You need to know the size and pitch of the existing plug and see if you can find the same helicoil insert size.

 

[who4ever]

Wow. Thank you all!

 

[sktn77a]

You could try an expanding butyl bilge plug first to see if that will hold but drilling and retapping the hole to take a bigger plug is the way to go for a permanent solution. I think helicoils are mostly used in iron and aluminum pump/engine applications.