Just replaced locking nut on a Hayward C1200, and the lid won't close

nvanprooyen

New member
Feb 29, 2020
4
Orlando, FL
This person was having the same exact issue I am:


I just replaced the locking nut on Hayward C1200 cartridge filter but cannot get the lid back on. The lid does not make a seal anymore- seems that the brass fitting is too long but is the same size as the original. I replaced it because the threads in the old brass fitting were nearly stripped and the pressure blew the top off a couple days ago...

All I can think of is the threads in the old lock brass fitting were stripped about half way into the fitting so the tie rod went deeper into the fitting before, which allowed the lid to come down further. I can't even get the o ring on the lid into the main body of the filter container.I also tried using a pipe wrench to tighten the tie rod into the base of the cartridge body but it only turned a half turn. Threads on the top of tie rod look good.

The replacement part should be correct - CX900G. There is quite a bit of threading on the top of the rod, and it seems like when fully tightened the locking nut is only using maybe 1/3rd of it. I'm tempted to get out a hacksaw and cut the rod down. I'm pretty sure that would resolve the issue, given the additional threading. But I really don't want to do that if it's not necessary.

Any ideas?

Many, many thanks in advance!
 
Welcome! :wave: Well, you do appear to have the correct part according to THIS LINK from InyoPools. I may not be much help because I personally have not had to replace the knob on mine (yet), only the e-clip underneath (2Xs). I'm wondering if you might need to replace the entire CONE KIT to ensure a good fit? I do know that even by just changing the e-clips before under the cone, if everything wasn't just exactly right (tight fit), it wouldn't go back together. I'd hate to see you cut the rod only to go "oops" later. :hammer: Maybe give InyoPools a quick call to see if they know a trick to help get that thing to seat better?
 
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Welcome! :wave: Well, you do appear to have the correct part according to THIS LINK from InyoPools. I may not be much help because I personally have not had to replace the knob on mine (yet), only the e-clip underneath (2Xs). I'm wondering if you might need to replace the entire CONE KIT to ensure a good fit? I do know that even by just changing the e-clips before under the cone, if everything wasn't just exactly right (tight fit), it wouldn't go back together. I'd hate to see you cut the rod only to go "oops" later. :hammer: Maybe give InyoPools a quick call to see if they know a trick to help get that thing to seat better?
Hi, and thanks for the welcome! I did end up replacing the entire cone kit while I was at it. Everything was pretty old and needed to be replaced (washers, e-clip, etc). Everything seems to fit nice and tight. Shrug. No idea. Thanks for the advice to call Inyo before I cut the rod. I guess the worst case scenario if I do cut it, I could always buy another one if I mess something up. Quickly running ideas though, lol. One thing to note, it's not just a little off. I'd say a solid 1/2", if not more.

Thanks again!
 
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One thing to note, it's not just a little off. I'd say a solid 1/2", if not more.
That's is odd. You probably already checked to ensure the steel rod was fully seated in the base, so I'm at a loss as well. Half an inch is a big difference. Let us know what you come up with. I'm curious too.
 
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That's is odd. You probably already checked to ensure the steel rod was fully seated in the base, so I'm at a loss as well. Half an inch is a big difference. Let us know what you come up with. I'm curious too.
Yep, pretty weird. I did check the rod as well, tightened it really hard and it maybe turned 1/4 - 1/2 turn. Definitely nearly not enough to compensate for the gap.

Question for you: When you are putting the lid on the filter, how far does it push down before you begin tightening the locking nut? Before I replaced this, the lid would fully seat on the bottom half, all the way past the o-ring (the plastic ridges from the top and bottom touching). Then I'd tighten up the locking nut, get it snug, and good to go. Is that how far it goes down on yours before you begin tightening?
 
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Question for you: When you are putting the lid on the filter, how far does it push down before you begin tightening the locking nut?
In my case, when I rest the top-half on the steel rod, there's a small gap between the top & bottom halves - maybe about 1/4 inch or so. It definitely does not rest on the center O-ring until I tighten. Only after I begin turning the knob does the top-half begin to pull-down on top of the O-ring and lower half.
 
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In my case, when I rest the top-half on the steel rod, there's a small gap between the top & bottom halves - maybe about 1/4 inch or so. It definitely does not rest on the center O-ring until I tighten. Only after I begin turning the knob does the top-half begin to pull-down on top of the O-ring and lower half.
Thank you. This was helpful.

I managed to get this figured out. I think what was happening before, was since the threads were stripped, the rod pushed further up into the locking nut and it was only using a small fraction of the threads on the rod to tighten it up. Upon further inspection of the threads on the rod, there was a lot of stuff caked in there after getting past the part where the threads were being used previously (past the first 1/2 - 3/4" or so). Thoroughly cleaned the crud out of the threads with a wire brush, and now it screws down and seats properly. Doh! Turned it on and no leaks :)
 
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full
 
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Thank you. This was helpful.

I managed to get this figured out. I think what was happening before, was since the threads were stripped, the rod pushed further up into the locking nut and it was only using a small fraction of the threads on the rod to tighten it up. Upon further inspection of the threads on the rod, there was a lot of stuff caked in there after getting past the part where the threads were being used previously (past the first 1/2 - 3/4" or so). Thoroughly cleaned the crud out of the threads with a wire brush, and now it screws down and seats properly. Doh! Turned it on and no leaks :)
Know this is an old thread but I had same issue, couldn’t close the lid after installing new knob. Cleaning threads at the top did the trick. Guess they weren’t an issue with the old knob since those threads were so stripped. Thanks!
 

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