Hayward Cartridge Filter Locking Knob Repair

Texas Splash

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Jun 22, 2014
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Texas, San Antonio/Marion, South-Central Area
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Chlorine
Salt Water Generator
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CircuPool RJ-45 Plus
(UPDATED 11 Mar 2021) The following was used on my Hayward C1200, but may also apply to other Hayward-series cartridge filters that utilize the locking knob on top. These procedures should help those who find that their locking knob on top doesn't seem to fully disengage from the threaded rod inside the filter. Thus, it may seem like the top part of the filter is still stuck to the bottom, or that the knob is released from the rod when actually it is not.

Common problem: The retaining ring (e-clip) that holds the knob tightly against the top housing has rusted apart, therefore it is not fully seated on the knob shaft and/or allows the knob to just spin on the rod inside.

Objective #1 - Get that top part of the housing off. That takes some patience. I used a continuous pulling action as I tried to turn the knob counterclockwise to help disengage it from the inside rod. Even then it still felt stuck. If that doesn't work, you may try the opposite by keeping "downward" pressure on the knob as you unscrew it. Then I grabbed the top house housing near its bottom "lip" which helped give me leverage to pull stronger and remove it.

Here is a pic of the inside of the housing. Notice the white concave shell that guides the top portion over the rod. To remove it, simply insert your finger into the small hole and pull firmly. It should pop out. If stuck, use some pliers on the outer lip and gently pull it off.


Next image you see one of the nylon washers and what's left of my rusted retaining ring (e-clip).


Now you need to purchase a new one-inch "e-clip". Below is one I got from Lowe's (2-pack) for about $1.50 (P/N 881403). But that steel e-clip should only be used temporarily to get your filter back on as the steel will rust too fast.



Ideally you want a stainless steel e-clip. If you shop on-line you'll find some pool stores selling this e-clip for about $11. HERE is an e-clip from Amazon for about $11.00. I opted for the e-clip you see below from McMasters-Carr. While I had to pay shipping of about $10.00, each clip was only a little over $2.00, so I got two of them for about $15.00.



After you wipe-off the area inside, you'll slip the nylon washer back into position. Make sure the locking knob is fully pressed down "into" the housing so the stem is protruding inside as much as it will go. You need access to the tiny grove at the end of that stem so you can slip the new e-clip into place. If you find that the groove at the end of the handle stem is clogged with rust, remove the knob assembly in its entirety to clean-out the groove so it will accept a new e-clip. Lube everything well with pool silicone when you put it back together.



The e-clip holds the nylon washer in-place and also keeps the locking knob pulled-in tightly inside the housing. It may seem a bit tricky to squeeze that e-clip back on, but some needle nose pliers should help. The video below will show you how.

Once done, it should look like this:



I think that about covers it. Good luck!
 
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So....The locking knob is supposed to stay attached to the filter lid? I kept thinking when I unscrewed it from the rod that it was supposed to come off.....Then I would lift the lid off the filter etc. I thought mine, being permanently attached to the lid, was an anomaly?

My E-Ring is in fine shape (not rusty) and apparently firmly attached to the bottom of the locking knob.......Maybe I just need to grease it?
 
Yes, the black locking knob stays attached to the top of the housing. But it should be pressed firmly all the way flush at the top (no slack). If everything looks good, then yes, you may want to apply some lube. You could pull-out the white convex cone and dab some lube to the bottom of the knob. I also like to put some lube on the threaded end of the rod so I know it's getting inside the knob from the bottom and into the female threaded portion.
 
Could you buy a bolt with the same threads as the tie rod and insert into the locking knob to see that it's not stripped. By using some lubricant it could clean up the threads
I suppose you could. At least with the top of the filter housing off, it's a little easier to work with.
 
Many thanks. With your help and clear pictures it took me no time to fix the problem. Another thread suggested that the top of the filter housing will pop off when the pump is turned on -- and it did :) . The nylon washer and the eclips had come loose and was inside the housing. After that it was an easy fix. Now..what to do with the replacement locking knob that I ordered yesterday :-(
 
Hi. First time member. My top also gets stuck. I used the water pressure from turning the pump on to get it off. My e-ring is not rusted and seems to be firmly in place. Yet, I am able to wiggle the white washer with a finger. I can also slightly rock the knob from side to side, but just a little. Any suggestions?
 
Hi. First time member. My top also gets stuck. I used the water pressure from turning the pump on to get it off. My e-ring is not rusted and seems to be firmly in place. Yet, I am able to wiggle the white washer with a finger. I can also slightly rock the knob from side to side, but just a little. Any suggestions?
Hello Tgel1972! :wave: So I'm not understanding … what's the issue specifically? You have the top half off right? Are you trying to take the parts underneath apart? Pull-off the white spacer/cap, remove the e-clip, etc?

"neptunes", I'm glad you got it fixed. :goodjob:
 

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Thanks for posting. My C1200 filter top blew off this weekend - threads on the locking knob were stripped out. Ordered a new knob and washer/o-ring kit and replaced today - your vid was very helpful and saved me some $$$. Cheers!
 
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