Part # 4663-09
Manufacturer Code CX1750G
Dimensions 6" L x 4" W x 3.25" D
Hayward® Star-Clear Plus™ Filter Locking Knob – CX1750G
For C1750 & C1900 Series Filters
Key Benefits
✅ OEM Replacement — Genuine Hayward® part designed for Star-Clear Plus™ cartridge filters
✅ Secures Filter Lid — Locks the top cover to the filter body for safe, leak-free operation
✅ Durable Construction — Built from corrosion-resistant materials for long service life
✅ Tool-Free Design — Easy hand-tightening, no special tools required
Why Choose This Locking Knob?
✅ Ensures a proper seal between lid and tank for safe filtration
✅ Simple replacement part — restores functionality if original knob is damaged or lost
✅ Built to Hayward® standards for fit, safety, and reliability
Tech Tips
⚠️ Always release filter pressure before loosening or removing the knob
✅ Hand-tighten only — over-tightening can damage threads or the filter lid
⚠️ Inspect O-ring/gasket under lid regularly; replace if worn to prevent leaks
Compatibility
✅ Hayward® Star-Clear Plus™ C1750 filters
✅ Hayward® Star-Clear Plus™ C1900 filters
❌ Not compatible with other Hayward® filter series (use correct locking knob for those models)
Specifications
✅ Part Number: CX1750G
✅ Filter Series: Star-Clear Plus™ (C1750, C1900)
✅ Function: Locking knob for securing filter lid
✅ Material: Reinforced polymer with threaded insert
What’s Included
✅ One Locking Knob – CX1750G
❌ Filter tank, lid, or O-rings (sold separately)
Does this part also include the gasket that is located between the top of the neck and under the black knob section? Or will that need to be purchased separately?
Reply
how do you remove the lock ring that holds the cx1750g lock knob on?
Reply
Hi, Jim. You will have to use a flat head screwdriver to remove the stainless steel clip that secures the knob to the lid. Then the knob will slide out of the Lid.
Reply
What is the thread size 5/8" or 1/2" ?will this fit haywood C12002 filter ?what is the length?
Reply
Pool filter top completely separated from the cartridge casing. The top was screwed on tightly but when I turned the pump back on it blew within seconds. could there be a valve closed causing an excessive amount of pressure
Reply
Hi, Bill. Not likely. The knob may have gotten stripped causing it not to fit securely to the Rod. Inspect the knob, rod and the filter casing thoroughly to find out where the issue is.
Reply
Less than 1 hr
Screwdriver
1 0
opened the filter cartridge assembly
inverted the housing top.
Removed the ring holding the locking knob in place.
Extracted the old knob by pulling upward while turning back and forth.
Added a new o-ring to the locking knob.
applied silicone grease.
Placed a washer on the knob shaft
Inserted the knob into place.
Placed a washer on the shaft inside the filter cartridge.
Used a screw driver to slip the keeper ring back in place.
Reassembled the cartridge housing.
The Most Recent Reviews
(4 out of 5 stars) Pool filter parts
Reviewed By: George G. from Palmyra, VA ()
Product was as advertised and was installed with minimal effort. Price was reasonable and quality was satisfactory.
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(5 out of 5 stars)
Reviewed By: papa ()
Pros: this product was perfect for my filter it worked great
Cons: none
this product was a perfect match for my filter and it works great
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