PD40SL / C-7402 / FC-4010
40 sq ft replacement filter cartridge • 7″ OD × 9.125″ long
The 40-square-foot Doughboy cartridge, the PD40SL, is 7 inches across and about 9 inches tall, with the same closed molded-knob top as the rest of the Doughboy line. Doughboy's number is 2396-040, and the cross-references are Unicel C-7402 and Filbur FC-4010. This is the one Doughboy size that has a Filbur listing. Because all the Doughboy cartridges share a 7-inch diameter, height separates the 20, 40, 60, and 90, so measure your old element end to end rather than guess. This mid-size cartridge suits a typical medium above-ground pool. Step up to the 60 or 90 if you're running a bigger one.
Compare on Amazon
PD40SL replacements on Amazon
The buttons below pull up Amazon results for each cross-reference part number. Same physical cartridge, different stickers, often different prices. Cross-shop and pick the cheapest option that has solid recent reviews.
Cross-Reference & Interchangeable Part Numbers
| Brand | Part Number | Type |
|---|---|---|
| Pleatco | PD40SL | Primary |
| Unicel | C-7402 | Equivalent |
| Filbur | FC-4010 | Equivalent |
| OEM | Doughboy 2396-040 | Original Equipment |
Always verify dimensions and end-cap type before purchasing a replacement.
Compatible Pool Filter Systems
| Brand | Model |
|---|---|
| Doughboy | 40 sq ft Pool Filter |
Frequently Asked Questions
What are the dimensions of the PD40SL?
The PD40SL is 7 inches in outer diameter, 9.125 inches long, with a closed top and an open bottom. Total filtration area is 40 square feet. Before ordering, pull your existing cartridge and measure it yourself, or check the label inside the housing. OD and length both have to match within about an eighth of an inch, and the end-cap style needs to match exactly so the cartridge seats properly when the lid closes.
What other part numbers are interchangeable with the PD40SL?
PD40SL is the same physical cartridge as C-7402, FC-4010, plus OEM versions like Doughboy 2396-040. Same dimensions (7" × 9.125"), same closed top, same open bottom. The Pleatco, Unicel, and Filbur boxes ship the same media inside, just with different stickers. The only thing to watch is the end-cap style: if a cross-reference has a slightly different cap design, it may not seat right in your housing.
Is the Doughboy 2396-040 the same filter as the PD40SL?
Yes. Doughboy 2396-040 is an OEM number, the code the tub or pool builder stamps on the cartridge they ship. The filter itself is made by Pleatco, Unicel, or Filbur, so Doughboy 2396-040 and PD40SL, C-7402, FC-4010 all point to one interchangeable cartridge. Buy whichever is cheapest with solid recent reviews, and just check that the dimensions match your old cartridge before you order.
How often should I replace the PD40SL?
At 40 sq ft the PD40SL runs smaller than the big 100-plus sq ft pool cartridges, so it has less buffer between cleanings. Expect 12 to 18 months in normal use, less if the pool sees heavy traffic or the chemistry drifts. Watch the gauge: when pressure sits 8 to 10 psi above the clean starting point and a soak won't drop it, put in a fresh one.
How do I clean the PD40SL?
The PD40SL has a closed (solid) top cap, so water enters through the side and drains through the bottom only. Pull the cartridge from the housing and hose it down. Hit the pleats from above at about a 45-degree angle so water rinses debris out instead of packing it deeper, and work top to bottom while rotating the cartridge. Skip the pressure washer. The high pressure tears or collapses pleats, and once that happens you've lost media that doesn't come back. Every few months, give it a deeper clean: soak in a dedicated pool filter cleaner per the product's dwell time, then rinse it down completely before reinstalling. Keeping a spare cartridge on the shelf is genuinely worth it. You swap, run the soak overnight, and the pool keeps filtering.
Which hot tubs and spas use the PD40SL?
Pull your existing cartridge and read the part number off the end cap, or check the label inside the filter compartment. That's the most reliable way to confirm compatibility.
Dimensions
Specifications
| Outer Diameter | 7″ |
|---|---|
| Length | 9.125″ |
| Top Type | Closed (solid end cap) |
| Bottom Type | Open (no end cap) |
| Filtration Area | 40 sq ft |
| Primary Brand | Pleatco |
| Part Number | PD40SL |
Fitment notes
Injection molded knob/closed top. Doughboy 40 sq ft pool filter.