Fleetguard · HF Hydraulic · return line
HF6684 filter element: specifications & equivalents
The HF6684 is a Fleetguard return-line hydraulic filter element, sized 121.67 × 364.69 mm OD × length, rated at 12.2 µm absolute (12.2 µm at β75(c); 15.1 µm at β200(c) per ISO 16889). Verify against the current manufacturer data sheet before ordering.
Envelope OD × L 121.67 × 364.69 mm
Filtration rating 12.2 µm abs.
Beta rating 12.2 µm at β75(c); 15.1 µm at β200(c) per ISO 16889
Line type return
Catalog verified. Parameters extracted from the manufacturer’s electronic
catalog / official interchange document and checked 2026-09-28. Confidence score 0.90.
Specifications and cross-references are taken from the Fleetguard online catalog API. Where both TWA and Beta ratings are published the conventions differ — verify cleanliness targets, collapse rating and seal configuration against the current Fleetguard data sheet before ordering.
Specification table
| Parameter | Value |
|---|---|
| Filter type | return line |
| Filtration rating | 12.2 µm |
| Rating basis | absolute |
| Beta ratio | 12.2 µm at β75(c); 15.1 µm at β200(c) per ISO 16889 |
| Outside diameter OD | 121.67 mm |
| Length | 364.69 mm |
| End caps | spin-on baseplate with attached gasket |
| Flow direction | outside-in |
| Integral bypass valve | none (housing/valve-dependent) |
| Manufacturer part no. | HF6684 |
| Source catalog | Cummins Filtration / Fleetguard: Fleetguard online product catalog (fleetguard.com) |
| Last verified | 2026-09-28 |
Sources: Cummins Filtration / Fleetguard — Fleetguard online product catalog (fleetguard.com) — accessed 2026-09-28.
Fleetguard® and all model designations are trademarks of their respective owners, used here for identification only — ElementRef is an independent reference site, not an authorized Fleetguard distributor.
Dimensions & series range
| Outside diameter | 121.67 mm (4.790 in) |
| Overall length | 364.69 mm (14.358 in) |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
|
↔ 1281850H1 page in verification queue | Aftermarket | partial | Fleetguard's online catalog lists 1281850H1 as an interchange for HF6684. Envelope cross-reference; verify micron grade, collapse rating and seal configuration before substituting. |
|
↔ 1526901 page in verification queue | UFI | partial | Fleetguard's online catalog lists 1526901 as an interchange for HF6684. Envelope cross-reference; verify micron grade, collapse rating and seal configuration before substituting. |
|
↔ 1526902 page in verification queue | UFI | partial | Fleetguard's online catalog lists 1526902 as an interchange for HF6684. Envelope cross-reference; verify micron grade, collapse rating and seal configuration before substituting. |
|
↔ 1535370 page in verification queue | UFI | partial | Fleetguard's online catalog lists 1535370 as an interchange for HF6684. Envelope cross-reference; verify micron grade, collapse rating and seal configuration before substituting. |
|
↔ 1729 page in verification queue | Aftermarket | partial | Fleetguard's online catalog lists 1729 as an interchange for HF6684. Envelope cross-reference; verify micron grade, collapse rating and seal configuration before substituting. |
|
↔ 191728C1 page in verification queue | Aftermarket | partial | Fleetguard's online catalog lists 191728C1 as an interchange for HF6684. Envelope cross-reference; verify micron grade, collapse rating and seal configuration before substituting. |
|
↔ 1971728C1 page in verification queue | Aftermarket | partial | Fleetguard's online catalog lists 1971728C1 as an interchange for HF6684. Envelope cross-reference; verify micron grade, collapse rating and seal configuration before substituting. |
|
↔ 277311A1 page in verification queue | Aftermarket | partial | Fleetguard's online catalog lists 277311A1 as an interchange for HF6684. Envelope cross-reference; verify micron grade, collapse rating and seal configuration before substituting. |
|
↔ 366387 page in verification queue | Aftermarket | partial | Fleetguard's online catalog lists 366387 as an interchange for HF6684. Envelope cross-reference; verify micron grade, collapse rating and seal configuration before substituting. |
|
↔ 3663870 page in verification queue | UFI | partial | Fleetguard's online catalog lists 3663870 as an interchange for HF6684. Envelope cross-reference; verify micron grade, collapse rating and seal configuration before substituting. |
| ↔ 51729 | WIX Filters | partial | Fleetguard's online catalog lists 51729 as an interchange for HF6684. Envelope cross-reference; verify micron grade, collapse rating and seal configuration before substituting. |
|
↔ 534039D1 page in verification queue | Aftermarket | partial | Fleetguard's online catalog lists 534039D1 as an interchange for HF6684. Envelope cross-reference; verify micron grade, collapse rating and seal configuration before substituting. |
|
↔ 551729 page in verification queue | Aftermarket | partial | Fleetguard's online catalog lists 551729 as an interchange for HF6684. Envelope cross-reference; verify micron grade, collapse rating and seal configuration before substituting. |
| ↔ 57866 | WIX Filters | partial | Fleetguard's online catalog lists 57866 as an interchange for HF6684. Envelope cross-reference; verify micron grade, collapse rating and seal configuration before substituting. |
|
↔ 718573 page in verification queue | Aftermarket | partial | Fleetguard's online catalog lists 718573 as an interchange for HF6684. Envelope cross-reference; verify micron grade, collapse rating and seal configuration before substituting. |
|
↔ 85729 page in verification queue | Aftermarket | partial | Fleetguard's online catalog lists 85729 as an interchange for HF6684. Envelope cross-reference; verify micron grade, collapse rating and seal configuration before substituting. |
|
↔ 86040230 page in verification queue | UFI | partial | Fleetguard's online catalog lists 86040230 as an interchange for HF6684. Envelope cross-reference; verify micron grade, collapse rating and seal configuration before substituting. |
| ↔ 9.05.14MA10BN | HYDAC | partial | Fleetguard's online catalog lists 90514MA10BN as an interchange for HF6684. Envelope cross-reference; verify micron grade, collapse rating and seal configuration before substituting. |
|
↔ 92729 page in verification queue | Aftermarket | partial | Fleetguard's online catalog lists 92729 as an interchange for HF6684. Envelope cross-reference; verify micron grade, collapse rating and seal configuration before substituting. |
|
↔ 944041Q page in verification queue | Aftermarket | partial | Fleetguard's online catalog lists 944041Q as an interchange for HF6684. Envelope cross-reference; verify micron grade, collapse rating and seal configuration before substituting. |
|
↔ 944046Q page in verification queue | Aftermarket | partial | Fleetguard's online catalog lists 944046Q as an interchange for HF6684. Envelope cross-reference; verify micron grade, collapse rating and seal configuration before substituting. |
|
↔ BT742 page in verification queue | Aftermarket | partial | Fleetguard's online catalog lists BT742 as an interchange for HF6684. Envelope cross-reference; verify micron grade, collapse rating and seal configuration before substituting. |
| ↔ BT8870-MPG | Baldwin Filters | partial | Fleetguard's online catalog lists BT8870MPG as an interchange for HF6684. Envelope cross-reference; verify micron grade, collapse rating and seal configuration before substituting. |
| ↔ BT8870-MPG | Baldwin Filters | partial | Baldwin's Form 561 Number-Finder cross-reference lists HF6684 (FLEETGUARD) as replaced by Baldwin BT8870-MPG. Form/fit listing without published performance data — verify micron grade, collapse rating and seal configuration before substituting. |
|
↔ CPK1531 page in verification queue | Aftermarket | partial | Fleetguard's online catalog lists CPK1531 as an interchange for HF6684. Envelope cross-reference; verify micron grade, collapse rating and seal configuration before substituting. |
|
↔ H65027 page in verification queue | Aftermarket | partial | Fleetguard's online catalog lists H65027 as an interchange for HF6684. Envelope cross-reference; verify micron grade, collapse rating and seal configuration before substituting. |
|
↔ HC130 page in verification queue | Pall | partial | Fleetguard's online catalog lists HC130 as an interchange for HF6684. Envelope cross-reference; verify micron grade, collapse rating and seal configuration before substituting. |
|
↔ HF0668400 page in verification queue | Fleetguard | partial | Fleetguard's online catalog lists HF0668400 as an interchange for HF6684. Envelope cross-reference; verify micron grade, collapse rating and seal configuration before substituting. |
|
↔ HF936 page in verification queue | Fleetguard | partial | Fleetguard's online catalog lists HF936 as an interchange for HF6684. Envelope cross-reference; verify micron grade, collapse rating and seal configuration before substituting. |
|
↔ HY378W page in verification queue | Aftermarket | partial | Fleetguard's online catalog lists HY378W as an interchange for HF6684. Envelope cross-reference; verify micron grade, collapse rating and seal configuration before substituting. |
|
↔ LFH8417 page in verification queue | Aftermarket | partial | Fleetguard's online catalog lists LFH8417 as an interchange for HF6684. Envelope cross-reference; verify micron grade, collapse rating and seal configuration before substituting. |
|
↔ P166909 page in verification queue | Donaldson | partial | Fleetguard's online catalog lists P166909 as an interchange for HF6684. Envelope cross-reference; verify micron grade, collapse rating and seal configuration before substituting. |
|
↔ P170665 page in verification queue | Donaldson | partial | Fleetguard's online catalog lists P170665 as an interchange for HF6684. Envelope cross-reference; verify micron grade, collapse rating and seal configuration before substituting. |
| ↔ P170949 | Donaldson | partial | Fleetguard's online catalog lists P170949 as an interchange for HF6684. Envelope cross-reference; verify micron grade, collapse rating and seal configuration before substituting. |
|
↔ P8463 page in verification queue | Donaldson | partial | Fleetguard's online catalog lists P8463 as an interchange for HF6684. Envelope cross-reference; verify micron grade, collapse rating and seal configuration before substituting. |
|
↔ PSH797 page in verification queue | Aftermarket | partial | Fleetguard's online catalog lists PSH797 as an interchange for HF6684. Envelope cross-reference; verify micron grade, collapse rating and seal configuration before substituting. |
|
↔ RE152658 page in verification queue | STAUFF | partial | Fleetguard's online catalog lists RE152658 as an interchange for HF6684. Envelope cross-reference; verify micron grade, collapse rating and seal configuration before substituting. |
|
↔ RE174130 page in verification queue | STAUFF | partial | Fleetguard's online catalog lists RE174130 as an interchange for HF6684. Envelope cross-reference; verify micron grade, collapse rating and seal configuration before substituting. |
|
↔ RE51797 page in verification queue | STAUFF | partial | Fleetguard's online catalog lists RE51797 as an interchange for HF6684. Envelope cross-reference; verify micron grade, collapse rating and seal configuration before substituting. |
|
↔ RE51797A page in verification queue | STAUFF | partial | Fleetguard's online catalog lists RE51797A as an interchange for HF6684. Envelope cross-reference; verify micron grade, collapse rating and seal configuration before substituting. |
|
↔ VPK1531 page in verification queue | Aftermarket | partial | Fleetguard's online catalog lists VPK1531 as an interchange for HF6684. Envelope cross-reference; verify micron grade, collapse rating and seal configuration before substituting. |
|
↔ WH12005 page in verification queue | Aftermarket | partial | Fleetguard's online catalog lists WH12005 as an interchange for HF6684. Envelope cross-reference; verify micron grade, collapse rating and seal configuration before substituting. |
|
↔ WOH211 page in verification queue | Aftermarket | partial | Fleetguard's online catalog lists WOH211 as an interchange for HF6684. Envelope cross-reference; verify micron grade, collapse rating and seal configuration before substituting. |
Interchange levels: full catalog-confirmed drop-in · partial verify parameters · verify manual confirmation required. Links resolve to the equivalent model's specification page where available.
How the HF6684 model number is decoded
- HF6684Fleetguard HF-series hydraulic spin-on filter part number.
- 364.69 mmOverall height.
- 121.67 mmLargest outside diameter.
- 12.2 µm at β75(c); 15.1 µm at β200(c) per ISO 16889Published efficiency ratings.
Typical equipment & applications
- Construction, agricultural and industrial hydraulic circuits
- Mobile-equipment hydraulic return and pressure lines
Selection pitfalls — read before you substitute
- A return-line element is not a pressure-line element: return cartridges (BN4HC low-collapse) tolerate roughly 20 bar differential, while BH4HC pressure executions are rated to 210 bar. Installing a low-collapse element in a pressure housing can rupture the media on cold-start spikes.
- This element has no integral bypass — opening pressure is set by the housing’s reusable bypass valve. Confirm the valve setting (commonly 3.4 bar) is present before fitting.
- “10 µm nominal” and “12 µm at β1000” can describe the very same media — one is reported at β≥200, the other at β≥1000 per ISO 16889. Compare ratings at the same Beta test point, not just the printed micron number.
- Nitrile (NBR) seals are standard for mineral hydraulic oil but fail early in some phosphate-ester fluids and at sustained high temperature; verify seal compound against the fluid data sheet (fluorocarbon/Viton executions may be required).
- End-cap geometry and the number/position of O-rings block interchange even when OD and length match — visually compare end caps before fitting, especially with aftermarket cartridges.
Frequently asked questions
What are the dimensions of the HF6684 filter element?
The published envelope is 121.67 mm OD × 364.69 mm length (4.790 × 14.358 in). Confirm against the housing drawing before ordering.
What micron rating does HF6684 use?
This element is rated 12.2 µm absolute — 12.2 µm at β75(c); 15.1 µm at β200(c) per ISO 16889. Always compare Beta ratings at the same test point: two brands may print different micron numbers for the same physical grade.
What replaces the HF6684 filter element?
43 partial match(es) requiring parameter review
How do I read the HF6684 part number?
See the designation decoder above: each segment of HF6684 encodes size, line type, filtration grade and media/collapse execution.
Is a same-envelope aftermarket element always a drop-in replacement?
No. Matching OD and length only proves the cartridge fits the bowl. End-cap style, seal compound, micron/Beta rating, collapse pressure and bypass configuration must also match; the table above tags every equivalent as full, partial or verify for exactly this reason.
How often should a hydraulic return-line element be replaced?
Replace at the housing manufacturer’s recommended differential-pressure setting (commonly signalled by a clogging indicator), or on a time-based service interval when no indicator is fitted — never wait for bypass to open continuously, because unfiltered oil then reaches the valves.
Other models in the HF Hydraulic series
All 2621 →Reviewed & verified by the ElementRef engineering desk against Cummins Filtration / Fleetguard on 2026-09-28. Read our editorial & correction policy.