Baldwin Filters · Form 561 Interchange · inline line
PT23178 filter element: specifications & equivalents
The PT23178 is a Baldwin Filters inline-line hydraulic filter element. Verify against the current manufacturer data sheet before ordering.
Line type inline
Partially verified. Fit and grade trace to an official interchange document;
dimensional values are compiled from 0 aftermarket listing(s)
and must be confirmed against the manufacturer housing drawing. Confidence score 0.80.
Form 561 is a cross-reference only — Baldwin prints no dimensions, micron rating, collapse pressure or seal data for this part number here. Verify every specification against the current Baldwin data sheet before ordering.
Specification table
| Parameter | Value |
|---|---|
| Filter type | inline line |
| Integral bypass valve | none (housing/valve-dependent) |
| Manufacturer part no. | PT23178 |
| Source catalog | Baldwin Filters: Baldwin Filters Form 561 |
| Last verified | 2026-09-30 |
Sources: Baldwin Filters — Baldwin Filters Form 561 — accessed 2026-09-30.
Baldwin Filters® and all model designations are trademarks of their respective owners, used here for identification only — ElementRef is an independent reference site, not an authorized Baldwin Filters distributor.
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
|
↔ 100S125WB02 page in verification queue | Aftermarket | partial | Baldwin's Form 561 Number-Finder cross-reference lists 100S125WB02 (HYDAC) as replaced by Baldwin PT23178. Form/fit listing without published performance data — verify micron grade, collapse rating and seal configuration before substituting. |
|
↔ FISH77032 page in verification queue | Aftermarket | partial | Baldwin's Form 561 Number-Finder cross-reference lists FISH77032 (HIFI/JURA FILTRATION) as replaced by Baldwin PT23178. Form/fit listing without published performance data — verify micron grade, collapse rating and seal configuration before substituting. |
|
↔ GFS133B7T125B page in verification queue | Aftermarket | partial | Baldwin's Form 561 Number-Finder cross-reference lists GFS133B7T125B (FILTREC) as replaced by Baldwin PT23178. Form/fit listing without published performance data — verify micron grade, collapse rating and seal configuration before substituting. |
| ↔ HF35170 | Fleetguard | partial | Fleetguard's online catalog lists PT23178 as an interchange for HF35170. Envelope cross-reference; verify micron grade, collapse rating and seal configuration before substituting. |
|
↔ MSZ302BMCVB10 page in verification queue | Aftermarket | partial | Baldwin's Form 561 Number-Finder cross-reference lists MSZ302BMCVB10 (SOFIMA) as replaced by Baldwin PT23178. Form/fit listing without published performance data — verify micron grade, collapse rating and seal configuration before substituting. |
|
↔ MSZ302BMNB page in verification queue | Aftermarket | partial | Baldwin's Form 561 Number-Finder cross-reference lists MSZ302BMNB (SOFIMA) as replaced by Baldwin PT23178. Form/fit listing without published performance data — verify micron grade, collapse rating and seal configuration before substituting. |
|
↔ ONSTR0863BG1M90 page in verification queue | Aftermarket | partial | Baldwin's Form 561 Number-Finder cross-reference lists ONSTR0863BG1M90 (MP FILTRI) as replaced by Baldwin PT23178. Form/fit listing without published performance data — verify micron grade, collapse rating and seal configuration before substituting. |
|
↔ SFE100G125A10BYP page in verification queue | Aftermarket | partial | Baldwin's Form 561 Number-Finder cross-reference lists SFE100G125A10BYP (HYDAC) as replaced by Baldwin PT23178. Form/fit listing without published performance data — 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 PT23178 model number is decoded
- PT23178Baldwin filter part number per the Form 561 Number-Finder cross-reference.
Typical equipment & applications
- Hydraulic / transmission filtration — listed in the Baldwin Form 561 Number-Finder cross-reference.
Selection pitfalls — read before you substitute
- “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 replaces the PT23178 filter element?
8 partial match(es) requiring parameter review
How do I read the PT23178 part number?
See the designation decoder above: each segment of PT23178 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 Form 561 Interchange series
All 1208 →Reviewed & verified by the ElementRef engineering desk against Baldwin Filters on 2026-09-30. Read our editorial & correction policy.