Baldwin Filters · Form 561 Interchange · inline line
PT9139 filter element: specifications & equivalents
The PT9139 is a Baldwin Filters inline-line hydraulic filter element. Verify against the current manufacturer data sheet before ordering.
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. | PT9139 |
| 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 |
|---|---|---|---|
|
↔ FISH77596 page in verification queue | Aftermarket | partial | Baldwin's Form 561 Number-Finder cross-reference lists FISH77596 (HIFI/JURA FILTRATION) as replaced by Baldwin PT9139. Form/fit listing without published performance data — verify micron grade, collapse rating and seal configuration before substituting. |
| ↔ HD9210 | MANN-FILTER | partial | MANN-FILTER's online catalog lists PT9139 (BALDWIN) as a comparison number for HD9210. 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 PT9139 model number is decoded
- PT9139Baldwin 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 PT9139 filter element?
How do I read the PT9139 part number?
Is a same-envelope aftermarket element always a drop-in replacement?
How often should a hydraulic return-line element be replaced?
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.