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PERMCO BACK UP RING

Description & Features

Designed for use in Permco hydraulic gear pumps and motors, this Back Up Ring is a genuine OEM sealing component used to support and protect primary seals under pressure. Back up rings of this type are typically installed alongside O-rings to prevent extrusion in high-pressure hydraulic circuits, maintaining seal integrity across demanding duty cycles.

As a Permco-sourced part, the Permco Back Up Ring is matched to original equipment tolerances, making it a reliable choice for maintenance, rebuild, and replacement applications on compatible Permco units.

SKU: 947-00374-WBR

Supplier Part Number (MPN): 947-00374-WBR

Specifications

Brand Permco	Suitable For Use With 197 Series Counterclockwise Hydraulic Gear Pumps

Product Questions & Answers (2)

Question by: Shane W on Oct 16, 2025, 7:52 PM

got a Permco gear pump apart right now. what’s this back up ring actually doing in there?

Answer by: Customer Support on Oct 18, 2025, 11:04 AM

In a Permco hydraulic gear pump or motor, the back up ring sits with an O-ring and helps keep that primary seal from extruding when pressure spikes. It is there to support the seal so it holds its shape and keeps sealing through tougher duty cycles.

Question by: Floyd B on Apr 9, 2025, 11:26 AM

rebuilding a permco gear pump and need to know if this back up ring is a genuine oem part or one of them aftermarket knockoffs

Answer by: Customer Support on Apr 11, 2025, 6:06 AM

Genuine Permco OEM is exactly what this is. It's sourced directly from Permco and made to original equipment tolerances, so it'll fit and function the same as what came out of the pump when it was new. For a rebuild, that matters a lot more than folks sometimes realize, especially when you're trying to get a good seal the first time around.