Designed for hydraulic cylinder applications, the Hercules Piston Seal 5-1/2 In Od is a piston sealing solution manufactured by Hercules Sealing Products, a trusted name in fluid power sealing components. With a 5-1/2 inch outer diameter, this seal is sized for larger-bore hydraulic cylinders commonly found in heavy equipment, industrial machinery, and mobile hydraulic systems.
Hercules Sealing Products engineers piston seals for reliable performance under the dynamic conditions typical of reciprocating hydraulic cylinders, where maintaining consistent sealing integrity is critical to system function. This seal is a direct-fit replacement for applications referencing the supplier part number PSQ-88.
SKU: PSQ-88
Supplier Part Number (MPN): PSQ-88
Alternate Part Numbers: MI-08751838, MINO-00407X25584
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Specifications
Alternate Part Numbers
Alternate Part NumberMI-08751838, Alternate Part Number MINO-00407X25584
Brand
Hercules Sealing Products
Brand
Hercules Sealing Products
Pack Size
1.00
UOM
EA
Supplier Part Number
PSQ-88
Product Weight
0.17 lbs
Product Questions & Answers (3)
Question by: Shawn C on Mar 4, 2026, 9:27 PM
How durable is this thing for heavy machinery?
Answer by: Customer Support on Mar 6, 2026, 8:04 AM
Designed for hydraulic cylinder applications, this piston seal from Hercules Sealing Products is made for reliable performance in heavy equipment and industrial machinery.
Question by: Shane W on Apr 24, 2025, 2:43 PM
got a cylinder that calls out PSQ-88, is this the right piston seal or am i mixing parts up
Answer by: Customer Support on Apr 25, 2025, 9:36 PM
If your application references supplier part number PSQ-88, this is the direct-fit replacement. It is the Hercules Sealing Products piston seal with a 5-1/2 inch outer diameter, and it also crosses to MI-08751838 and MINO-00407X25584.
Question by: Lance C on Sep 14, 2025, 6:50 PM
Got a cylinder with a 5-1/2 inch bore that needs a new piston seal. This the right part to be lookin at?
Answer by: Customer Support on Sep 16, 2025, 5:56 PM
For a 5-1/2 inch outer diameter piston seal, yes, this is the one. The PSQ-88 is built specifically for that bore size and comes from Hercules Sealing Products, which has a solid reputation in fluid power applications. It also cross-references under part numbers MI-08751838 and MINO-00407X25584, so if you've got old paperwork or a parts list with either of those numbers, you're looking at the same seal.
