15789 O-ring Cat-DeWalt

The DeWalt 15789 O-Ring is a genuine OEM replacement sealing component used within the CAT pump assembly of compatible DeWalt gas pressure washers. DeWalt identifies this part in its service documentation as “ORING CAT.”

Product Specifications

Part Number: 15789
Part Type: O-Ring / Pump Seal
Manufacturer: DeWalt
Manufacturer Description: ORING CAT
Application: Pressure Washer CAT Pump Assembly
Quantity Used Per Applicable Pump Assembly: 1
Condition: Genuine OEM DeWalt Replacement Part

Tool Compatibility

DeWalt 15789 is documented in the pump assembly of compatible pressure washers including:

DeWalt DP2800 Type 1
DeWalt DP3100 Type 2
DeWalt DP3100IC Type 2
DeWalt DPD3000IC Type 1
DeWalt DPD3100IC – Applicable configurations

Verify the complete model and type number of your pressure washer against the applicable DeWalt pump parts diagram before ordering. Similar pressure washer models may use different pump assemblies and sealing components.

Part Function

The 15789 O-ring is an internal sealing component used within the CAT pump assembly. It creates a seal between mating components at its designated installation point and helps prevent fluid from passing through that connection during pump operation.

When to Replace the O-Ring

Replace the O-ring if it is cut, cracked, flattened, hardened, deteriorated, missing, or otherwise unable to form the required seal. O-rings should also be inspected whenever the corresponding pump components are disassembled for service.

A pressure washer leak or loss of pressure does not automatically indicate a failed 15789 O-ring. The pump contains multiple seals, O-rings, valves, plungers, fittings, and other components that should be inspected when diagnosing a pump problem.

Important Compatibility Information

Part number 15789 is specifically documented for certain CAT pump configurations used in DeWalt pressure washers. Do not select this O-ring based only on pressure washer PSI rating, physical appearance, or approximate size. Match the replacement to the exact pressure washer model, type, and pump parts diagram.