Product Function & Specs:

4089258 is identified as a Cummins piston ring set used in internal engine repair and rebuilding applications. Piston rings support cylinder sealing, compression control, and engine oil control.

Public parts catalogues associate this reference with selected ISB, QSB, and 4B engine applications. Some listings identify a standard-size ring set, while the exact engine coverage and bore specification require confirmation using the engine serial number and cylinder measurements.

The ring set may include compression and oil-control rings, but the exact quantity and configuration should be confirmed against the supplier’s package information before installation.

Failure Symptoms:

• Excessive crankcase blow-by or reduced compression
• Increased engine oil consumption or exhaust smoke
• Loss of engine performance associated with worn piston rings

Quick Installation Notes:

• Verify the engine model, ESN, piston specification, and required ring size before installation.
• Measure cylinder bore condition and confirm the required clearance and ring end gap according to the service manual.
• Install the rings in the correct order and orientation, following the applicable Cummins repair procedure.

Maintenance Tips:

• Use the recommended engine oil and follow the prescribed oil-change intervals.
• Monitor oil consumption, crankcase pressure, smoke, and compression-related symptoms.
• Inspect cylinder walls, pistons, and ring grooves during engine overhaul work.

FAQ:

Q: What is Cummins 4089258?

A: 4089258 is a Cummins piston ring set used for selected diesel engine repair and rebuilding applications.

Q: Is 4089258 a standard-size ring set?

A: Several catalogues identify it as a standard-size ring set. Confirm the required bore size and cylinder condition before ordering.

Q: Which Cummins engines use this part?

A: Public listings associate the number with selected ISB, QSB, and 4B applications. Exact compatibility must be checked using the engine serial number and piston specification.

Q: Is this an OEM or aftermarket replacement?

A: This product is supplied as a new aftermarket replacement. It is not represented as a genuine Cummins factory part.

Q: What information is required before ordering?

A: Provide the engine model, ESN or CPL, piston and bore size, and the original ring-set number. These details help confirm the correct ring configuration.

Why Sourcing From WinsParts?

WinsParts supports part-number and engine-configuration checks before quotation, helping parts dealers and repair workshops reduce ordering errors. Worldwide export and shipping coordination is available.