Cummins NEW OEM 3101215 Rectangular Ring Seal 1.500 ID Viton Air Compressor 0810

Cummins Rectangular Ring Seal — Part Number 3101215

Brand: Cummins | Condition: New Old Stock (NOS)

Genuine Cummins original equipment rectangular ring seal, part number 3101215. Cummins catalogues it as SEAL, RECTANGULAR RING — a Viton sealing ring with a light blue PTFE coating, used in the air compressor circuit on the Cummins C, ISC, QSC, ISL and QSL engine families. From original dealer stock, never installed.

Condition Details

New Old Stock. The seal is new and unused, never fitted. As with all NOS stock, the original packaging may show shelf wear, dust, discoloration, handling marks, or age-related dirt, and bag printing may be faded. The part is sold as new; the packaging is sold as-is. The ring is true and unmarked, with the PTFE coating intact and the Viton supple — no cracking, hardening, flat-spotting, or set.

Specifications

• Part Number: 3101215
• Also written as: 310-1215
• Part Type: Seal, rectangular ring
• Inside Diameter: 1.500 in (38.1 mm)
• Cross Section: 0.100 in (2.54 mm)
• Thickness: 0.110 in (2.794 mm)
• Outside Diameter: approximately 1.700 in (43.2 mm)
• Material: Viton (FKM) 75 durometer, light blue PTFE / Teflon coated
• Section profile: rectangular, not round
• Sold: each (one ring per unit unless the listing photo shows otherwise)
• Manufacturer: Cummins, original equipment

One aftermarket supplier publishes different figures for this ring (1.7 × 1.65 × 0.05 in). The dimensions stated above come from the PAI-sourced specification data, which is internally consistent and gives the same 1.700 in outside diameter. If an exact dimension is critical to your application, message us and we will measure this ring and give you the figures from the part in hand.

Superseded & Cross Reference Part Numbers

• Cummins: 3101215, 310-1215
• PAI Industries: 121392
• Interstate-McBee: M-3101215

Cross references are provided to help identify the correct part. Please verify against your own parts manual or dealer lookup before ordering.

Features

• Genuine Cummins original equipment, correct rectangular section for the groove it seats in
• Viton (FKM), not nitrile. This is the single most important thing on this listing. Viton is specified where temperature and media would destroy a nitrile ring, and a nitrile substitute of identical dimensions will seat, will look right, and will fail
• Light blue PTFE coating. The Teflon coat reduces friction on installation and prevents the ring sticking to the mating face, so it comes out intact at the next service rather than tearing. A plain Viton ring is not the same part
• Rectangular section, not round. A rectangular ring presents a flat face to the sealing surface and behaves differently under compression than an O-ring of the same dimensions. An O-ring is not a substitute, whatever the size chart says
• Covers the C, ISC, QSC, ISL and QSL families — Cummins' mid-range 8.3 and 8.9 litre engines, used extensively in trucks, buses, motorhomes, fire apparatus, marine and industrial service
• Fully specified. Inside diameter, cross section, thickness and material are all stated above, so you can verify this is your ring before you buy
• A sub-$20 seal in an air compressor circuit. If it fails you lose air pressure, and on a commercial vehicle that is not an inconvenience

Application

Cummins engine families:

• C
• ISC
• QSC
• ISL
• QSL

Catalogued under air compressors and parts. One salvage inventory also lists this number against ISX, which we have not been able to confirm independently and are not claiming.

Cummins produced these families across many CPL variations, so please confirm 3101215 against your engine's parts manual, your CPL, or the old seal before ordering. If you are unsure, send us a message with your engine serial number and CPL and we will help you check it.

Why Choose Cummins?

Cummins has built diesel engines since 1919, and this ring is a compact illustration of why the factory part number matters more than the dimensions. Three separate decisions are built into it: the section is rectangular rather than round, because the groove and the sealing face were designed around a flat bearing surface; the compound is Viton rather than nitrile, because of what the seal lives next to; and the surface is PTFE coated, so it installs without rolling and releases without tearing. Any one of those substituted away gives you a ring that measures correctly and does not do the job. Cummins assigned a number to the combination — and that number is the only thing that reliably describes all three.

Returns

Returns accepted within 30 days through the eBay return request process. The part must be returned in the condition in which it was sent. Please confirm fitment against your engine's parts manual and CPL before ordering.

Thank you for looking at this listing. We are a small parts business and we work hard to describe every part accurately, including the condition of NOS packaging. If anything about this part is not what you expected when it arrives, please contact us first and give us the chance to make it right. We will always work with you.

If you have a part number you are hunting for and do not see it listed, send us a message — our inventory is considerably larger than what is posted at any given moment, and we are happy to check the shelves for you.

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