CAT 1090078 SEAL O RIN for C18 Caterpillar Part - WSTPARTS

The 1090078 SEAL O RIN is a genuine and high-quality OEM replacement part compatible with Caterpillar C18, C15 and 3412C equipment. It is categorized under Drivetrain. Every unit is fitment-verified before dispatch. Manual reference: 3406C: LUBRICATION SYSTEM, group 109-0078, page 448; 3406E: LUBRICATION SYSTEM, group 126-6886, page 205.

1090078 SEAL O RIN for Caterpillar C18 — Genuine & OEM Replacement Part

WSTPARTS supplies genuine and high-quality OEM replacement SEAL O RIN (Part # 1090078). Designed for CAT C18, C15, 3412C, 3406C, 3406E, C27, C32 equipment.

Compatible Models

Key Features

• ✔ 100% compatible with CAT C18, C15, 3412C, 3406C, 3406E, C27, C32
• ✔ Meets Caterpillar original quality and performance standards
• ✔ Genuine CAT parts with anti-counterfeit label | OEM alternatives with warranty
• ✔ Available for order, contact for lead time

Specifications

Part Number (MPN)	1090078
Product Name	SEAL O RIN
Brand	CAT
Applicable Models	C18, C15, 3412C, 3406C, 3406E, C27, C32
Weight	0.05 kg
Condition	New (Genuine / OEM Equivalent)
Warranty	12 Months

Where This Part Fits

Every row below is a real listing of 1090078 in the Caterpillar parts manual: the machine it is published under, the system it belongs to, the group number and the manual page. Use it to confirm the part against your own parts book before ordering.

Machine	System	Group No.	Manual Page
3406C	LUBRICATION SYSTEM	109-0078	p.448
3406E	LUBRICATION SYSTEM	126-6886	p.205
3412C	LUBRICATION SYSTEM	109-0078	p.226
C15	BASIC ENGINE	105-3386	p.404
C18	BASIC ENGINE	241-2422	p.175
C27	LUBRICATION SYSTEM	349-5622	p.106
C32	LUBRICATION SYSTEM	293-2874	p.118
3406E	LUBRICATION SYSTEM	109-0078	p.219

System Notes — LUBRICATION SYSTEM

The lubrication system covers the oil pump, oil cooler, oil filter base, relief valves, dipstick tube, pan and the galleries that distribute oil to every bearing in the engine. It is the system that keeps metal off metal. Failures tend to be either pressure loss — a worn pump, a stuck relief valve, a collapsed filter — or contamination, where sludge and debris circulate and score bearing surfaces. Oil pressure that reads low at idle, a filter that comes out heavy, or oil that turns dark far sooner than usual are the signals. Parts in this group are replaced on measured oil pressure and lab results rather than on interval alone.

System Notes — BASIC ENGINE

The basic engine group covers the core structure and internals: cylinder block, cylinder head, pistons, rings, liners, connecting rods, crankshaft, bearings, camshaft and the gasket sets that seal them. These parts determine compression, oil pressure and power output. They wear gradually — rings lose tension, bearings show copper, liners glaze — and the first signs are usually blow-by from the breather, rising oil consumption, or a knock that gets louder as the engine warms. Replacing a basic engine part is a planned overhaul decision rather than a roadside fix, so matching the exact part number and serial number range matters more here than anywhere else on the machine.

FAQ

Is 1090078 the right part for my machine?
Match the part number on your old part, or send us your equipment serial number — WSTPARTS verifies fitment free of charge for CAT C18.

Genuine vs OEM replacement — what is the difference?
Genuine CAT parts carry an anti-counterfeit label. OEM equivalents are built to the same specifications, bench-tested and supplied with full warranty at a better price.

Stock, shipping and warranty?
Lead time confirmed on request; we quote the fastest available option. Every order is covered by a 12-month warranty.

📞 Get a Quote: Contact the WSTPARTS parts team | Email: cat@wstparts.com