CAT 4P7373 TUBE AS for C18 Caterpillar Part - WSTPARTS
4P7373 TUBE AS is a Fitting component engineered for Caterpillar C18, C15 and 3406C machines, built to match original factory specifications. It is categorized under Fitting. Every unit is fitment-verified before dispatch. Manual reference: 3406C: LUBRICATION SYSTEM, group 109-0078, page 449; C15: BASIC ENGINE, group 105-3386, page 404.
4P7373 TUBE AS for Caterpillar C18 — Genuine & OEM Replacement Part
WSTPARTS supplies genuine and high-quality OEM replacement TUBE AS (Part # 4P7373). Designed for CAT C18, C15, 3406C equipment.
Compatible Models
Key Features
- ✔ 100% compatible with CAT C18, C15, 3406C
- ✔ 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) | 4P7373 |
| Product Name | TUBE AS |
| Brand | CAT |
| Applicable Models | C18, C15, 3406C |
| Weight | 1.54 kg |
| Condition | New (Genuine / OEM Equivalent) |
| Warranty | 12 Months |
Where This Part Fits
Every row below is a real listing of 4P7373 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.449 |
| C15 | BASIC ENGINE | 105-3386 | p.404 |
| C18 | BASIC ENGINE | 241-2422 | p.175 |
| 3406C | LUBRICATION SYSTEM | 115-2353 | p.452 |
| C18 | BASIC ENGINE | 105-3386 | p.241 |
| C15 | BASIC ENGINE | 109-3285 | p.406 |
| C18 | BASIC ENGINE | 109-3285 | p.243 |
| C15 | BASIC ENGINE | 109-3289 | p.407 |
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 4P7373 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
