CAT 1779778 BASE AS for C18 Caterpillar Part - WSTPARTS
1779778 BASE AS for Caterpillar C18 — Genuine & OEM Replacement Part
WSTPARTS supplies genuine and high-quality OEM replacement BASE AS (Part # 1779778). Designed for CAT C18, C15, 330C, 336D, 325C, 325D, 330D, C13, C7, C9, 320D equipment.
Compatible Models
Key Features
- ✔ 100% compatible with CAT C18, C15, 330C, 336D, 325C, 325D, 330D, C13, C7, C9, 320D
- ✔ 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) | 1779778 |
| Product Name | BASE AS |
| Brand | CAT |
| Applicable Models | C18, C15, 330C, 336D, 325C, 325D, 330D, C13, C7, C9, 320D |
| Weight | 1.27 kg |
| Condition | New (Genuine / OEM Equivalent) |
| Warranty | 12 Months |
Where This Part Fits
Every row below is a real listing of 1779778 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 |
| 3126B | FUEL SYSTEM | 183-5876 | p.450 |
| 325C | FUEL SYSTEM | 183-5876 | p.151 |
| 330C | FUEL SYSTEM | 234-5136 | p.170 |
| 330D | FUEL SYSTEM | 237-8752 | p.117 |
| 336D | FUEL SYSTEM | 237-8752 | p.127 |
| C13 | FUEL SYSTEM | 243-3026 | p.510 |
| C15 | FUEL SYSTEM | 269-8415 | p.764 |
| C18 | FUEL SYSTEM | 212-9431 | p.430 |
System Notes — FUEL SYSTEM
The fuel system covers the injection pump, injectors, fuel transfer pump, filters and water separator, lines and the tank. It meters and atomises diesel at the precise moment and quantity the engine needs. Modern CAT engines run very tight injector tolerances, so the group is sensitive to water and dirt: a worn injector dribbles instead of atomising, causing rough idle, white smoke and diluted oil, while a clogged filter starves the pump under load. Parts here are replaced when the engine misfires, smokes, loses power under load, or when the water separator keeps tripping — always after the fuel quality itself has been ruled out.
FAQ
Is 1779778 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
