CAT 4J5573 SEAL for 345B Caterpillar Part - WSTPARTS
4J5573 SEAL is a Drivetrain component engineered for Caterpillar 345B, C15 and 365B machines, built to match original factory specifications. It is categorized under Drivetrain. Every unit is fitment-verified before dispatch, backed by factory-direct pricing and warranty coverage, and currently in stock for dispatch within 24 hours. Manual reference: 330C: HYDRAULIC SYSTEM, group 204-2702, page 472; 345B: LUBRICATION SYSTEM, group 143-4289, page 65.
4J5573 SEAL for Caterpillar 345B — Genuine CAT & Replacement Part
WSTPARTS supplies genuine CAT and OEM-equivalent direct-replacement SEAL (Part # 4J5573). Designed for CAT 345B, C15, 365B, 330C equipment.
Compatible Models
Key Features
- ✔ 100% compatible with CAT 345B, C15, 365B, 330C
- ✔ Meets Caterpillar original quality and performance standards
- ✔ Genuine CAT lines: New Genuine / Cat Reman / Cat Classic | OEM-equivalent direct replacements
- ✔ In stock, ready to ship
Specifications
| Part Number (MPN) | 4J5573 |
| Product Name | SEAL |
| Brand | CAT |
| Applicable Models | 345B, C15, 365B, 330C |
| Weight | 0.05 kg |
| Condition | New (Genuine CAT / OEM-equivalent direct replacement) |
| Warranty | 12 Months |
Where This Part Fits
Every row below is a real listing of 4J5573 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 |
| 330C | HYDRAULIC SYSTEM | 204-2702 | p.472 |
| 345B | LUBRICATION SYSTEM | 143-4289 | p.65 |
| 365B | HYDRAULIC SYSTEM | 145-7181 | p.555 |
| C15 | COOLING SYSTEM | 349-5034 | p.129 |
| 345B | HYDRAULIC SYSTEM | 121-1376 | p.448 |
System Notes — HYDRAULIC SYSTEM
The hydraulic system covers the main pump, control valves, cylinders, hydraulic tank, filters, hoses and all the fittings that connect them. It converts engine power into the pressure and flow that drive boom, bucket, steering and travel functions. Hydraulic parts fail mainly through contamination and heat: dirt that passes a worn breather scores pump components, aged hoses crack at the crimp, and O-rings harden and weep under pressure. A part in this group is normally replaced when a function drifts, a cylinder creeps, oil shows up under a machine that used to be dry, or the filter comes out loaded with metal.
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.
FAQ
Is 4J5573 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 345B.
Genuine CAT vs direct replacement — what is the difference?
Genuine CAT covers three factory lines: New Genuine, Cat Reman (core exchange with core charge) and Cat Classic (brand-new economy line). OEM-equivalent direct replacements are non-CAT parts; grade and warranty are confirmed in the quotation.
Stock, shipping and warranty?
In stock — ships within 24 hours. Every order is covered by a warranty per quotation.
📞 Get a Quote: Contact the WSTPARTS parts team | Email: cat@wstparts.com
