223-5944 Hydraulic Cylinder Seal Kit 2235944 for Caterpillar Loader Backhoe Bucket Excavator CAT 420D 430D 430E Repair
223-5944 Hydraulic Pump Seal Kit for Caterpillar® 336D Excavators – OEM-Approved Main Pump Sealing Solution
Product Overview
The 223-5944 Seal Kit is a Caterpillar®-authorized repair set designed for the main hydraulic pumps of Cat® 336D, 336D L, and 336D2 excavators. This kit restores factory sealing performance to prevent internal leakage, pressure loss, and contamination in high-demand hydraulic systems.
Technical Specifications
| Parameter | Specification |
|---|---|
| Compatible Models | Cat Loader Backhoe 420D 430D 430E, Excavators 336D, 336D L, 336D2 |
| Application | Main Hydraulic Pump Shaft Seals, Housing Gaskets, and Pressure Port Seals |
| Pressure Range | 0–35 MPa (5,076 PSI) – Matches Cat hydraulic pump operating standards |
| Temperature Tolerance | -25°C to +130°C (-13°F to +266°F) |
| Primary Seal Material | Fluorocarbon (FKM) – Resists thermal degradation and hydraulic oil swelling |
| Secondary Seals | Nitrile Rubber (NBR) O-Rings, PTFE Backup Rings |
| Certifications | ISO 3601 (Fluid Power Seals), Caterpillar 5P-1960 Compliance |
Kit Components & Functions
| Component | Function |
|---|---|
| 1. Shaft Seal (FKM) | Rotary lip seal prevents oil leakage along pump drive shafts. |
| 2. Port Seals (NBR) | Quad-ring seals for pressure line connections (SAE J518 port standards). |
| 3. Wear Plate Gasket | Precisely cut NBR gasket seals pump housing interface. |
| 4. Shaft O-Ring (HNBR) | Hydrogenated nitrile ring for high-pressure swivel joints. |
| 5. Backup Rings (PTFE) | Reinforces primary seals against extrusion under pressure spikes. |
| 6. Dust Seal (PU) | Polyurethane wiper blocks external debris from entering pump assembly. |
| 7. Bearing Housing Seal | Metal-cased FKM seal for bearing compartment isolation. |
Key Features & Benefits
✅ Exact OEM Replacement: Matches Cat part numbers 222-6701 and 434-7318.
✅ High-Pressure Stability: FKM seals maintain integrity in cyclic 35 MPa systems.
✅ Abrasion Resistance: PU dust seals extend service life in sandy/dusty job sites.
|✅ Oil Compatibility: Compatible with Cat HYDO Advanced 10, AW 46, and synthetic oils.
✅ Global Compliance: Meets EU Machinery Directive 2006/42/EC safety requirements.
