4440-6221K Steering Cylinder Seal Kit for Doosan Daewoo Excavator Wheel Loader DL300 Series
4440-6221K Steering Cylinder Seal Kit Product Overview
4440-6221K Steering Cylinder Seal Kit – Equivalent for Doosan Daewoo DL300/MEGA 300/MEGA 300-V/MEGA 300-III Wheel Loaders & Excavators Repair. Precision-engineered replacement kit restores factory steering performance for Doosan Daewoo DL300-series equipment. Eliminates steering drift, hydraulic leaks, and sluggish response in wheel loaders and excavators. 44406221K Seal Kit Compatible with 5+ MEGA 300 variants and DL300 configurations.
Technical Specifications
| Compatible Models | DL300 • MEGA 300 • MEGA 300-III • MEGA 300-V |
| Cylinder Compatibility | 55mm/60mm/65mm bore sizes (and more standard or OEM) |
| Pressure Rating | 25 MPa working │ 32 MPa peak dynamic |
| Temperature Range | -40°C to +100°C (-40°F to +212°F) |
| Seal Materials | HNBR70 (Hydrogenated Nitrile) + Glass-Filled PTFE |
44406221K Seal Kit Contents
| Double-Action Piston Seal | Zero-leak 360° sealing @ 25 MPa |
| Lip-Type Rod Seal | <0.003mm blow-by control |
| Rotary Shaft Seal (FFKM) | Prevents swivel joint leaks |
| Lip Wiper (PU Seal) | Excludes 99.3% >20μm contaminants |
| Guide Rings (PTFE+Bronze) | Reduces stiction (CoF: 0.025) |
| HN70 O-Rings | Cold-flow resistant static seals |
Key Benefits
✅ Eliminates Steering Lag: Restores <0.5° wheel position hold per ISO 6011 drift test
✅ Arctic Performance: HNBR70 maintains elasticity at -40°C
✅ Abrasion Resistance: PTFE guide rings withstand 15,000+ loader pivot cycles
✅ Corrosion Protection: FFKM rotary seals resist salt/deicing fluids
Frequently Asked Questions (FAQ)
Q: Do you have any other excavator model repair seal kits ?
A: Yes. DJF As the professional excavator seal kits manufacturer, we produce all the excavators repair seal kits, standard sizes and also support customization. Please tell us the part number seal kit you want.
Q: I can’t find the model I want. Are all your seal repair kits here?
A: No. We have more than tens of thousands seal kits. Here only a small part of them is shown. We have stock of all the seal kits for construction machinery. Please contact us!
Contact Us
For more information or to request a quote, please contact us or email [email protected].
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