The Komatsu 707-99-67090 Arm Cylinder Seal Kit provides a complete hydraulic cylinder repair solution for Komatsu PC300-7 and PC300-8 series excavators. Precision-matched for a 160mm bore and 110mm rod diameter, this kit combines high-resistance TPU, PTFE, reinforced fabric resin, and nitrile (NBR) components for reliable high-pressure performance under heavy excavation loads.

Technical Specifications

Seal Kit Composition

Compatible Komatsu Models

• PC300-7 / PC300-8 / PC300LC-7 / PC300LC-8
• PC270-7 / PC270-7-AG
• PC340LC-7K
• PC400-7
• PC1250-8

FAQ

Q: Is this kit compatible with both Dash-7 and Dash-8 Komatsu PC300 models?
A: Yes, the 707-99-67090 is the standard arm cylinder seal kit for both the PC300-7 and PC300-8 series. Komatsu maintained the 160mm bore and 110mm rod specifications across these generations for this specific cylinder position.

Q: Why is the wiper seal metal-cased?
A: Komatsu arm cylinders are often exposed to heavy debris and abrasive materials. The metal casing on the 707-99-67090 wiper provides a rigid press-fit into the cylinder head, ensuring the seal remains securely in place even when scraping off hardened clay or mud.