3278740 Hydraulic Gear Pump Seal Kit for CAT 312D

Product Description
Heavy-Duty 3278740 Hydraulic Gear Pump Repair Seal Kit for Caterpillar CAT 312D Excavator
Restore fast hydraulic response and eliminate fluid leakage in your pilot control system with Toparts' premium 3278740 gear pump seal kit. Precision-engineered for the hydraulic main/pilot gear pump assemblies fitted on Caterpillar CAT 312D hydraulic excavators, this overhaul service kit is built to maintain tight pressure containment under continuous high-speed rotation and severe hydraulic fluid temperatures.
The Toparts Engineering Difference: Built to Survive High-Speed Gear Rotation
Hydraulic gear pumps in excavators operate at high rotational RPMs under constant, severe pressure fluctuations. Inferior aftermarket oil seals quickly harden from friction heat, causing seal lip rollover, shaft scoring, and sudden pressure drop. At Toparts, we manufacture our 3278740 kits to address these exact operational vulnerabilities:
High-Velocity Fluorocarbon (FKM/Viton) & P6000 PU Formula: Molded from premium heat-resistant fluororubber and high-modulus P6000 polyurethane, ensuring continuous elastic sealing memory at operating temperatures reaching 120°C+ without lip carbonization.
Hydrodynamic Radial Lip Seal Design: The primary gear shaft seal features an integrated spring-loaded lip geometry that maintains consistent radial pressure against the rotating shaft, actively preventing hydraulic oil blow-by even during intense pressure spikes.
Anti-Contamination Auxiliary Wipers: Incorporates secondary dust sealing lips that aggressively block metal fines and abrasive debris from entering the internal gear chamber, protecting the pump casing from premature wear.
100% OEM Dimensional Accuracy: Machined to exact original tolerances for a seamless, drop-in replacement of CAT P/N 3278740, ensuring zero-leakage static seating across pump body plates and covers.
Technical Specifications:
Brand Compatibility: Caterpillar (CAT)
Excavator Model Application: CAT 312D / 312D L Series
Part Number (P/N): 3278740 / 327-8740
Target Component: Hydraulic Gear Pump / Pilot Charge Pump Group
Material Matrix: High-Performance FKM (Viton), Premium P6000 PU, Heavy-Duty NBR
Fluid Compatibility: Standard Hydraulic Mineral Oils, Synthetic Oils
Condition: 100% Brand New Industrial-Grade Aftermarket.

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There is €4.99 charge for delivery under €50 Orders. Additional charges will be imposed by our couriers for delivery to remote area, a surcharge may be levied to cover carriage to these areas.

Your product is covered by a 12 month Warranty or more if you opted for the extended warranty. Make sure you register your product.