How We Repair Your Unit

Our process involves a teardown of your MOOG D644-308, mineral bath and ultrasonic cleaning, and reassembly with quality parts to restore operation.

Independent Repair Facility

Our technicians work on industrial components like the MOOG D644-308 daily. That hands-on repetition builds the kind of experience that speeds up diagnosis and reduces rework.

Specializing in MOOG D644-308 servo valve technology for over five decades

Frequently Asked Questions

Yes. Send us photos of the unit from multiple angles. Our team has serviced thousands of models and can often ID them visually.

We give you a straight assessment after inspection. If repair doesn’t make sense, we’ll let you know and discuss alternatives.

Part of our intake includes troubleshooting to determine the failure point. We report findings before proceeding.

We recommend sending pictures, especially if the model number is unclear or there is visible damage.

No cleaning required. Our repair process includes disassembly and cleaning of all components.

Disassembly and Rebuild Procedure

Every MOOG D644-308 gets a controlled teardown on our bench. We document condition, replace what’s needed, and reassemble to proper operating condition.

  • Final Performance Verification: After reassembly, each valve is bench-tested against published performance specifications.
  • Leak and Pressure Testing: The reassembled unit is leak-tested and pressure-tested to verify it meets published specs.
  • Cleaning: Units go through a mineral bath, with ultrasonic cleaning used for delicate internals.
  • Teardown: Every valve is disassembled for internal inspection.

Testing and Bench Verification

We carry out full diagnostics on every valve, including flow gain, leakage, pressure shift, and frequency testing. Our test facility supports performance logging and report generation. Our pre-shipment testing verifies consistent performance.

Technical Specifications

Every MOOG D644-308 we service is tested under real-world conditions. Our diagnostics verify performance against published specifications. Technical diagrams and Specification sheets are available for purchase upon request.

Parts and Inventory

With more than 17,000 valve units in inventory, we can often provide faster turnaround by sourcing parts in-house rather than waiting on OEM lead times.

Maintenance Tips

  • Schedule preventive maintenance intervals based on duty cycle, not just calendar time.
  • Conduct thorough visual inspections for wear or leaks during routine maintenance.
  • Monitor operating temperatures to identify potential issues before failure occurs.

Get an Expert Repair for Your MOOG D644-308

Request pricing, availability, and turnaround for your MOOG D644-308. NC Servo Tech provides independent repair with a 1-year warranty. Contact us to set up your repair.

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NC Servo Tech is an independent third-party repair facility. We are not affiliated with, endorsed by, sponsored by, or authorized by MOOG or any original equipment manufacturer (OEM), nor do we claim to be a MOOG service center. All brand names, trademarks, model numbers, and part numbers referenced on this page are the property of their respective owners and are used solely for identification and compatibility purposes.