Independent third-party repair of servo and proportional valves on military ground support equipment: hydraulic test stands at depot maintenance facilities, hydraulic power units, tow tractors, aircraft jacks, and flight-line servicing rigs. Bench-level work on the same hydraulic stands the shop has run since 1975.
Ground support equipment runs hard on the flight line and at depot maintenance facilities. The four contexts below are the common application categories for this kind of valve work.
N110
Hydraulic test stands
Servo valves on depot-level test stands used to verify aircraft components, vehicle hydraulics, and weapon-system actuators. High-pressure systems with documented test procedures.
N120
Hydraulic power units
Mobile and stationary HPUs used to pressurize aircraft systems on the flight line. Servo and proportional valves on flow control and pressure regulation.
N130
Tow tractors & jacks
Aircraft tow tractors, hydraulic jacks, and lift platforms with proportional valves driving boom and lift functions in flight-line operations.
N140
Maintenance & servicing rigs
Aircraft servicing carts, fuel-rig hydraulics, weapons-handling equipment, and other maintenance rigs running commercial servo valves at depot and base level.
Each unit is opened, inspected, and rebuilt at the component level. Failed parts come from inventory or pulled off donor units. Bench verification before ship.
N210
Pilot stage rebuild
Torque motor, nozzle flapper, and jet pipe pilot stages cleaned, aligned, and trimmed against documented procedures.
N220
Spool & sleeve service
Spool wear, contamination scoring, and lap restoration on Moog, Parker, and Rexroth bodies.
Hagenbusch and older-style hydraulic stands for legacy GSE hardware. Performance data available for purchase.
N250
Donor parts service
Stock is hit or miss, but legacy hardware shows up often enough that we can pull from past jobs when we have a match. Ask about a specific part number.
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Repair scope
NC Servo handles bench-level component work. Depot certification and program-level sign-off stay with the customer or contractor.
Flight-line hydraulics see contamination, weather, and high duty cycles. The failures we see most often fall into the categories below. Recognize one? A part number is enough to start.
Nozzle flapper damage, torque motor coil burnout, jet alignment after a contamination event, and pilot null shift after long service in the field.
Spool and body
Spool wear, contamination scoring on lap surfaces, sticky spool action, and internal leakage past the spool on Moog, Parker, and Rexroth bodies.
Coil and feedback
Burned drive coils, feedback wire wear at the pilot, LVDT signal drift, and signal-path component failures.
Connector and electrical
Damaged connectors, cable strain at the entry point, and contamination on connector pins after years of flight-line and depot service.
N500 Workflow
From part number to ship-back
Same four-step path through the shop whether the unit is a depot test-stand servo or a flight-line tow-tractor proportional valve.
N510
Get in touch
Call or email with the part number, application context, and a photo of the nameplate if it helps.
N520
Bench review
Tech opens the unit, inspects pilot and spool, and runs it on the hydraulic stand to confirm what failed.
N530
Cost & approval
We call back with the cost and a rough turnaround. Nothing is started without your sign-off.
N540
Repair, test, ship
Failed components replaced from inventory or off donors, the valve verified under pressure, and shipped back.
N600 Common questions
Common questions about military GSE valve repair
Application-specific questions. For brand-specific FAQs, see the dedicated brand page in the brand list above.
What types of military GSE servo valves do you repair?
Servo valves and proportional valves on hydraulic test stands at depot maintenance facilities, hydraulic power units for aircraft servicing, tow tractors, jacks, and flight-line maintenance rigs. Moog, Parker, Rexroth, and Vickers commercial valves used across military ground support operations.
Are you affiliated with the DoD or any defense contractor?
No. NC Servo is an independent third-party repair facility. We are not affiliated with the U.S. Department of Defense, any military branch, or defense contractors. We service the commercial servo valves used in their ground support equipment.
Can you repair valves from depot test equipment?
Yes. Depot test stands run commercial servo valves, not classified hardware. We service the valve at the bench, the customer reinstalls it in the test rig and handles depot-level qualification on their end.
Do you handle ITAR, export control, or security clearances?
No. NC Servo does not hold an ITAR registration and does not handle export-controlled or classified material. Hardware-only repair. Customers and contractors handle all military qualification, certification, and program sign-off.
Do you offer field service at military bases?
Bench repair is the standard service path. You ship the valve to Westland, MI for rebuild and testing. On-site work is not our typical offering.
Do you provide programming or system integration?
No. We repair hardware components only at the bench level. PLC programming, parameter configuration, and system integration stay with the customer or OEM.
What is the warranty?
One year on parts and workmanship for repairs and rebuilt units. Standard exclusions apply for contamination, improper installation, and out-of-spec operation. Flushing and filtering the hydraulic system before reinstalling a repaired valve is recommended.
N700 More from NC Servo
Related repair coverage
Other military and aerospace pages plus the broader category hubs.
Give us a call or send the part number with the application context. We will check the donor pool, suggest a rebuilt match if we have one, and walk through repair or cross-brand options if we don't.
