Hydraulic servo & proportional valves
Servo valves, proportional valves, cartridge valves, and directional-control valves. Pilot stage, spool, coil, and connector rebuild on the bench, verified on Hagen-Busch and older-style hydraulic stands.
Industrial Equipment Repair
Independent third-party industrial equipment repair across hydraulic servo and proportional valves, servo drives and amplifiers, motion controllers, and industrial control panels. Component-level rebuild and bench verification at the NC Servo shop in Westland, Michigan. Working on this hardware across 30+ brands and nine industries since 1975.
What We Repair
Most of what comes through the shop falls into one of three buckets: hydraulic valves, electronic drives and amplifiers, or industrial control panels. Each category has its own test bench and documented procedures.
Servo valves, proportional valves, cartridge valves, and directional-control valves. Pilot stage, spool, coil, and connector rebuild on the bench, verified on Hagen-Busch and older-style hydraulic stands.
Servo drives, servo amplifiers, motion controllers, and proportional-valve driver cards. Component-level board repair: capacitors, transistors, relays, encoder feedback, and burned drive coils.
Gunner control display assemblies, weapon-station switch panels, industrial control modules, and remote amplifier units. Indicator lamps, toggles, protected-cover switches, internal wiring, and Mil-spec connectors.
In the Shop
Each unit is opened, inspected, and rebuilt at the component level. Failed parts come from past jobs when we have a match, or from cross-brand sourcing when we don't. Spool restoration, coil rewinding, and circuit-board work all happen in-house.
Hydraulic valves get verified on the Hagenbuch stand for current and CANbus-capable hardware, plus older-style legacy stands kept around for discontinued servo and proportional families. Drives and controllers get full-load functional testing on the electronics bench before ship. One-year workmanship warranty applies across both lanes.
Industries Served
The same families of servo valves, drives, and controllers move between very different machines. Click through to see the specific equipment and brands each industry runs.
Husky, Cincinnati Milacron, Van Dorn, Engel, Arburg, Battenfeld, and other injection-molding machine valves and drives.
MilitaryTank turret stabilization, weapon-positioning hydraulics, fire-control panels, and military ground support equipment.
AerospaceFlight simulator motion bases, control loading systems, hydraulic test stands, and aerospace ground equipment.
ConstructionExcavators, mobile cranes, concrete pumps and pavers, tunnel boring machines, and off-highway hydraulics.
SteelStamping, forging, extrusion press hydraulics and roll-force valves on steel mill process lines.
PaperStock-prep, headbox, basis-weight control, and paper-machine roll-position valves and drives.
LumberSawmill positioner valves, edger drives, and band-saw feed-rate hydraulics on lumber processing lines.
AutomationCNC machine tool drives, Fanuc / Allen-Bradley / Yaskawa servo amplifiers, industrial robot controllers, packaging-line drives.
Donor Parts & Cross-Brand Sourcing
Stock is hit or miss, but legacy hardware shows up often enough that we can pull from past jobs when we have a match. If a rebuilt match is on the shelf, customers can swap their failed unit for a discount. If we don't have a direct match, we'll suggest a comparable cross-brand option that drops in. Either way, give the shop a call with the part number and the situation.
Send a Part NumberBrands
Major OEMs the shop has worked on across hydraulic, electrohydraulic, and electronic equipment. Click through for the dedicated brand page.
Workflow
Same path through the shop whether the unit is a hydraulic valve, a servo drive, or a control panel. Lead time depends on the unit and donor parts availability.
Give us a call or send the part number with whatever info you have. Photo of the nameplate helps if you have it.
Tech opens the unit, inspects it, and runs it on the appropriate stand to confirm what failed.
The office calls back with what it'll cost and a rough turnaround. Nothing is started without your sign-off.
Failed components replaced, full bench verification, and the unit ships back with a one-year workmanship warranty.
FAQ
The questions maintenance teams ask most often. For brand-specific or industry-specific FAQs, see the relevant pages linked above.
Three main categories. First, hydraulic valves: servo valves, proportional valves, cartridge valves, and directional-control valves from Moog, Parker, Bosch Rexroth, Vickers, Atos, HR Textron, Abex, Atchley, and 20+ other brands. Second, electronic equipment: servo drives, servo amplifiers, motion controllers, and proportional-valve driver cards from Allen-Bradley, Fanuc, Indramat, Kollmorgen, Heldt & Rossi, and others. Third, industrial control panels and switch gear that come off military, aerospace, and industrial equipment. Bench-level component repair across all three lanes.
No. NC Servo Technology is an independent third-party repair facility. We are not affiliated with, authorized by, or endorsed by any equipment OEM. Brand names referenced on this site are the property of their respective owners and are used solely to identify the hardware we service.
No. Bench repair is the standard service: ship the unit to Westland, Michigan for rebuild and testing, then reinstall after return. This is what lets the shop run a 50+ year inventory of donor parts and dedicated test benches that wouldn't fit in a service truck.
Lead time varies job to job, partly because parts are often pulled from past jobs when we have a match. Give us a call with the part number and the situation and we'll give you a rough timeline.
If the unit isn't fixable, we'll let you know and either source a replacement from our shelf or suggest a comparable cross-brand option that drops in. No surprises.
Sometimes. 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 and we'll check the shelf.
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.
NC Servo Technology is at 38422 Webb Drive, Westland, Michigan 48185, in the Detroit metro area. Hardware ships in from across the country; the bench work happens here.
Resources
The two main repair lanes, the dedicated valve and drive hubs, and the technical explainers most customers reach for before sending in a unit.
Full directory of 20+ valve brands with dedicated pages for Moog, Parker, Bosch Rexroth, Vickers, Atos, and more.
Servo drive, amplifier, and motion controller repair across Allen-Bradley, Fanuc, Indramat, Kollmorgen, and more.
Heavy-industrial valve repair specifics: rebuild, exchange, donor parts, and cross-brand sourcing.
Combined valve and drive repair coverage across hydraulic systems.
Plain-English explainer on electrohydraulic servo valves: what's inside and why they fail.
Plain-language explanation of servo drives: what is inside, common architectures, and bench-level repair scope.
How proportional and servoproportional valves differ from true servo valves, and what gets done at the bench.
When component-level repair makes sense versus buying new or rebuilt. Common decision points for legacy hardware.
Contamination, hardened seals, blown coils, and the most common reasons servo valves fail in industrial service.
Bench testing workflow on the hydraulic stand: flow, pressure gain, null, leakage, and step response.
Give us a call or send the part number with the machine it came off. We'll check the shelf, suggest a rebuilt match if we have one, and walk through repair or cross-brand options if we don't.