Independent third-party component-level repair of servo and proportional valves on Van Dorn HT and Demag Ergotech, El-Exis SP, and Systec injection molding machines. Moog D660 / D661 / D662 servo valves and Bosch Rexroth 4WRPEH / 4WRSE / 4WRZ bodies come through the bench.
Each unit is opened, inspected, and rebuilt at the component level. Failed parts come from inventory or off donor units. Bench verification before ship.
N210
Pilot stage rebuild
Torque motor pilot stages, nozzle flapper, and pilot trim cleaned and aligned against documented procedures on Moog D660 / D661 / D662 valves.
N220
Spool & sleeve service
Spool wear, contamination scoring, and lap restoration on the servo and proportional valve bodies that come off Van Dorn / Demag machines.
N230
Coil & feedback work
Burned coil rebuild, feedback wire repair, and LVDT verification on closed-loop servo valve bodies.
N240
Bench testing
Hagenbusch and older-style hydraulic stands. Hysteresis, null shift, and step response data available for purchase.
N250
Donor parts service
Aftermarket and donor parts for legacy Van Dorn HT and Demag Ergotech bodies.
N260
Repair scope
Bench-level component work on the valve hardware. PLC programming, machine parameter setup, and integration stay with the customer.
Worn spool edges and contamination scoring on Moog D660 / D661 / D662 and Rexroth 4WRPEH bodies.
Internal leakage
Worn lap surfaces and degraded seals drive cross-port leakage past the spool.
Pilot & coil
Pilot null shift on Moog servo bodies, plus burned proportional coils on Rexroth valves.
Slow valve response
Sluggish valve dynamics from contamination and aged spool surfaces.
N500 Workflow
From part number to ship-back
Same four-step path through the shop whether the unit came off a Van Dorn HT toggle or a Demag El-Exis SP high-speed press.
N510
Get in touch
Call or email with the part number, machine model, 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 Van Dorn / Demag valve repair
Application-specific questions. For brand-specific FAQs, see the dedicated brand page above.
What servo valve brands come off Van Dorn and Demag machines?
Van Dorn HT and Demag Ergotech, El-Exis SP, and Systec machines typically run Moog D660 / D661 / D662 servo valves and Bosch Rexroth 4WRPEH / 4WRSE / 4WRZ proportional valves. All come off the bench for rebuild.
Can you repair valves on El-Exis SP high-speed machines?
Yes. El-Exis SP machines (150-750 metric tons) run Moog D660 / D661 / D662 servo valves. The valves come through the bench for full rebuild.
What's the difference between Ergotech, Systec, and El-Exis on the bench?
Ergotech and the successor Systec line run Rexroth 4WRPEH / 4WRSE / 4WRZ proportional valves; high-performance configurations use Moog D633 / D634 servo. El-Exis SP focuses on Moog accumulator-injection servo bodies. Repair scope is similar across all three.
How long does a repair usually take?
Lead time varies job to job, partly because parts are often pulled from donor boards. Give us a call with the part number and the situation.
Do you provide Van Dorn or Demag machine programming?
No. NC Servo handles bench-level component repair on the valve hardware only. PLC programming, machine parameter setup, and integration stay with the customer or OEM.
What if the valve is beyond economic repair?
If the valve is not fixable, we will let you know and help source a replacement.
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.
N700 More from NC Servo
Related repair coverage
Other injection-molding pages and the brand pages most-tied to Van Dorn / Demag hydraulics.
Give us a call or send a part number with the machine model and the symptom. We'll check the donor pool, suggest a rebuilt match if we have one, and walk through repair or cross-brand options if we don't.
