Independent third-party component-level repair of legacy Sterling injection molding valves. Vickers / Eaton and Continental Hydraulics on standard machines, Bosch Rexroth on retrofitted units, and Moog servo bodies on accuracy-configured presses.
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
Spool & sleeve service
Spool wear, contamination scoring, and lap restoration on Vickers, Continental Hydraulics, and Rexroth bodies.
N220
Coil & solenoid work
Coil rebuild on legacy Vickers and Continental proportional bodies. Insulation breakdown is common after decades of service.
N230
Seal-pack replacement
Aged elastomeric seals harden and crack. Seal-pack replacement is standard scope on these rebuilds, using modern materials.
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 Vickers and Continental bodies on older Sterling machines.
N260
Repair scope
Bench-level component work on the valve hardware. PLC programming, machine parameter setup, and integration stay with the customer.
Worn spool lands and degraded clearances on aged Vickers, Continental Hydraulics, and Rexroth bodies.
Internal leakage
Aged seals and worn lap surfaces drive cross-port leakage past the spool.
Slow valve response
Contamination buildup and coil degradation slow valve switching after decades of service.
Coil & electronics
Proportional coils degrade from decades of thermal cycling, moisture, and electrical stress. Insulation breakdown common.
N500 Workflow
From part number to ship-back
Same four-step path through the shop whether the unit came off an original Sterling or one that's been retrofitted.
N510
Get in touch
Call or email with the part number, machine context, and a photo of the nameplate if it helps.
N520
Bench review
Tech opens the unit, inspects spool and coil, 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 Sterling valve repair
Application-specific questions. For brand-specific FAQs, see the dedicated brand page above.
What proportional valve brands come off Sterling machines?
Sterling injection molding machines run Vickers / Eaton proportional valves, Continental Hydraulics, Bosch Rexroth on larger or retrofit machines, and Moog servo valves on accuracy-configured units. All come off the bench for rebuild.
Can you repair valves from retrofitted Sterling machines?
Yes. Many Sterling machines have been upgraded with Bosch Rexroth 4WRPEH proportional valves replacing original Vickers or Continental units. Whichever body comes through the bench, the repair scope is similar.
Are OEM parts still available for Sterling?
OEM Sterling parts are increasingly difficult to source. The valves themselves are commercial Vickers, Continental, Rexroth, and Moog bodies that NC Servo can rebuild from inventory and donor stock.
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 Sterling machine programming or software configuration?
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 Sterling hydraulics.
Give us a call or send a part number with the machine context 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.
