Servo and proportional
Servo valves and proportional directional valves used for injection speed, clamp pressure, and back-pressure control on the molding cycle.
NC Servo Technology - Westland, Michigan
734-326-6666
Independent Repair Shop. Not Van Dorn.
Third-Party Repair of Van Dorn Hydraulic Valves
Independent third-party repair of hydraulic valves off Van Dorn injection molding machines: servo valves, proportional valves, directional, pressure, and flow control bodies. Whether the valve wears a Van Dorn nameplate or a Bosch / Vickers OEM-integrated label, the bench work is the same. Backed by a 19,000+ unit in-house inventory we pull aftermarket and donor parts from. NC Servo is not affiliated with Van Dorn. Working on this kind of hardware since 1975.
Injection-molding focus
Hydraulic valves off Van Dorn molding machines, including OEM-integrated valves on the platen.
Cross-brand on the same machine
Van Dorn-labeled, Bosch, Vickers, and other OEM valves all come through the same bench.
One-year warranty
Standard on parts and workmanship for Van Dorn repairs and rebuilt units.
Brand Reality
Van Dorn is a machine builder; the valve might not be Van Dorn
Van Dorn was an American injection molding machine builder out of Cleveland, Ohio. The brand still shows up on machines in plants across North America. The hydraulic valves on a Van Dorn machine were sometimes Van Dorn-branded and sometimes OEM-integrated parts from third-party valve makers. The bench work is the same regardless of whose label is on the side.
- Van Dorn-labeled servo, proportional, and directional valves on the original machine.
- Bosch, Vickers, or other OEM valves integrated at the factory.
- Aftermarket replacements installed during prior repairs over the machine's life.
- Mixed-label hardware on the same molding line is normal and not a problem on the bench.
Service Coverage
What NC Servo does with a Van Dorn valve
Whatever valve came off your Van Dorn machine, the shop opens it, finds what failed, and rebuilds it at the component level using parts from inventory or pulled off donor units when needed.
Pressure and flow
Pressure control and flow control valves on the hydraulic power unit, plus directional bodies on the manifold side.
OEM-integrated valves
Bosch, Vickers, and other valve brands that came in as part of the original Van Dorn build. Same bench, same rebuild.
Van Dorn Coverage
Valves through the door from Van Dorn machines
We are a small repair shop, not a Van Dorn distributor. The categories below are simply what comes through often enough to be familiar. If the part number on your unit is not in this list, send it anyway. We work on what we can.
Van Dorn-labeled bodies
Servo, proportional, and directional valves carrying the Van Dorn brand on the nameplate. Discontinued and current.
OEM-integrated valves
Bosch, Vickers, and other third-party valves that shipped as part of the original Van Dorn build. We work on these too.
Aftermarket replacements
Replacement valves installed over the machine's service life. Cross-brand alternatives sourced and rebuilt.
Common Faults
What usually shows up on a Van Dorn valve
A description of the symptom and the molding-cycle stage where it happens helps the diagnosis. The categories below cover the kinds of trouble that come in across Van Dorn molding-machine valves.
| Pilot stage and feedback | Pilot-pressure null shift, contamination in the pilot path, feedback wire wear, or signal drift on closed-loop servo valves. |
|---|---|
| Spool and body | Spool wear, contamination scoring, sticky spool action, internal leakage past the spool, or seal failure on injection and clamp circuits. |
| Coils and driver electronics | Burned proportional coils, failed onboard driver cards, blown output stages, or open windings on the pilot stage. |
| Molding-cycle wear | Heat damage from running near process temperatures, contamination evidence from old hydraulic fluid, and seal hardening from years of cyclic operation. |
Repair Path
From part number to ship-back
Most Van Dorn jobs follow the same four steps. Lead time varies because some repairs need parts pulled off a donor unit, so we only commit to timing once a tech has the valve on the bench.
Get in touch
Phone or email with the part number, the Van Dorn machine model, and a quick note on which part of the molding cycle the valve sits in.
Bench review
Once the unit arrives, a tech opens it, inspects spool and pilot, and runs it on the hydraulic stand to confirm what failed.
Cost & approval
We call back with the cost and a rough turnaround. Nothing happens without your sign-off.
Repair, test, ship
Failed components are replaced from inventory or off donors, the valve is verified under pressure, and the unit ships back.
Bench Verification
Each Van Dorn valve gets pressurized before ship
Repaired Van Dorn valves are checked on the hydraulic test stands before they leave. Flow, pressure gain, response, null, and leakage are verified against documented procedures for the family.
- Flow characterization across the operating range for the valve.
- Pressure gain and step-response measurement against documented procedures.
- Internal and external leakage checked after seal and spool work.
- Older stands kept on hand for legacy Van Dorn-era hardware.
Inventory & Parts Pool
A 19,000+ unit pool with Van Dorn-machine valves in it
NC Servo's in-house inventory holds over 19,000 valves and drives accumulated since 1975, including valves that came off Van Dorn molding machines over the years. That pool is where the shop pulls aftermarket parts and donor components for Van Dorn-machine hydraulic systems.
- Aftermarket and donor parts for Van Dorn-labeled valves and OEM-integrated bodies from Bosch, Vickers, and others.
- If we have a rebuilt match for your part number, trade in your old valve for a discount on the rebuilt.
- No match on the shelf? We can suggest a comparable cross-brand option, or repair yours.
- Rebuilt valves carry the same 1-year warranty as a fresh repair.
Repair Scope
Where the line is on a Van Dorn repair
NC Servo works on the valve hardware itself: the body, spool, pilot stage, coils, and any onboard driver-card components. Hydraulic system design, machine-cycle setup, and getting the valve back on the molding machine stay with your team or your installer.
- Internal valve work: spool service, seal replacement, pilot stage cleaning, coil rebuild.
- Onboard driver-card service on units with integrated electronics.
- Molding-machine cycle setup and HPU tuning remain on your side.
- Putting the valve back on the machine follows your normal startup process.
More on Van Dorn Repair
Related pages and brands
Van Dorn machines and the valves on them tie directly to the broader injection-molding service line. The pages below cover the relevant industry hub and the cross-brand work.
Valve repair hub
The full range of servo and proportional valve repair NC Servo handles, across the brands that come through the shop.
Injection molding hub
How valve repair fits into broader injection-molding-machine service, including Van Dorn, Cincinnati, and others.
Vickers servo valves
Common OEM-integrated brand on Van Dorn machines. Useful when your nameplate reads Vickers and not Van Dorn.
Bosch hydraulic valves
Another common OEM-integrated brand on Van Dorn machines. Useful when the label says Bosch.
Van Dorn molding machine valve down?
Give us a call with the part number off the valve, the Van Dorn machine model, and a quick description of where in the cycle the issue shows. We will check the shelf, and if we have a rebuilt match you can swap your old one for a discount. If we do not, we can suggest a comparable valve or repair the one you have.
FAQ
Common questions about Van Dorn repair
A few things customers ask before sending a unit in. Anything not covered, give us a call at 734-326-6666.
Is NC Servo affiliated with Van Dorn?
No. NC Servo Technology is an independent, third-party repair facility and is not affiliated with, authorized by, or endorsed by Van Dorn, Sumitomo (SHI) Demag, or any related entities. All Van Dorn trademarks are the property of their respective owners.
Is Van Dorn a valve brand or a machine brand?
Van Dorn is best known as an American injection molding machine builder, originally based in Cleveland, Ohio. The valves on a Van Dorn machine are sometimes Van Dorn-branded and sometimes OEM-integrated parts from Bosch, Vickers, or other valve makers. We work on whichever valve came off your machine, regardless of whose label is on it.
Which Van Dorn valves do you cover?
Servo valves, proportional directional valves, pressure valves, and flow control valves used on Van Dorn injection molding machines. Send the part number off the nameplate and we will tell you what we have, regardless of whether the label says Van Dorn or another OEM brand.
Can NC Servo recover programs from a Van Dorn valve?
Most failures are hardware, and the unit comes back working with its program intact. Corrupted programs are rare; if one is already corrupted before the unit reaches us, that's the one thing we can't recover.
How long does a Van Dorn repair take?
It varies. NC Servo is a small independent shop, and lead time depends on the valve, what is wrong with it, and whether parts have to come off a donor unit. Give us a call once the unit ships in, and we can give a current estimate after a tech has looked at it.
What if the Van Dorn valve is beyond economic repair?
If the valve is not fixable, we will let you know and help source a replacement: a rebuilt match if we have one on the shelf, or a comparable cross-brand alternative.
What is the warranty on a Van Dorn repair?
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.