% O1975 · NC Servo Technology Fisher Servo Valve Repair Independent · third-party repair

Fisher Servo Valve Repair

Independent third-party component-level repair of legacy Fisher injection molding machine valves. Continental Hydraulics, Vickers / Eaton, and retrofitted Bosch Rexroth proportional bodies on 100 to 500 ton machines.

Vickers proportional valve used in Fisher injection molding machines
Fig. 01 — Vickers proportional valve used in Fisher injection molding machines
Vickers
KBDG, KFDG, KDG series
Eaton
Industrial proportional
4 platforms
Seen at the bench
1 year
Parts & workmanship

N100 Where these valves sit

Four Fisher machine contexts

Fisher machines were American-built injection molding equipment. Many remain in active use. Below are the four common contexts seen at the bench.

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100-250 ton machines

Smaller-tonnage Fisher machines for consumer products, medical components, and accuracy parts. Vickers / Eaton and Continental Hydraulics proportional valves.

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300-500 ton machines

Larger machines for automotive parts and industrial components. Same Continental Hydraulics and Vickers valve platforms with higher flow ratings.

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Retrofitted machines

Many Fisher machines have been modernized with updated controls. Retrofits commonly use Bosch Rexroth proportional valves replacing original Continental / Vickers bodies.

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Auxiliary & legacy units

Continental Hydraulics proportional valves come through the bench from auxiliary positions on Fisher machines across all tonnages.

N200 What NC Servo does

Component-level repair on Fisher valves

Each unit is opened, inspected, and rebuilt at the component level. Failed parts come from inventory or off donor units. Bench verification before ship.

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Spool & sleeve service

Spool wear, contamination scoring, and lap restoration on Continental Hydraulics, Vickers / Eaton, and Rexroth bodies.

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Coil & solenoid work

Coil rebuild on legacy Vickers and Continental proportional bodies. Insulation breakdown is common after decades of service.

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Seal & o-ring service

Aged elastomeric seals harden and crack. Full seal-pack replacement during every rebuild.

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Bench testing

Hagenbusch and older-style hydraulic stands. Hysteresis, null shift, and step response data available for purchase.

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Donor parts service

Aftermarket and donor parts for legacy Continental Hydraulics and Vickers bodies. Many are no longer in OEM stock.

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Repair scope

Bench-level component work on the valve hardware. PLC programming, machine parameter setup, and integration stay with the customer.

N400 Common faults

What usually shows up on Fisher valves

Fisher machines are decades old. Age-related valve degradation is the primary concern, compounded by contamination accumulated over years of operation. Recognize one? A part number is enough to start.

Fault log — typical intake
Coil insulation breakdownSolenoid coils on Vickers and Continental valves degrade after decades of thermal cycling and electrical stress. Drives intermittent control loss.
Seal degradationElastomeric seals harden and crack with age. Drives internal leakage and unpredictable valve behavior.
Spool wearWorn spool lands and degraded clearances on aged Vickers and Continental bodies. Common on high-cycle machines.
Contamination buildupYears of accumulated contamination in older hydraulic systems jam spool edges and reduce valve response.

N500 Workflow

From part number to ship-back

Same four-step path through the shop whether the unit came off an original Fisher machine or one that's been retrofitted.

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Get in touch

Call or email with the part number, machine context, and a photo of the nameplate if it helps.

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Bench review

Tech opens the unit, inspects spool and coil, and runs it on the hydraulic stand to confirm what failed.

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Cost & approval

We call back with the cost and a rough turnaround. Nothing is started without your sign-off.

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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 Fisher valve repair

Application-specific questions. For brand-specific FAQs, see the dedicated brand page above.

What proportional valve brands are used in Fisher machines?
Fisher injection molding machines (American-built equipment from that era) most commonly used Continental Hydraulics proportional valves and Vickers / Eaton proportional valves. Retrofitted machines may also feature Bosch Rexroth proportional valves.
Can you repair valves from retrofitted Fisher machines?
Yes. Many Fisher machines have been modernized over the years with updated controls and replacement valves. Whether the valve on the bench is original Continental Hydraulics, Vickers, or a Rexroth retrofit, the repair scope is the same.
Are OEM replacement parts still available for Fisher machines?
OEM Fisher replacement parts are increasingly difficult to source. The valves themselves are commercial Continental Hydraulics, Vickers / Eaton, and Rexroth 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 Fisher 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.

N990 Get a quote

Fisher valve down? Send a part number

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.

NC Servo Technology is an independent, third-party repair facility specializing in servo valve, proportional valve, and electronic control repair. We service hydraulic and electronic components used in Fisher injection molding machines. We are not affiliated with, authorized by, or endorsed by Fisher, Continental Hydraulics, Vickers / Eaton, Bosch Rexroth, or any related entities, and we do not claim to repair injection molding machines themselves. All brand names, model numbers, and trademarks referenced on this page are the property of their respective owners and are used solely for the purpose of identifying compatible equipment serviced by NC Servo Technology. 38422 Webb Dr, Westland, MI 48185. 734-326-6666.