Agricultural Equipment Hydraulic Parts & Repair

RestoPower supplies parts for, and rebuilds, the hydraulic pumps, motors and steering units that keep tractors, combines, sprayers and ag implements working: Char-Lynn steering control units and orbital motors, Sundstrand and Sauer-Danfoss hydrostatic pumps and motors, Eaton heavy-duty hydrostatics, and Vickers and Parker pumps. Send us the code off the tag and we reply with price, availability and lead time on parts, or set up a free teardown evaluation and a firm, itemized quote for a rebuild.

Farm hydraulics fail at the worst time. A combine does not break down in February, it breaks down with the crop standing. So this page is laid out the way a breakdown goes: what you have, what failed, how to identify it, and the quickest honest way back into the field.

The short version: seal kits and parts for steering units, orbital motors and hydrostatic pumps and motors; a free teardown evaluation and a firm, itemized quote before any billable work; rebuilt to factory specification and function-tested; and, for work done in our shop, a 1-year repair warranty. In-stock parts ship within 24-72 hours and carry a 2-year warranty.

Our shop or our repair network. Your unit is repaired either in our shop in Lake Orion, Michigan, or through the RestoPower repair network, when a network shop closer to you can turn it around faster. We arrange getting the unit to the shop doing the work and tell you which shop before any work starts. The price, turnaround and warranty for a network job are confirmed on your quote.

Which hydraulic components on farm equipment do you supply and rebuild?

Most of the hydraulics on a tractor, combine or self-propelled sprayer fall into five families. The middle column is what the manufacturers' own catalogs say about where their product is used. It is not a fitment list.

Component Where the factory literature puts it Parts and service data
Char-Lynn / Eaton steering control units Eaton's steering catalog lists tractors, sprayers and combines among the applications for its steering control units, and lists compact utility tractors for its smaller Series 5 units. Char-Lynn steering units, steering unit parts and seal kits, 3, 4, 6 and 12 Series catalog
Char-Lynn / Eaton orbital motors Eaton lists crop sprayers, grape harvesters and specialty harvesting equipment for its VIS motors, seed drills and augers for its spool valve motors, and augers, spreaders and mixers for its disc valve motors. Char-Lynn orbital motors, Char-Lynn motor seal kits, orbital motor parts catalog
Sundstrand / Sauer-Danfoss hydrostatic pumps and motors Danfoss's Series 42 technical information lists utility tractors, windrowers, ag sprayers and specialized harvesters among the typical machines for its pump controls. Sundstrand / Sauer-Danfoss, Series 42 parts and seal kits, Series 18 parts
Eaton heavy-duty hydrostatic pumps and motors Eaton lists agricultural equipment first among the applications for its heavy-duty Series 1 and Series 2 pumps and its heavy-duty piston motors, with crop sprayers named for Series 2. Eaton heavy-duty hydrostatics, 33 / 39 / 46 parts, 54 / 64 parts
Vickers and Parker open-circuit pumps Eaton lists farm tractors and agricultural equipment for the Vickers PVE piston pump, and says the flex plate in Vickers VQ vane pumps is there for cold starts in harsh outdoor work. Vickers PVE catalog, PVE parts, Vickers vane pumps, Parker

None of the factory documents we used names a tractor or combine make and model with its pump, motor or steering unit, so we do not either. Your machine's parts book is the place for that. The tag on the unit itself is what we go by, and it is the fastest way to a correct quote.

Watch for OEM specials. Units built for a particular machine maker often carry a different shaft, port, valving or seal arrangement from the catalog unit with a similar number. Send the whole tag, every digit, and a photo. Rebuilding the unit you already have keeps every one of those details, and we never promise a 100% fit off a look-alike number.

What fails on tractor and combine hydraulics?

Most of what comes across our bench from farm equipment is one of a handful of failures, and a surprising amount of it started somewhere else in the system. Before you pull anything, match the symptom here and do the first check.

What you notice Usual cause Check first
Hard steering, slow steering or loss of assist Usually the pump, priority valve or relief feeding the steering unit, not the steering unit itself. Eaton's own repair manual says the steering unit is generally not the cause of most steering problems. Inlet pressure at the steering unit and the priority valve. See Char-Lynn steering unit troubleshooting.
Steering wheel oscillates or turns by itself after a reseal Eaton's troubleshooting chart puts this down to a steering unit timed wrong on reassembly, the classic rebuild mistake Hose routing first, then retime the gerotor to the drive per the manual for your series
Orbital motor on an auger, spreader or sprayer slows down or stalls under load Internal leakage from a worn gerotor or Geroler set, or a weak supply Supply flow and relief setting, then the motor. See orbital motor troubleshooting.
Orbital motor keeps blowing its shaft seal Back pressure or case pressure, very rarely a bad seal Return line and case drain routing, then fit the seal kit
Hydrostatic drive is weak, will not move, or fades as it warms up Low charge pressure, an open bypass valve, worn rotating groups Charge pressure with a gauge. See hydrostatic transmission troubleshooting.
Hydrostatic pump came apart Debris has already been through the motor on the same loop Plan to inspect the motor, flush the loop and change filters, not just replace the pump
Oil around the pump or motor shaft Case pressure pushing the lip seal, or a grooved shaft Case drain line and shaft condition. See shaft seal leaks.

If you only have a gauge and an afternoon, spend it on the system before the unit. A rebuilt pump or motor dropped into a circuit with the original fault still in it comes back on the same trailer.

How do I identify the pump, motor or steering unit?

Start with the tag. Every one of these units carries a model code or part number, and that code is what decides the seal kit, the parts and the rebuild.

Along with the code, tell us what the unit does on the machine (steering, ground drive, a header or auger drive, a fan), what it is doing wrong, and whether anything else in the system failed with it.

Rebuild, exchange or new: what makes sense in season?

On a shop floor in January the cheapest number wins. With a crop in the field, downtime is usually the bigger cost, and that changes the answer.

Option What you get When it is the right call
Seal kit, your own bench The correct seal kit for the unit's series and code The unit still steers, drives or turns properly and is only weeping, and you have the bench and the know-how.
Rebuild Full teardown, every seal and wear part replaced, worn surfaces machined or replaced, rebuilt to the original specification and function-tested The housing and shaft are serviceable and the wear is in the rotating group, gerotor set, valve plate, bearings or control.
Exchange Where we have a rebuilt unit on the shelf, you get it now and send your core back after The machine is down in season and every day costs more than the unit.
New unit A replacement unit, where one is still available The housing is cracked or the shaft and bore are past saving, or a new unit is the fastest way back to work.

Old units and OEM specials lean hard toward a rebuild, because the "replacement" often means new porting, a new shaft or a new mount. We will tell you if a rebuild is not worth it and quote a replacement instead. More on the money side is in what hydraulic pump repair actually costs.

What ag hydraulic parts can I buy from you?

These are the families we carry parts and seal kits for. Each link goes to a parts page or collection listing the parts for that series.

In-stock parts ship within 24-72 hours and carry a 2-year warranty. A part marked "request a quote" does not mean we do not have it or cannot get it. Ask, and we reply with price, availability and lead time.

How does an ag hydraulic repair job work?

  1. Tell us what you have. Send the tag code or a photo of it through request a quote, or call. We arrange getting the unit to the shop doing the work and send you shipping instructions.
  2. Free teardown and evaluation. The unit is taken apart, the wear parts measured, and the cause of the failure identified, at no charge.
  3. Firm, itemized quote. You approve the price before any billable work starts. If the unit is not worth rebuilding, we say so and quote a replacement.
  4. Rebuild and test. Rebuilt to factory specification and function-tested before it ships.
  5. Back to the machine. Work done in our shop carries a 1-year repair warranty. For a network job, the warranty is confirmed on your quote.

Replacing a unit rather than rebuilding it? Our core buyback program takes worn and damaged units for credit.

What should I do before the rebuilt unit goes back on?

Most early failures of rebuilt farm hydraulics are dirt. Change the filters, deal with whatever contaminated the system in the first place, and on a closed-loop hydrostatic drive flush the loop and the lines before the new or rebuilt pump goes in. Fill the case before start-up on units that need it. The guides that cover this properly:

Never drop a rebuilt pump into a loop that still has the old motor and the old oil in it. Debris from the failed unit will destroy the new one, and that failure is not covered by any warranty.

Frequently asked questions

Do you rebuild hydraulic pumps and motors for tractors and combines?

Yes. We rebuild Char-Lynn steering units and orbital motors, Sundstrand and Sauer-Danfoss hydrostatic pumps and motors, Eaton heavy-duty hydrostatics, and Vickers and Parker pumps, in our shop in Lake Orion, Michigan, or through the RestoPower repair network. The teardown evaluation is free and you get a firm, itemized quote before any billable work.

Can you tell me which pump or steering unit fits my tractor?

We work from the tag on the unit, not the machine model. Machine makers often use OEM special versions with their own shaft, porting or seal set, so the code on the unit is the reliable way to the right parts. Send the full code and a photo of the tag and we reply with price, availability and lead time.

Is the steering unit the problem when my tractor steers hard?

Usually not. Eaton's own repair manual says the steering unit is generally not the cause of most steering problems. Check the pump, priority valve and relief pressure at the steering unit inlet first. Binding, wheel kickback after a rebuild, or contamination damage are the times to open the steering unit.

My combine's hydrostatic pump failed. Does the motor need attention too?

Plan on it. The pump and motor share the same loop oil, so debris from a failed pump goes straight through the motor. Have the motor inspected, flush the loop and lines, and change the filters before the rebuilt pump goes in, or the damaged motor can destroy the new pump.

Do you offer exchange units during harvest?

Where we have a rebuilt unit on the shelf, yes. You get the rebuilt unit now and send your core back after, which is the least downtime of any option. Ask when you request your quote.

What warranty do I get on ag hydraulic parts and repairs?

In-stock parts carry a 2-year warranty and ship within 24-72 hours. Repair and rebuild work done in our shop carries a 1-year repair warranty. For a job handled through our repair network, the warranty is confirmed on your quote.

Do you sell seal kits for Char-Lynn steering units and Sundstrand pumps?

Yes. We carry seal kits and parts for Char-Lynn steering control units and orbital motors, Sundstrand and Sauer-Danfoss pumps and motors, and Eaton heavy-duty hydrostatics. If a kit shows request a quote, ask anyway: that does not mean we do not have it.

Machine down? Tell us what is on the tag.

Send the model code or a photo of the tag, what the unit does on the machine and what it is doing wrong. For parts we reply with price, availability and lead time. For a rebuild we arrange getting the unit to the shop doing the work, tear it down free and send a firm, itemized quote before any billable work.

Request a quote · (810) 882-1171 · Repair and rebuild service · Core buyback

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