Hydraulic motor repair is the right call when the housing is sound and the wear sits on internal parts such as bearings and the rotating group. Hydraulic motor replacement is the right call when the housing is cracked or the failure has pushed metal debris through the rest of the circuit. A test under load confirms the decision.
Motors rarely stop without warning. A winch pulls slower at full load, or a drive motor gets louder once the oil warms up. The machine keeps working, so the motor stays in service until it can’t hold the load anymore. By the time it reaches our bench, the question is simple: is the housing worth saving?
What Does Hydraulic Motor Repair Include?
Hydraulic motor repair is the teardown, inspection, parts replacement and testing of a motor so it performs to its original specification. We disassemble the motor, measure every wear surface against OEM tolerances, replace worn parts from our parts inventory and run the rebuilt unit on our test stands before it ships.
We repair these motor types:
- External gear motors
- Internal gear motors, both direct drive gerotor and orbiting gerotor designs
- Roller vane gerotor motors
- Vane motors
Brands include Bosch Rexroth, Parker Hannifin, Linde, Sauer Danfoss, Denison, Eaton, Oilgear, Sundstrand and Rineer. We keep a large stock of motor parts in our warehouse, which is what lets us offer 24-hour turnaround on repairs and, in some cases, same-day service.
Which Symptoms Point to a Failing Motor?
Hydraulic motor troubleshooting starts with the symptom, then rules out the rest of the circuit. These are the signs we ask customers about first:
- Torque loss under load. The motor slows or stalls at loads it used to pull. Internal leakage across worn surfaces is the usual cause.
- Higher case drain flow. On piston motors, more oil leaving the case drain means more oil slipping past internal clearances. Measuring case drain flow against the maker’s figure is one of the fastest checks you can run in the field.
- Noise changes. Whining often points to air in the oil or cavitation. Knocking or grinding points to bearing or rotating group damage.
- Oil at the shaft seal. A worn seal leaks, and so does a good seal facing too much case pressure from a restricted case drain line.
- Heat. A motor running hotter than the rest of the circuit is losing energy to internal leakage or friction.
Check the circuit before you pull the motor. A weak pump, a relief valve set low or a kinked case drain hose can make a healthy motor look worn. Our guide on how to identify when your hydraulic equipment needs repair covers those checks in order.
When Is Repair the Better Choice?
Repair is the better choice when the damage is contained inside the motor. We recommend repair when:
- The housing has no cracks and the bores measure within tolerance.
- The output shaft and splines are serviceable.
- The wear sits on seals, bearings or rotating group parts we can replace or restore to spec.
- The contamination was caught before it reached the pump and valves.
If those conditions hold, a repair costs less than a new motor and keeps the original unit on the machine. That matters most when a new motor has a long lead time.
When Does Hydraulic Motor Replacement Make More Sense?
Hydraulic motor replacement makes more sense once the damage has gone past the motor’s internal parts. We recommend replacement when:
- The housing is cracked or distorted.
- The failure has sent metal debris or burnt oil into the rest of the circuit.
- The repair quote is close to the price of a rebuilt unit.
- The machine can’t sit idle for a full teardown and rebuild.
Replacement can still mean a rebuilt unit. Our core exchange program swaps your failed unit for one we have already rebuilt and tested, so the machine goes back to work while we rebuild your core. If debris has already spread, read our article on diagnosing common hydraulic system failures before you install anything, because a new motor in a dirty circuit wears out fast.
Hydraulic Motor Repair or Replacement: A Side-by-Side View
|
Factor |
Repair |
Replacement |
|
Housing |
Intact, bores in tolerance |
Cracked or distorted |
|
Damage |
Seals, bearings, rotating group |
Debris spread through the circuit |
|
Cost |
Parts and labor, usually lower |
Full unit, lower with a rebuilt exchange |
|
Downtime |
24 hours when parts are in stock |
Shortest with an exchange unit on hand |
What Is the Difference Between a Repair and a Hydraulic Motor Rebuild?
A hydraulic motor rebuild is the complete version of a repair: every part inspected, every worn part replaced and the motor tested before it ships. A repair can be narrower, such as a shaft seal replacement on a motor that is otherwise in good shape. We quote both, and the teardown report shows which one your motor needs.
How Do We Confirm the Motor Is Fixed?
We run every rebuilt motor on one of our two diesel-powered test stands, rated at 318 hp and 900 hp, with reversible drives from 0 to 2300 rpm. The stands test units up to 6000 psi and take mounting plates for motors from 10 to 1000 cc/rev. Each motor is checked for efficiency, control function, relief valve settings and leaks under pressure, with a final leak check in a bubble tank.
Motors fitted with counterbalance or cross-port relief valves get those valves tested on the motor, up to 200 cc/rev. The full list is on our hydraulic testing capabilities page.
What Speeds Up a Quote?
A complete request gets a faster answer from our hydraulic motor repair services team. Send the motor’s brand, model and part or serial number, the machine it runs on and what it does when the problem shows up. Our guide on what to include when requesting a hydraulic repair quote lists the rest.
Get a Teardown Before You Buy a New Motor
A new motor is an expensive way to find out the old one was repairable. The teardown shows what failed and what each option costs, so you can compare real numbers before you spend.
Contact our team with your motor’s details. We’ll quote the hydraulic motor repair, or a rebuilt exchange unit if downtime is the higher cost.
Frequently Asked Questions
How Do I Know if My Hydraulic Motor Can Be Repaired?
A hydraulic motor can usually be repaired when the housing has no cracks and the shaft is serviceable. A teardown and inspection confirm it, since the outside of the motor shows very little of what is happening inside.
What Is the Difference Between Hydraulic Motor Repair and a Rebuild?
Hydraulic motor repair can fix a single failed part, such as a shaft seal. A hydraulic motor rebuild covers the whole motor: full disassembly, inspection against tolerance, replacement of every worn part and a test under load.
How Long Does Hydraulic Motor Repair Take?
Our parts inventory lets us offer 24-hour turnaround on repairs and same-day service in some cases. Motors that need parts we don’t stock take longer, and we give you the timeline with the quote.
Is a Rebuilt Hydraulic Motor as Reliable as a New One?
A rebuilt motor that passes a load test performs to the original specification. The test data is the proof, so ask any repair shop for it before the motor ships.
When Is Hydraulic Motor Replacement the Better Option?
Hydraulic motor replacement is the better option when the housing is cracked, when debris has spread through the circuit or when the machine can’t wait for a rebuild. A rebuilt exchange unit is often the fastest way back to work.