Danfoss OMR 80 repair: when a seal kit is enough and when it isn’t
A small orbital motor starts to weep oil at the shaft, and someone says, “Just fit a seal kit.” Sometimes that’s right. Often the leak is a symptom of something worse inside, and the new seals fail again in a month. This guide shows how to tell the difference, which kit number to use and what a proper repair should include. Advance Hydraulic Works supplies hydraulic motors, pumps and valves to factories and plants across India and handles machine repair and maintenance, and this is how we’d go through it with you.
What’s inside the motor?
The Danfoss OMR 80 is a gerotor-type orbital motor with a displacement of 80.3 cm³, a 25 mm straight shaft and G1/2 side ports. The common version, 151-0411, is listed as design number 6. One listing describes it as a version without a drain port.
That last detail matters for repair. With no separate drain line, the shaft seal sits close to the motor’s low-pressure side, so return-line pressure and internal wear both show up as shaft leaks.
Danfoss OMR 80 seal kit: which one?
Danfoss publishes a seal kit table by series and shaft. For the OMR it shows kit 151-1277 for series 5 with 25 mm, 1 inch and tapered shafts, kit 151-1166 for the 32 and 35 mm tapered shafts, and kit 151-1286 for series 6 with the high-pressure shaft seal.
A distributor lists the contents of 151-1286 as one dust seal, one shaft seal, three 75.9 mm O-rings, three 90 mm O-rings and seven washers. A US catalogue lists it at $39.90. That’s a small fraction of a motor’s price.
So for a design 6 Danfoss OMR 80 seal kit, 151-1286 is the likely match. But confirm the design or series on your nameplate, because a series 5 motor takes a different kit. A seal kit under number 11188319 is also listed for the newer White versions, which are a different generation.
What a seal kit can and can’t fix
A seal kit covers the soft parts: shaft seal, dust seal, O-rings and washers. It fixes:
- A leak at the shaft where the motor still turns at the right speed.
- Weeping at the flange joints.
It won’t fix:
- Slow output under load.
- Hot oil from internal leakage.
- A scored shaft or worn bearings.
- A worn gerotor set or valve parts.
If the motor is weak as well as leaking, the seals aren’t the root cause.
Danfoss OMR 80 repair service: what a proper job includes
Whoever does the work, a good Danfoss OMR 80 repair service should:
- Identify the motor’s design and series from the nameplate.
- Strip it and inspect the gerotor set, valve parts, drive shaft and bearings.
- Measure wear and tell you plainly which parts are worn.
- Replace worn parts and every seal, using the right kit.
- Rebuild in clean conditions.
- Test speed, leakage and pressure before it leaves.
- Give you the test results.
Ask any shop, including Advance Hydraulic Works, to confirm these steps before you accept a quote.
The method: inspect, test, decide
Inspect. Look for the source of the leak and check the shaft for scoring. Check the return line for back pressure.
Test. Run the motor at a known flow and measure its speed.
Decide. Good speed means a seal kit may be enough. Low speed means internal wear.
A worked example
At 40 litres per minute, a healthy motor of 80.3 cm³ turns at about 40,000 ÷ 80.3, roughly 498 rpm. Suppose yours turns at 430 rpm under the same flow. At 430 rpm it passes 430 × 80.3 = 34,529 cc a minute, about 34.5 litres per minute, so around 5.5 litres per minute leaks internally. At 120 bar, that’s about 120 × 5.5 ÷ 600, around 1.1 kW turning into heat. A new seal kit wouldn’t touch that. If the motor had turned at 495 rpm with only a shaft leak, the kit would be the right answer. This is illustrative arithmetic, and acceptable limits depend on the data for your exact motor.
Implementation steps
- Photograph the motor, its nameplate and the leak before removal.
- Write down the full part number and the design or series.
- Check return-line pressure and rule out a blocked return.
- Test speed at a known flow if you can.
- Send photos and readings to Advance Hydraulic Works and ask for an assessment.
- If a seal kit is enough, ask the seller to match it to your series in writing.
- If not, ask for a repair quote with parts, testing and turnaround.
- After repair, refit the motor, run it unloaded first and watch for leaks and heat.
The usual mistakes are fitting the wrong kit for the series, fitting a kit onto a worn motor and ignoring return-line pressure.
FAQs
Which Danfoss OMR 80 seal kit do I need?
For a design 6 motor, such as the 151-0411, the kit is generally 151-1286. A series 5 motor takes a different kit, so check the nameplate.
What is included in a Danfoss OMR 80 seal kit?
Typically a dust seal, a shaft seal, O-rings and washers. Check the kit’s parts list against your series.
When is a seal kit not enough for Danfoss OMR 80 repair?
When the motor is slow, hot or weak as well as leaking. That points to internal wear that seals can’t fix.
What does a Danfoss OMR 80 repair service include?
Identifying the motor, stripping and inspecting it, replacing worn parts and seals, rebuilding it cleanly and testing it. Ask for the test results.
Can Advance Hydraulic Works help with a Danfoss OMR 80 seal kit or repair?
Send the photos, nameplate and symptoms to Advance Hydraulic Works and ask about the right kit or a repair assessment before you commit.
Your next step
Photograph the motor, note the symptoms and send everything to Advance Hydraulic Works. You’ll know whether it’s a seal kit or a bigger job before you spend anything.
