Need help identifying/repairing leaky Eaton hydraulic motor with missing ID tag

[KYErik]

This low speed motor runs the 6 inch unloading auger on a 6 ton fertilizer tender. The tender is probably at least 30 years old. The motor functions fine but is leaking heavily from around one of the bolt heads and also from the seam between the two halves of the case (in the center of the unit). It is not leaking around the shaft. It is 7" long and 3.25" in diameter.

I assume there are O- rings that seal the case- my issue is that I don't know what o-rings to order since the ID tag is missing. I am considering just replacing it with surplus center motor, but it would be nice to know the displacement so the replacement will be just as powerful but not overkill.

1. Anyone recognize the model or series? The bolt pattern seems to be unique.
2. Is this type of leak usually repairable by simply replacing the O -rings that seal the case or is it likely that the housing is warped/cracked and I would be better off buying a new replacement? I have never taken apart a hydraulic motor but I am comfortable rebuilding hydraulic cylinders and have rebuilt several gasoline engines.
3. Anyone have a guess as to the cubic inch displacement of this motor or experience with auger motors to know about what displacement I should order to replace it?

 

[CADplans]

A local hydraulics shop might pop in that O-ring for a few $$,,,
I would go there,,
they know O-ring sizes,, and materials,, to make sure the new part lasts.

 

[bigdeano]

That looks like an H series motor. All the displacements are the same diameter, just longer, so all would use the same O rings. I'd just clamp the shaft in a vice and take it apart one layer at a time. They're probably just standard buna-n O rings, available lots of places. Just measure and buy.

http://www.eaton.com/ecm/groups/public/@pub/@eaton/@hyd/documents/content/pct_1594418.pdf

 

[moship]

I can't comment on the series identification, but vote with the others concerning O-rings from a hydraulic supply house or any other place that may stock various sizes. I don't think you'll find any surprises or difficulties if you disassemble.

My experience... Recently dismantled a small hydraulic motor to due a leak in an attempt to rebuild it. Already had the rebuild kit on hand only to find the shaft was severely worn, so rebuilding was pointless. The O-rings and such were standard issue and nothing special would have be required to rebuild.

 

[wdchyd]

When doing a hyd motor reseal before proceeding we always note which port oil comes out when turning manually. These motors require timing between the shaft and geroler assembly. They can be timed wrong if not paying attention. We always use OEM seal kits as most of the section seals on this brand are thin square rings, plus there are new and old style shaft seals for this model too.
When it comes apart make careful notice if cover section is warped (might be the problem)

 

[KWentling]

When doing a hyd motor reseal before proceeding we always note which port oil comes out when turning manually. These motors require timing between the shaft and geroler assembly. They can be timed wrong if not paying attention. We always use OEM seal kits as most of the section seals on this brand are thin square rings, plus there are new and old style shaft seals for this model too.
When it comes apart make careful notice if cover section is warped (might be the problem)

This!!! It will not be an O-ring just any old hydraulic shop will have. As mentioned above, the displacement is determined by the length of the center section. A like replacement might be the best solution. Those motors are pretty cheap.

 

[KYErik]

Thanks guys. I will carefully pull it apart and look it over and then find a hydraulic shop to see if they can get the special o-rings and tell me how many cubic inches this motor is. It looks like I can get a new surplus center pump for around $150.

 

[bigdeano]

Even if they use square cross section O rings in that motor, a regular round O ring will seal just fine if it's squished a little when the parts are clamped together. Just measure the depth of the groove with a dial caliper. The O rings are a little over the nominal size, 1/16, 3/32, etc, so they squish and seal.

The cubic inches displacement are listed in the link I posted. Just depends on how long the center section is.

 

[KYErik]

Bigdeano,

Thanks- I didn't even think to try to use the measurements of the center section to look up the cubic inch displacement on the link you sent. Looks like it is a 23.8 cubic inch.

 

[wdchyd]

Even if they use square cross section O rings in that motor, a regular round O ring will seal just fine if it's squished a little when the parts are clamped together. Just measure the depth of the groove with a dial caliper. The O rings are a little over the nominal size, 1/16, 3/32, etc, so they squish and seal.

.

Not so......the cross section of the charlynn seals on the housing sections are smaller, squishing orings does not work and will only cause premature failure, more than likely the last guy to repair this hyd motor did just that.
Fix it once.....Fix it right