My '49 8N, "Bessie", has a Dearborn front-end loader. In years past I have made repairs to the control valves, the bucket and the hoses, but this year the pump seems to be at fault. The system lifts the assembly slowly and stalls with a heavy weight attached. The pump appears to be the old style: small, square and with a plug on the outboard end. I haven't found a rebuild kit or a replacement so I thought I would post here and ask for advice.

Just replace it with a generic gear pump and mounting foot.

https://www.magisterhyd.com/product/1-70-cid-hydraulic-gear-pump-3-4inch-keyed-shaft-ccw/

TOH

Thank you for the suggestion. If I may ask: is the keyed shaft on the pump appropriate for the flex coupler that mates with the drive shaft? And where could I locate the "mounting foot"? Is that custom fab? I've never had this apart and once I do the tractor is grounded until replacement is completed.

I've added photos of the pump (see image links) https://drive.google.com/file/d/1MzL05mSM16-C3u4_s5nUrBkc1ULV_-2E/view?usp=sharing, https://drive.google.com/file/d/1U2vHFJogz94BR2cRHtpFTRhx-qSJ7mhF/view?usp=sharing, https://drive.google.com/file/d/1cBAVQ5NzbPT7RwBN40BjPr7oDHaBbmkT/view?usp=sharing, https://drive.google.com/file/d/1movJzetMP3fNygxQbB7SJ_hq6Zkbygx_/view?usp=sharing, https://drive.google.com/file/d/1nNJzlWcF1zWy5VI4GnH-omOglNNwxW8p/view?usp=sharing, https://drive.google.com/file/d/1z2xVb_xXdUOFOA9vNRAWWCxxEZtrfI1S/view?usp=sharing

The pump I linked is 3/4" keyed shaft and should slide right into the coupler. Here is a mounting foot - might need some shimming to get the centerline lined up.

Hydra-Mount SAE-A

TOH

Thanks to all for your help with this issue.

-CH-

You are very welcome. That loader will be happier with a smaller pump in the 6-8 GPM range.

Would this be appropriate? Or is the pressure too high?

https://www.magisterhyd.com/product/0-97-cid-hydraulic-gear-pump-3-4inch-keyed-shaft-ccw/

BTW - looks like you have a filter on the pump inlet. If its clogged/full it might be the source of your problem. Check it before giving up on the old pump.

TOH

I disassembled the OEM filter / screen and found bits of rubber < 1/16" and some fibrous material, could be paper or packing material. Screen is in the shape of a truncated cone, mesh diameter appears to be ~ 100 / sq. in.

Interesting design; when I reassemble I will install this.

The filter was added at the time the controls and hoses were rebuilt. The OEM was a sort of "gravel strainer" that probably offered less resistance. I still have it, could replace it.
How much hydraulic fluid might I expect to drain out of the system?

Paper filters on the suction side are generally discouraged. Preferred practice is to have a 100 mesh wire strainer on the suction side and a 10-20u paper filter on the tank return. If that is a flooded inlet pump you will get most of the reservoir capacity out when you remove the filter....

TOH

Thanks again for all this useful information. I have lots of 8N material but nothing on the loader.

I was just wondering if I would need more than two 5-gallon buckets to contain the reservoir contents. Can the hydraulic fluid be re-used or should it be replaced?

I removed the filter cartridge and drained about 5 gallons of oil from the reservoir. The filter itself does not look to be clogged but reading the Wagner manual I realize the filter, which was added by the company that overhauled the controls, should be replaced with the original strainer.

With some effort I have loosened the pump from its mount but not from the drive shaft. I ay have to disassemble the "special sheave", as the manual calls it, to further separate. Are the rubber grommets still available?

I have removed the inlet side hose fitting but not the outlet, as the hose-end side won't turn. At least it hasn't yet. Worse comes to worst I buy another hose.

Thanks again for help.

A little late replying but:

New hoses and portbadspters all around
That special sheave is an oddball. Bushings are available but the Dearborn 192160 sheave with splined hub (192161) ans shaft are vastly superior.

TOH

Having removed the pump I sent it to a local hydraulics shop for inspection and testing. I couldn't budge the setscrew on the Morflex adapter so it went along for the ride. A rebuild is possible but not expected, due to parts availability; they will "test" the pump for free.

I also obtained the "mounting foot" that adapts the replacement pump. I am waiting for a reply from the (replacement pump) reseller concerning dimensions to be sure the pump will fit.

There are pumps available with higher GPM ratings (e.g. 15 GPM): I assume the lower GPM rating is preferred because it gives a more nuanced control of the hydraulics. Is that the rationale?

I moved the tractor out of the barn so it wouldn't block access while disabled, and of course it has rained steadily since. Tarp cover will have to do for now.

The mounting foot is stabdard SAE-A two bolt flange and will fit any SAE-A 2 bolt pump.

The lower flow rating is a better match to the reservoir capacity of the loader. A higher flow rate will decrease the time it tskes for loader to go from full down to full up. Meaure bore andcstroke on the lift cykinders andcwe can calculate thos numbers.

TOH

Thank you again for all of your assistance in navigating this issue.

I have the mount, as mentioned, and ordered the (smaller throughput) pump today.

Your loader looks like a Wagner WM-3 to me. We do have a parts and installation manual for it in our library here.

• Click here to view/download it

Thank you for pointing this out. It does indeed look like a Wagner loader. All this time I've been calling it a Dearborn and can no longer remember why.

And thank you for posting the documentation.

Likely. A big tell is the single center mounted bucket cylinder. Dearborn used dual cylindersvon their designs.

TOH

Loader manual can be found in the manuals section of this site. They tend to be pretty terse and lacking on details. I would expect the reservoir on thst loader to be closer to 5 gallons than 10.

Personally I do not reuse drain oils.

TOH

That would be a good fit. You dont need to worry about high pressure. The loader valve has an internal pressure relief that limits the max pressure the pump will produce. Protects the pump and the loader from damage.

TOH

More photos, linked here, showing pump and strainer:

https://drive.google.com/file/d/1AuyoKrRfGBChVmXvltMtIN88mfDofSbb/view?usp=sharing, https://drive.google.com/file/d/1IJ3tvATryd71NgcYJHzeCLH1lDRdzL-l/view?usp=sharing, https://drive.google.com/file/d/1QVY3kdXxuvU_tti_LLRbX8IRrgGQM40B/view?usp=sharing, https://drive.google.com/file/d/1sHlMdkzqj9cC5cUeR3TjerZMIDRD5yKv/view?usp=sharing