400 super diesel hydraulics

CountryCase · Apr 29, 2014

I have just purchased a 400 super diesel. The hydraulics are very weak. I'm sure the pump needs rebuilt. Does anybody know where I can get the parts or do you know where I might find a good used one?

Adirondack case guy · Apr 30, 2014

Are you sure the pump is bad, or is the relief valve weak. I would be doing a pressure test first to check the valve. A flow test would tell the whole story, but most people donn't have a flow meter. A simple 2000# gauge plumbed to a male coupling will get you started.
Loren

EliG · Apr 30, 2014

Another thing to check would be the orings that seal the pump to the tubes that go down into the hydraulic reservoir. They get old and can crack allowing the pump to suck in air.

The tube in the reservoir has a screen on the end of it. It may be plugged with debris. You can check that by dumping the oil and removing the cover on the filter and the filter. The filter is on the back side of the reservoir on the right side. It has 3 bolts with a pipe plug in the center. The filter can be cheaned and reinstalled assuming its there.

Some folks will add a quart of 85W-140 to the oil to help deal with wear in the pump.

Good luck.

Eli

CountryCase · Apr 30, 2014

I pulled the relief valve. had $1.50 in quarters shimming the spring. Now has $1.75. works a little better. I will get a gauge an put on it. Thanks for the info

CountryCase · Apr 30, 2014

I pulled the filter. The screen wasn't plugged but the oil was BAD dirty. I will give the heavy oil a try. I will take it apart this summer to check the O rings. I have it on a disk right now an don't really want to take it apart unless its a must. Thank you for the info

400 super diesel hydraulics

CountryCase

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Adirondack case guy

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EliG

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CountryCase

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CountryCase

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