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Re: Case/Davis trencher backhoe

Posted: Wed Apr 12, 2023 9:08 am
by Eugen
@Spike188 The oil that came out of the valve, which, by the way, was quite a lot, was very clean. All the spools on this one move in both directions easily and the spring brings the spool back to center. I cannot feel on any of the spools a float of any kind. Is there?

I'm very tempted to open it up and replace all the o-rings, just to know it's been done. On the other hand, it seems fine, and the only risk I see not doing it now is the $30 shipping I'll pay if I do it later if necessary. Really on the fence on this, as you can see. :geek:

Re: Case/Davis trencher backhoe

Posted: Wed Apr 12, 2023 9:37 am
by Spike188
@Eugen you unit appears to be weather degradation where mine was abuse. I would inspect the exposed areas of the spools. If they show little or no signs of rust I would be inclined to leave them alone. But now that the piping is easy to remove, it is prime time for service.

Re: Case/Davis trencher backhoe

Posted: Wed Apr 12, 2023 9:59 am
by DavidBarkey
Spike188 wrote: Wed Apr 12, 2023 9:37 am @Eugen you unit appears to be weather degradation where mine was abuse. I would inspect the exposed areas of the spools. If they show little or no signs of rust I would be inclined to leave them alone. But now that the piping is easy to remove, it is prime time for service.
I agree with Eugene .

Re: Case/Davis trencher backhoe

Posted: Wed Apr 12, 2023 3:43 pm
by Eugen
Very little rust if any, on the exposed part of the pools.

Here's the list of o-rings and seals ordered, and prices in CAD from hercules, to give you an idea. To my best ability, the list is complete and enough to refresh the following cylinders: boom, dipper, bucket, swing, and stabilizers. I chose all o-rings buna-n durometer 70 (series 568 on hercules). All the back-up rings buna-n durometer 90a (series 574). For wiper rings I chose MCN (metal clad rubber), which is what I think was installed originally.


Once the parts arrive I will install them and at some point will test.


Screenshot 2023-04-12 at 15.14.22.png

D100 backhoe seals list hercules.pdf
(28.85 KiB) Downloaded 291 times

Re: Case/Davis trencher backhoe

Posted: Wed Apr 12, 2023 6:31 pm
by thebuildist
Thanks for posting that, @Eugen

What a helpful resource for others with backhoes that may need servicing.

And I still cannot actually believe that may include me soon!

Bob

Re: Case/Davis trencher backhoe

Posted: Thu Apr 13, 2023 9:45 am
by Eugen
The bottom of one of the stabilizers must've stayed dipped in mud for a long time. All parts were welded together by rust. The pin did not budge with heat and banging. Fortunately there was enough clearance to cut it off with the sawzall. The rod has deep rust on a length of about 3" from the tip. Might need to replace the rod.

021151B2-398C-4115-8DE8-EAF6AD35BC66.jpeg

Both rods have rust damage on the ends. Looks like one had been repaired, is longer and a lot more rusted than the other. Would be nice to replace them. @Spike188 and @FUTZ do you have any suggestions where I could find replacements?

57BADFE7-E56E-4937-94DA-8042E7FD9B36.jpeg

Re: Case/Davis trencher backhoe

Posted: Thu Apr 13, 2023 11:06 am
by DavidBarkey
New ones can made from chrome shaft . I know Western Hydraulics does it in our area . There maybe others shops as well . Call around , you maybe able to get it done cheaper in the big city .

Re: Case/Davis trencher backhoe

Posted: Thu Apr 13, 2023 11:23 am
by Eugen
DavidBarkey wrote: Thu Apr 13, 2023 11:06 am New ones can made from chrome shaft . I know Western Hydraulics does it in our area . There maybe others shops as well . Call around , you maybe able to get it done cheaper in the big city .
Thanks Dave!!

Re: Case/Davis trencher backhoe

Posted: Thu Apr 13, 2023 2:16 pm
by Eugen
The parts from hercules, ordered yesterday, arrived! Yay!


9E7660FF-C3FA-4CC6-8E4E-0178C2678A2C.jpeg

Re: Case/Davis trencher backhoe

Posted: Thu Apr 13, 2023 2:18 pm
by thebuildist
It may be easier and less expensive to replace the whole cylinder. Not necessarily, but maybe. I'd measure the cylinder size and stroke and look them up on Ebay and SurplusCenter. The affordable cylinders are kind of hit and miss for available sizes, but you may get lucky.

Bob