What is the best way to...................

[DIRTROAD]

...........Plumb a "case drain" on an excavator. I just bought an attachment to run on my excavator and it requires a 1/2" case drain line.

Can I just plumb it back into the return line or does it need to go straight to the tank?

[Nac]

I am pretty sure it has to go back to the tank. I have to do the same to mine for a sheet pile vibrator I am getting.

[abnerlol]

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[willie59]

That's a good question dirtroad. Typically speaking, the case drain of any hyd motor is to provide a way for internal leakage of the motor to drain back to tank, it would be a very low pressure of oil. The problem you may encounter by tapping into "return piping for the attachment" might be the return flow from the attachment, through the piping size on the boom, causes a certain amount of PSI pressure in that return circuit because of the size of piping. This may be a greater pressure than what the case drain is tollerent with, thereby, increasing pressure inside the case of the driving motor. Without noodling out all the physics involved, it would be better for the attachment motor to have a designated case drain line to tank to relieve case drain oil. Can't say that's written in stone though. :)

[DIRTROAD]

Thanks, I am understanding the concept of a case drain a little better now.

I guess I'll just run a dedicated line back to the tank and filter it.

Any suggestions on the best material to use?

[OCR]

I am pretty sure it has to go back to the tank.
it would be better for the attachment motor to have a designated case drain line to tank to relieve case drain oil
Yup, Nac and ATCO are right, DIRTROAD... at least, according to this.

Might give you some insight on your filter questions, too.

http://www.insidersecretstohydraulics.com/case-drain-filters.html



Here's the 'technical library' page, DIRTROAD... just click on the blue links below 'MAINTENANCE AND TROUBLESHOOTING'... some pretty decent information on it.

http://www.hydraulicsupermarket.com/technical.html




Hope it helps....


OCR

[DIRTROAD]

Excellent links OCR !!!

That helps me wrap my head around the function of a case drain and what I am going to have to do.

Thanks

[OCR]

Excellent links OCR !!!


Thanks, DIRTROAD... glad to hear you got some useful information... :thumbsup



OCR... :)

[willie59]

You got it OCR, much the same reason you typically don't connect the case drain line to the tank return line from attachment, you don't want to increase pressure on the case drain line. ;)