Loader sounds like cavitation

dsc csd · Sep 20, 2015

just purchased 656 farmall with cab and loader. everytime it starts it makes a whining noise which seems to be coming from the hydraulics. it stops in about 10 to 15 sceonds and then seems to be fine. wondering if its in the pump itself or a seal?

Thomas · Sep 21, 2015

Not really sure,but if the seal was going bad wouldn't there be signs of leak?...maybe early signs pump its self going bad...bearings.

George2615 · Sep 21, 2015

Welcome to TBN...........
Since you just purchased it, when was the last time the filters and fluids were changed.
Fluid level could also be low.

Jerry/MT · Sep 21, 2015

If it's a high frequency squeal, the pump is most likely sucking air. It's bit hard to cavitate oil in a gear pump. is your fluid level low?

dsc csd · Sep 21, 2015

changed all fluids and filters first thing, everything seems to operate as it should. fluid is a little below full mark by a quarter inch. didnt think that would be low enough to hurt anything

Jerry/MT · Sep 22, 2015

Having the oil a little bit low should not cause a pump to suck air. A loose or cracked pick up tube will however. The fact that it goes away tell me the pump loses prime after the tractor is shut down and regains it on start up after 15 seconds. It's probably a small air leak and I 'd still suspect the pickup device. It's nut critical since it regains its prime but its something to monitor over time to see if it worsens an then you'll have to take some action. How difficult is it to get to?

dsc csd · Sep 22, 2015

havent had a chance to check it out yet jerry/mt. will dive into the old shop manual when i come off of rotation at the mines. i had had the thought that could be a possibility as well. being fairly new with internationals i havent experienced working on the hydraulics yet.

JCByrd24 · Sep 22, 2015

There are yanmar models that lose prime on sitting. The hydraulics don't necessarily whine on startup, but there is a delay in hydraulics. My thoughts would be that it is not critical if there is a few seconds of whine and then no issues whatsoever. I would fill it right up to full and see how that goes, and continue troubleshooting, but don't lose sleep over a few seconds of whining.