Hey guys, I have a wood processor that I would love to hook to my 50G but it requires a case drain that my Deere doesn't have. How much trouble is it to run a case drain? It does have the 2 auxiliary hook ups as well as the diverter valve. Thanks in advance!
You can run pipe a hydraulic hose with a quick coupler along the boom and tapped back in the tank for a drain back.
Should I be going thru a filter?
Anyway you prefer but make sure you plumb case line such that it doesn't have any restriction in between (valve/cooler or anything). plumb directly to tank.
Guessing the processor has a hydraulic motor so it's essential to have a filter on the casedrain. When hydraulic motors fail the debris returns through the casedrain, without it the entire hydraulic system will get contaminated and usually requires a total tear down as part of the fix. If your digger has a casedrain on the slew motor or track drive it could be plumbed into that.
Sorry I beg to differ, case drain line should have clean connection directly to tank without restriction. No filter in between.
What happens if the hydraulic motor goes out?
If the motor fails, contamination is handled by the return filtration and tank management, but restricting the case drain with a filter risks over-pressurizing the motor and causing immediate catastrophic seal failure. Case drains must remain unrestricted to tank.
The case drain must be Free flowing, Low pressure (typically < 1–2 bar) and Direct to tank If you add a filter in between It creates back pressure, Motor shaft seals can blow out, Internal leakage increases, The motor can catastrophically fail even when healthy, On piston motors - the rotating group loses lubrication and cooling Most motor manufacturers (Rexroth, Danfoss, Eaton, Parker) explicitly state: Case drain must have unrestricted connection to tank.
So I put 4500hrs on a machine with a 90 series 100cc Danfoss pump without any problems including 2 motor failures. It had a return flow filter which had bugger all debris in it and a casedrain filter which was chocker block full on both occasions. Without a casedrain filter I would have been up for the cost of 5 new hydraulic pumps twice and about $ 50,000 twice It also had 2 H1 Danfoss pumps for the track drive each had a casedrain filter and when a track drive lunched guess where the crap was found. BTW those filters didn't cause the failures.
Every excavator I have worked on has the case drains routed through a case drain filter. They are not routed through the return filter. Case drain volume is very low and delta P across the filter is minimal. Delta P across the return filter can well exceed 30-50psi.
So what you're saying is I definitely need to run it through a filter?
Yes, that exactly what Ben has written and what I advocate.
Thank you so much for the information guys, I think I'll run it through a filter.
Too often people put too small of a case drain filter with small fittings which increase pressure. Have seen a skid steer that operated a snow blower that the motor grenaded and the big and the finest pieces possible all went back into the tank with out no filter to stop it. Machine got sold after, so who knows what happened to it. The filter is the last protection before landing in the pump suction. Simon C
Please see the attached recommendation for not filtering case drain line. I agree there can be machines having case drain filters, but filtering prior to case drain is the rightful choices.
AS stated restriction is minimal. The benefit is that in the event of a failure or as wear occurs it keeps it from contaminating the rest of the hydraulic system. It is conceivable that a $1000 motor could cause $100k+ worth of damage to an excavator.
Ok