Weird Hydraulic issue

[dieselsamurai]

Moved my digger last weekend as needed access to somewhere no issues at but before i did i noticed the oil was very low and a patch underneath its always dripped a bit but i thought it didnt look like 2lts or more anyway topped it up and moved no issue.
Started it up yesterday moved it about 20ft then noticed oil starting to pour out of the filler cap but really frothy stopped it but it carried on for a bit , afterwards oil was back to normal level



Makes no sense to me where did the oil go before and why so frothy , its never done this before and ive had it 20 years

any ideas?

 

[bricol]

20 yr old suction hose letting air in, oil to leak out?

 

[dieselsamurai]

20 yr old suction hose letting air in, oil to leak out?

its a 2 year old silcone one but ill check it , its possible but doesnt explain where oil disappeared to

I redid all the hydraulics a few years back , mostly new pipes and a triple pump in place of the big single one

 

[Bravheart]

Does it have an oil cooler? Might be water in that oil

 

[JOEPRO]

I have seen this before in car hydraulic steering systems. It's a bit of a weird phenomenon whereby if the fluid is too low it can foam up and overflow.

Topping off fluid to correct level once the foam settles out again normally cures them.

 

[dieselsamurai]

Does it have an oil cooler? Might be water in that oil

its one mounted in front of the main radiator so no direct path for water

 

[dieselsamurai]

I have seen this before in car hydraulic steering systems. It's a bit of a weird phenomenon whereby if the fluid is too low it can foam up and overflow.

Topping off fluid to correct level once the foam settles out again normally cures them.

Weird thing is oil is back to correct level now just blew out most of what i put in last week

 

[Rannsachair]

In the past I have seen foaming from contamination or a blocked filter or collapsed hose causing cavitation.