Case 580B backhoe hydraulic troubles

[dpuckett]

Friend of mine has a 580B Case Backhoe (early 70s?) that is spewing hydraulic fluid out the vent. I checked all the low pressure connections and tightened a few worm gear type hose clamps, but it still leaks. Only leaks when you put a load on the system; idlinig, the fluid stays put.



With the fluid coming out, there are LOTS of tiny air bubbles. WHat gives? Where should I start looking? I was thinking a return line (?), but have NO idea where to start looking. Irvin is going to ask the guy at Case Mon what gives, but was thinking there are a lot of guys here that combined, know almost everything.



THanks,

Daniel

 

[nickleinonen]

how's the pickup line/tube? if it's getting air into the oil, the pump is cavitating. are all the inlet pipe's nice and tight?

 

[dpuckett]

No leaks that I could see in the area of the pump; and the pipes seemed tight. The pump is on the front of the crankshaft, and has some lines/ tubes going to it from the reservoir, which is the support arms and part of the framework for the front loader bucket.



Pump cavitating... ..... Wonder how much that is. Doesnt look too hard to replace, though.



Thanks

 

[nickleinonen]

the pump might be alright, but if it's drawing air from somewhere before the pump, it will just foam it up... doesn't need much air to make it cavitate

 

[B.G. Smith]

The pump has a relief valve that is supposed to maintain a constant pressure in the system, any bypassed fluid will be sent back to the reservoir. The valve might be defective/broke spring, something stuck in it, etc. causing excess flow back to the tank, causing excess aeration in the tank and the leak. bg

 

[dpuckett]

Thanks for the replies, guys. Turned out to be one of the supply hoses worn from the inside out. IT was real spongy and had a few rips in the inside. Replaced the hoses, and so far so good.



-DP