Hydraulic controls work at idle only. I have 3000psi when holding loader bucket at curl so I’m assuming my pump is ok, but as soon as i increase rpms the pressure drops to zero. I removed the main relief valve from the loader control to inspect and clean, but didn’t look bad at all. Any suggestions appreciated! Thanks
Hey Gigdigitty what is s/n of machine? Also is this a pilot hydraulic operated machine or standard mechanical operated machine?
Hey Coy, It’s a case 580 super N loader backhoe with mechanical controls and power lift. I’m thinking i have pump related issues. After removing the floor access panel with the pump right there at the opening i can hear some rattling when stepping on the throttle. Not sure if it’s gear driven but it’s acting like a keyed sprocket come loose perhaps. I guess pulling the pump and tearing into it should reveal the issue. What do you think?
Did you change the hydraulic filter and cut it open to look for crap in it that shouldn't be there ?
I didn’t cut it up but i had it sitting upside down in a clean clear jug for over a week now and saw no crud. Shined a light in the tank and that was clean also. I have a hunch my pump is going bad, it’s making some rattling noises and gets hot to the touch within 30 mins of use. I noticed the mechanical up/down loader control seal is leaking when activated. Is it possibly sucking air through that leak causes cavitation?
Your noise could be the drive for the pump. 3000 psi at idle then dropout at high idle and odd sounds like slipping. Does it spin the tires into a pile?
Mike, Yes, i get 3000 psi at ldle when i curl the loader bucket down and hold it there, then release it goes to zero. Sorry I’m new to this sruff, Not sure what you mean about spinning tires?
What does the pressure read if you curl the bucket at idle then rev it to full throttle. It should go to zero when you release. What are the pressures for other things like dump and boom both ar idle and full rev?
I believe it went to zero as soon as i went to full throttle. I can lift loader bucket at idle, but then when i step on throttle to speed it up the hydraulics completely shut down. Frustrating to say the least!
It may be the drive coupler for the hyd. pump in tranny. It'll work until you put pressure on it. This is very unusual for these pumps that's why they started mounting them on the back of tranny because front mounted pumps would strip out drive coupler. You would probably find metal in tranny filter rather than hyd. filter.