580C lacks digging power

[Delmer]

I'm not any of those guys, but this is a very basic system with a very basic problem. You really need to eliminate all of the simple issues first before anybody can give you any meaningful advice. If the fluid turned milky, then it either has air or water in it. The air would be coming from a leak on the suction side (one of those hoses etc) maybe worsened by a plugged filter or even worse, a collapsed hose. A hydraulic pump that gets air in it won't develop much suction and won't prime itself if it's getting air instead of oil. If the oil is contaminated with water (test by dripping a drop on a surface hot enough to make the oil smoke or burn, if there's water it will sizzle/splatter) then the oil will cavitate worse and the pump will suck worse.

Pressurizing the tank like Tinkerer said will turn those suction lines into pressure lines and hopefully help you narrow down your problem.

It wouldn't hurt to check the filter/bottom of the tank for metal shavings. If the pump went bad, you're going to want to do a lot more work than just swapping out the pump before you run it again.

 

[PAwrestling#1]

what is the best way to pressurize it. Get another plug for the fill res. and install an air fitting?

 

[Tinkerer]

The best way is to use pipe fittings in the fill opening with a male quick coupler in them. Along with a pressure regulator that most air compressors have. Second best is have someone help you by wrapping a rag around a air gun and apply it to the opening. But be careful of going crazy with the pressure.

 

[PAwrestling#1]

Not doubting your advice cuz im doing this test tonight but isnt that tank always pressurized? When I take the fill plug out it always releases pressure and hisses

 

[PAwrestling#1]

or is 10 to 15 lbs more than what that tank would have in it?

 

[Delmer]

Some heavy equipment has pressurized tanks, but I don't think an old Case does. It doesn't have an air compressor or turbo, so where would the pressure come from?

If the suction hose is leaking then it sure could build up pressure in the tank. I like to drill a hole in a cap big enough to put a rubber valve stem in, and use that to fill and check pressure. If you do it that way you can run the machine and see how much pressure it builds up from running.

You mentioned a hose running alonside that has been disconnected, that could be the original suction line that somebody replaced with a hose that wasn't designed for suction, just a guess.

 

[PAwrestling#1]

ok so that i quit bugging the %^$%^ out of you guys im gonna apply 10 to 15 lbs of pressure with machine off and look for leaks then with pressure applied start machine and see if anything can move?

 

[PAwrestling#1]

and if I have a suction line leak would i hear it when applied pressure in tank and engine off?

 

[Delmer]

You'll only hear the leak if you drain the tank and lines first. You'll be looking for a seeping hose, if there's oil in the hose that's what will leak out. It helps to clean the hose ends as best possible and dust them so the oil shows up better.

 

[Tinkerer]

and if I have a suction line leak would i hear it when applied pressure in tank and engine off?

Ifn the system was out of oil you would hear air leaking after you pump it up with air. But I am assuming you have it full of oil. In that situation you should see oil seeping or even gushing somewhere. Do you happen to still have the old filter you took out ? If you do have it, cut it open and look for shiny stuff. Be very careful with the cutting PA,it doesn't sound like you have time to go and get stitches. Have you looked at the hydraulic pump to engine coupling with the engine running ? Maybe the stupid thing is broken and the pump isn't even turning.

 

[PAwrestling#1]

Came home from work with fittings to put together to apply air to filler tank and went up to backhoe and the back bucket sagged over night and was all but on the ground and had to drive it down to my basement door. So started it up grabbed the lever and up it came?? So i didnt loose all hydraulics??? So do I still do the pressure thing in the tank or move onto something else. I will check coupler now.. But would the backhoe still dig if it wasnt working? I mean i would bet I could go out there right now and dig a stump out but it struggles to lift a full bucket of dirt out of the hole especially the warmer it gets. and a really dont think there is any major leakage because I have been watching the last 2 or 3 times digging with it.. The only thing I seen was that swivel leak.. I caught a quick squirt of fluid out of it and then one time it ran out steady stream for about 5 sec. and then quit. but it keeps leaking just not a total steady stream all the time

 

[sheepfoot]

I would first go back and check the quick connects for the backhoe at the rear end, look real good to see if they are still connected good, then take a good look at the pump coupler splines, then looking at tinkerer pic, # 22 cap is where you check your pump pressure, if you don't have the right fitting, remove the cap and drill and tape a 1/8 pipe fitting in the center, have a hose made up with 1/8 on one end and 1/4 on the other about 5 ft long, pick up a wet gauge at 5000 psi, hose should also be a min 5000 psi, yes you can get by with less but safety wise more is better. Start machine at idle and raise loader to the top, read the highest pressure, due the same at full speed read the highest pressure. Most machines if it will build to 200 psi of main relief at idle the pump is not the issue. There could be a nick or trash in the main relief or a power beyond issue with/if the machine has a 4/1 bucket. If your oil level is correct and the breather not stopped up I really do not see a suction issue unless one of those hoses have sucked the inside shut and not allowing oil to flow threw it. Need to get a gauge on it so you Know what pressure your dealing with.

 

[Delmer]

See if the oil is milky when the machine is cold. Use the machine till it gets warmed up/loses power, see if the oil is more milky, see how hot the pump is.

I wouldn't bother with the coupler, every one I have seen only lets go once, they never fix themselves once they slip.

Unfortunately suction blockages are usually more of a problem with cold oil on a cold day...

 

[PAwrestling#1]

the oil is always milky.. im telling ya I drained it sat. and put new filter in oil was nice yellow green color thru sight glass. i started the machine ran all the levers and shut it off. 30 sec to a minute i bet. Milky.. that quick.. grant it i didnt flush everything but for it to turn white that quick?? is that real?? it did it... spline in coupler is turning found test ports everything in back looks good but control valves are a little wet so might have small leak back there but control valve for bucket and test ports and pretty much everything it that location is really wet. when i take those caps off at test ports i take it oil will come out immeadiately?? I cant take one of those off tonight and take it to work with me tomorrow to get right hookups with my gauge and hose? and in my book it shows a tester with two hoses? Im not building that right, just a 5000psi wet gauge with hose. Can you buy these hoses already made up? just buy the correct end i need?

 

[Tinkerer]

grant it i didn't flush everything but for it to turn white that quick?? is that real?? it did it...?

Well PA; If you didn't follow the procedure that we advised and only changed the oil in the reservoir you only removed maybe 1/2 of the contaminated oil. You have to flush all the lines and cylinders with clean oil. So yes your oil will turn milky looking within a couple of minutes after start-up. Does the oil in the sight glass look clear after the machine sits overnight ? If it does your problem is air infiltration.

 

[PAwrestling#1]

no im not saying I did it the right way i know i didnt but i didnt have the money for 20 more gallon of fluid last weekend.. but now with a new pump if i need to get a new pump i will be buying the extra to do it the right way this time.. So yeah i wasted 20 gallon of fluid.. i just thought a new filter and 20 gallons of new fluid would improve my performance and it didnt at all.. No its stays milky 24/7 no matter if i let it set a week

 

[PAwrestling#1]

If i were to have a bad pump i got other issues right as far as water/air in fluid or does a bad pump do this?

 

[ManicACMechanic]

Still sounds to me like a clogged or restricted suction line or screen(if it has a screen). Whining pump is a good clue to this.Hole in suction hose (it can have this and not leak any fluid at that spot). Pumps don't generally work one minute, then fail, then start working again. Any of these problems I (and others previously) describe can and sometimes change with the temp of the oil. Aerated oil looks milky. I'd take some of that oil and boil it at 300 degrees F. and see if it steams water vapor out.

 

[Tinkerer]

The first thing is you need to determine if you have water and or air in the oil. If it is water, whatever you do don't install a new pump until you completely flush the ENTIRE system and clean the hyd. tank and install a new filter with the old pump still in place. After you do all that then you will find out fairly quickly if air is getting into the oil. Reread post #7 here ;
https://www.heavyequipmentforums.com/showthread.php?37500-Hydraulic-fluid-drain-and-filter-change

 

[handtpipeline]

I don't mean to dampen spirits, but we had 3 580c' that we bought brand new in about 1977. Good loader tractors, but as far as the backhoe were gutless wonders. From the day they were new until we traded them off (one got stolen) We actually kept 580b's when we traded the remaining c's for d's in 1981. Case worked on them numerous times, our mechanic worked on them... The only part on the backhoe that appeared to have any power was the bucket curl. The boom wouldn't pick the back of the machine up if the front was picked up with the loader. If you had the loader in the air, you could pick the back end up. Stick would stall easily trying to fill the bucket, they would not attempt to pick the front of the machine up if you got ahold of a good size rock... Another thing was trying to move yourself around. It better be pretty flat ground or the stick didn't have enough power to push or pull you. Swing was weak too when you were trying to set yourself over a ditch or something. I was young then, but I remember how horrible they were. And most of the operators would choose the older B's we had over the C's...