I have a 1996 580SL. All of the hydraulics seem a little weak but get slightly worse when hot. Also when you swing the boom either direction, it bogs the engine. But if you open the swing valve all the way up, it frees the engine. I had the swing cylinders rebuilt and all of the valves o-ringed and checked out. The guy said he couldn't see a problem in the valve. Luckily all this needed to be done anyway because it acts exactly the same as it did before I "fixed" it. I've talked to some pretty good mechanics but everybody seems to be stumped. I'd really appreciate any suggestions.
Has the hydraulic pump been looked at/tested (pressure/flow)? Adjustments could be needed or it could be tired. Also doing some troubleshooting to make sure the valve is not bypassing will help you out. Depending on who rebuilt the valve you could still have problems with it, I have had this happen to me in the past A rebuilt spool valve was inproperly repaired and had massive amounts of internal leakage making the pump work overtime and my funtions not. Any hydraulics guy should beable to test your pressures and flow.
Trying not to steal a thread but i could use some help changing the rear bucket hose on a 580k.?
Your a junior member now stangman893, you can start your own thread now. BTW, welcome to the forum. :usa jbofky, that's a curious problem you have. When you say things slow down when it gets hot, just how hot is the oil getting? If you (carefully) place your hand on the hyd tank, is it warm, really warm, or tries to burn your hand in just a few seconds? The more detail you can give about the various operations will help someone possibly determine what might cause your problem, such as, how does it work when it's cold? Does all the loader functions work somewhat ok? The only function you described having a noticable problem was the swing. The 580L used a gear pump, I don't think it's a load sensing system, but haven't looked at all the components yet. I can't see how the swing would be the whole of your problem, since when your not using swing, it's having no effect on system. If you can give more details might help.
As far as the loss of power when the oil gets hot it could be the main relief is set alittle low or the seals leaking on the relief valve. If the hydraulics are slow or get alot slower when the oil gets hot it is most likly the hydraulic pump is getting weak. As far as the swing problem it sounds like you have an early 580SL that has the priority swing system. The symptoms you describe are normal for these machines. When you barly stroke the spool you are opening the pressure port on the valve and the return port is still closed until the spool is stroked further and it is dead heading the oil in the swing circuit until the spool is stroked far enough to let the return oil go back into the valve. This was a comman complaint with these machine and will also overheat the oil if the operator is feathering the valve alot.
I didn't specifically check the temp. of the tank but I'm pretty sure that it gets uncomfortably warm. The cylinders get very hot to the touch after being worked hard. When cold, it has noticably more power than when it warms up. It weakens enough when hot that you can't push into a pile of dirt while operating the loader. I have to clutch the tranmission before it has enough power to lift and curl the loader when loaded heavy. Everthing else operates smoothly without bogging the engine, including the loader, unless you're trying to swing. If swinging, it pulls pressure from all other functions and slows everything dramatically. A mechanic at work told me it may be getting the fluid too hot and foaming it, but that still doesn't explain the swing problem. I changed all of the fluids and filters when I bought it and used Rotella hydraulic fluid. And he's thinking that the pump is still pretty good since the engine will bog with the swing problem. He's says if the pump was worn it would bypass the fluid without bogging the engine. The only backhoes I've ever ran are a worn out 480F and a John Deere 310SJ that has only 600 hrs. I've been comparing it to the 310SJ so I may be asking too much of it. Thanks for the help and bearing with me. I'm no mechanic, I just know how to run and grease it.
Your machine has a 2 section pump. The large section is a 25gpm pump that goes to the loader valve and then to the backhoe and back to tank if no functions are being used. The small 9 gpm section goes to the swing section and then to the rest of the backhoe sections if the swing is not being used. The real early machines also had priority on the extendahoe if so equiped. It sounds like the small section may still be alright since it bogs the engine like normal but the large section may be weak since you say it does not bog the engine. The 25 gpm pump should bog the engine alot more when using the loader than the 9 gpm pump does when swinging. Also the if the boom, dipper, bucket or stabalizers are deadended the engine should load down even more since you are loading down both pumps.
If your getting uncomfortable heat on hyd tank, you have something bypassing oil. Could be worn pump, failed or improperly set relief valve, or failed o-ring on relief valve. I'm with Goose, I'd be pulling that main relief first and checking it out. I think your swing is a seperate and different issue. Goose knows way more about that than I do.
Without Tee testing the entire system with a flometer you can only speculate as to the problem. A good technician with a tee test can evaluate every system on the BH/LDR in a matter of minutes. At our shop every new Hoe gets flo tested and the results filed for future reference if a question arises about a system performance issue. Just reflow the machine and compare to the original test results. Stops or confirms operator complaints about a change in digging performance. If I were to speculate as well the pump sounds like it is getting some internal leakage, there has not been a large amount of failures on either pumps or main reliefs, Hire yourself a good tech with a flowmeter and specify a tee test and he could also chech each section of the pump seperately although it requires a seperate hookup.
Goose is on the right track, sounds like a swing/extendahoe priority valve is installed on that machine. Typical symptom was if you feathered swing or extendahoe it bogged the engine down which also created a lot of heat. Back when this unit was in warranty the sections should have been changed out. You got a new swing, extendahaoe, boom and inlet and outlet section. The problem with the priority system was that the pump supplied full flow to the function regardless of demand, so thats why the engine bogs when feathering. You should be able to tell easy enough if it has priority flow there will be a small sensing line to the extendahoe and swing section. Bad news is without changing sections you will have the problem. Just curious does your hood have vented panels or solid panels? The L series had many upgrades and wondering if it still has priority swing what other upgrades did they miss?
case 580sl problem What components would have to be replaced to get away from the priority swing problem? Would the cost outweigh the benifit? Thanks
The costs would not be worth the bother. Inlet , outlet, swing , boom and extendahoe sections need to be changed. If they are even available they are about $1200 a section. The swing/extendahoe priority did bog the machine down and could cause hydraulic oil to over heat. Typically this would happen when you were working in a confined swing area ( feathering swing) and it was hot outside. Swinging full speed caused no problems. Case added vented hood panels after production to help with the heating. Main relief problems were fairly common as well.
I hate my priority swing I have a early SL that has priority swing and i hate it.The engine labours alot more and uses alot more fuel.I love my backhoe but I have thought of trading it because of the priority swing.
did it do it befour you changed the oil? cud b the oil case uses there own oil very thin.they use same oil in trany rear end and front end case tch
weak backhoe 580c sorry for my lack of sense on how to post but Im having a simular problem on a 580c that I just purchased.All the functions of the backhoe seem to have good response,but when I try to dig I can hear the valve relieving.I have replaced the filter with no notable improvement.The person I purchased it from claims he didnt have any problems.Im not sure exactly where I can try to adjust the relief or if I need to replace the pump it appears to be the original.Also the loader appears to be strong with no problem with loads.Thanks for any help
just a thought some of these machine have an aux hydro system---hoe-pac,breaker,ect.if it's an aftermarket valve thats electric controled it may be stuck on..shorted wire.. wouldn't afect loader just back-hoe
Thanks Doc That I can trouble shoot as long as I can find the coil
coil in loader control valve Can anybody explain to me the function of the coil located in the loader control valve? I have a Case 580C I assume it is a 12v coil it is polarity sensitive,When i energise the coil I cant tell any difference in the function .Im trying to find the cause of my backhoe being relieved under pressure.I can hear the fluid being bypassed in the area of the loader valve when the hoe is under pressure.Thanks for any help or suggestions
Vatorguy, welcome to HEF! You have 3 posts now, you should be able to start your own thread. That solonoid is for loader bucket leveler - not your problem. Could be a main relief pressure setting - you need a test gauge for that. Assuming you have a 'parker' loader control valve (monoblock) - good idea to check power beyond - item 11 below - (oring & back up 13&14)
Good Day Alrman One of my best friends is an Aussie Thanks for the info I do have a pressure gauge Im very familiar with setting relief pressure on a hydraulic elevator but not a backhoe Im comfortable adjusting it with the right direction.Thanks for your help
if you do have AUX hydro system in the machine it would be located somewhere back by the loader control valve. i have also seen flow control valves mounted at differn't locations that have a small handle that you would use to set the flow for the attactment. if the valve got damaged by a rock of somthing and the handle was missing it could get overlooked....been there
580c bachoe hydraulic problem when I put a strain on the backhoe I can hear the oil being relieved in the loader valve.Is there an adjustment pocedure for the relief?
vatorguy, there are different loader control valves - which do you have? monoblock - as pictured above on post #19 segmented - individual sections for each circuit & bolted together
580c bachoe hydraulic problem It is monoblock.