Hello all I am new here and glad I found this Forum. I have been looking all over for a solution to my problem and have came up empty handed so I hoped someone here could help. I have a 2002 Case 580 M Series I with 1700 hrs. I blew a low pressure line from the hydraulic filter to I believe the oil cooler. Spliced the line back together and replaced the lost oil ~5 gallons. Hooked my homemade gauge and bleeder to the pressure side quick connect to get the air out on the pressure side. Went to start the machine and had no pressure at idle. Gauge is reading about 100 psi at idle. When engine RPM's are increased to 2200 the gauge reads 200 psi. I put some air pressure on the main tank hoping that it was possible air locked with no different results. I looked at the owners manual and it mentioned a "Pump Replacement Procedure" but only said see dealer or service manual. I am hoping I have missed a step and the pump hasn't gone bad. It was working fine before the hose blew. The pump isn't and hasn't made any noise and I don't believed I starved it before It was shut off after the hose blew. Please help TIA
Are you activating a function? These are open center systems and you won't build pressure unless you're activating a valve spool to cut off the normal flow back to tank through the return filter. Losing some oil from a return side line shouldn't affect the system unless you ran it completely dry and the gear pump took a vacation.
Did't realize they were closed center. No i was not activating a function. I will try that in the AM
He said they were "Open Center".
Is it possible your new splice is a smaller id than the the hose you repaired and it is restricting the flow ?
No I used a 3/4 barb to barb fitting to splice the hose. I wouldn't think that would restrict it enough to make a difference.
Is it possible the barb has damaged the inside of the hose and the inner liner is folded over as a result ? Unless something cut the hose a new hose should maaybe have been installed. Failed once /fail again. It could be a collapsed hose on the suction side of the pump. Did you replace the hydraulic oil filter ? Did you run the pump dry when the hose burst Like Lantraxco asked.
The hose got damaged by a stick so it was only nicked. Dont believe the barb damaged the hose but anything is possible. The suction side is a medal tube with two short rubber 90's on each end. I do think the pump went dry for a few seconds but I don't know for sure. I lost 5 gallons of oil from a 15 gallon system so I don't think it could have gone dry. I replaced the filter.
You say that you have a gauge and bleeder hooked up on the pressure side of the pump. When you opened the bleeder did any air bubbles or foam come out. Did you get a good solid stream of oil out of the pump ?
Yes getting a good solid stream of clean oil no air or foam.
Did you do as Lantraxco suggested In regards to activating a couple of functions with the engine at normal operating speed ? Like both the loader or any of the backhoe operations. If you did and nothing happens I would be thinking the pump has a problem. Hopefully one of the pros will read this and offer an opinion.
The pressure you are reading is the resistance across the tubing, hoses, valves, and filter
DVFarms - The machine is still operational? Do the hydraulics load up the engine when cylinders reach the end of stroke? Bleeding air from the hydraulics is not required on a 580M.
Finally got a chance to check the pressure while performing a function and I am getting 700 psi @2000 rpm.
Yes it is still operational. There is no difference I can tell between now and when it was operating normally on the amount of engine load when the cylinder reaches the end of its stroke.
So what is it doing that's not normal now? I don't think I'm the only one who can't see anything wrong here.
It doesn't have enough hydraulic pressure to operate any function at idle. At 2000 rpm the machine is able to move all functions but doesn't have enough pressure to dig or lift a load with the bucket also the outriggers won't lift the machine.
If there is nothing restricting the supply side of the pump, I would be buying a new pump. Others may have a different opinion.
I would pull the pump and disassemble with the service manual in my hands. Of course if the OP has a service manual, he could follow the instructions on how to test the hydraulics....
So is this pressure with the function stalled? If it's still moving then it's not an indication that the pump is bad. This doesn't add up to me. Any possibility one of the metal lines bent enough to crimp a bend? The pump should heat up real fast when it's stalled if it is really bad, and there's no leakage somewhere else that's causing the low pressure.
If by stalled you mean held in active position then yes. No lines are crimped and no leaks, everything was working before the line blew.
Stalled: held in the active position and the cylinder isn't moving. Like at the end of the stroke, or stopped against something. About the line, it was damaged by a stick and started leaking, leaked out five gallons and was shut off. correct?
It was damaged most likely by a stick at some point. The damaged spot was were it blew. I was digging with the hoe at the time it blew. I shut the machine off when I smelled hydraulic fluid. The hose that blew is the one from the oil filter to the oil cooler, which I assume is the bypass return line not sure. I fixed it with a hose barb fitting since it is a low pressure line and refilled the system with oil to the full mark. After repairing the line I bled the air out on the pressure side of the pump. Got a good steady flow of oil no cavitation. Ran the machine to operating rpm's and cycled the cylinders multiple times. Checked oil levels and added oil to the full mark. In total I used a 5 gallon bucket.
So this is with the function activated and either the cylinder stalled against something, or at the end of the stroke?
Yes bucket cylinder at the end of its stroke.
OK, it won't move the stick at idle and won't work at 2,000 rpm, with 700 psi. Doesn't look good for the pump but I wouldn't give up yet, but I'm not the expert either. It just seems like the pump wouldn't be harmed by seconds or even a minute by an oil leak, it won't be dry and won't have much pressure. I'm wondering out loud if there could have been something that came through the system that caused the hose to blow and a relief to stick open around the same time, rather than the hose break causing the issue? One rough way to test it is to start it on a cool morning, after a minute hold the bucket to the end of the stroke for 10 seconds and shut the engine off with the valve still activated. If either the pump or control valve is warm but not the other, then the warm one is what I'd take apart first.