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Case 650K Series 2 "Charge Pressure Low" light

mleto1

Member
Joined
Mar 4, 2016
Messages
23
Location
Louisiana
I have a Case 650K Series 2 machine with 1100hrs. The machine had sat-up a while before I purchased it. GaryHoff and a couple others helped me tremendously with some electrical issues when I first purchased the machine. I've used it sparingly in the last few months with no issues, but I'm rarely using it for more than an hour or two at a time.

Anyways, while clearing roads at the hunting camp this weekend I noticed the coolant temperature and hydraulic temp kept creeping up. It did not get in the red, but was pretty close to it after 2-3hrs of working it. I would have to stop and let it cool down every so often. Towards the end of day I also had a "charge pressure low" light come on and a buzzer. When the light came on I shut down the machine. After waiting a couple minutes I would re-crank and work a while, but the buzzer would eventually come back on. I did this several times before going park the machine. Even when the light came on the machine never felt weak at all. I also developed 2 cylinder leaks while working, so I was concerned that maybe the hydraulic fluid was old and breaking down?

I went back the next day and changed my hydraulic oil, both filters (hydraulic and hydrostat). I also cleaned the radiator and oil cooler (left side of radiator) with water. The machine did seem to run cooler, but I still noticed the hydraulic temp would creep up within 2 bars of the red after running a while. Especially when I was tracking the machine faster (50-60%). When pushing and tracking the machine at 30-40% it seemed to stay a little cooler. I had the (low charge pressure) light flicker on a few times when I hit the decal pedal to move into reverse. And again later in the day the light did come on. I could kill it and re-start in less that a minute and it would go away for a while, but eventually came on again. My hydraulic oil level was always roughly 2/3 way up the sight glass. I checked for fault codes, and had none.

Any idea what could be going on? I know my machine has the diagnostic test ports to test pressure, but I'm not sure what kind of connector I need to hook-up to that. The charge pump is built into the hydraulic pump on this machine correct? Is it possible to have that part failing with such low hours?

Also, the next day when I went to unload it from my trailer I had a transmission fault light come on. Code 4311F. I didn't let the machine warm up before moving it, so I don't know if that could have anything to do with it.

Any help would be greatly appreciated!
 

hvguy

Senior Member
Joined
Sep 11, 2016
Messages
384
Location
Conroe TX
From what I briefly read, there is a charge pump (gear pump) that supplies oil to the hydrostatic drive, the computer compares pressure with engine RPM, perhaps there is a regulator or diverter valve that's keeping the pressure too low?
 

GaryHoff

Senior Member
Joined
Feb 25, 2009
Messages
810
Location
Alberta, Canada
Occupation
Heavey Equipment Mechanic
You should check your charge pressure. Should be a minimum of 360psi at a idle. Check with machine hot.

Your test port fittings should be #4 Jic, or the flat face test couplers. Should be available at your local hydraulic shop.
 

mleto1

Member
Joined
Mar 4, 2016
Messages
23
Location
Louisiana
I ordered the flat face test coupler, and will have it tomorrow. I should be able to check it tomorrow evening.

Thanks!
 

mleto1

Member
Joined
Mar 4, 2016
Messages
23
Location
Louisiana
I alologize for the delay. The lift cylinder was dripping so bad I decided to go ahead and rebuild both before getting the machine hot to check the charge pressure. The rebuild went well, but afterwards the blade would constantly fall. I was afraid I may have messed something up in the rebuild. It had never done that before. The only reason I rebuilt them was because they were dripping bad.

I was hoping it was just air in the lines, but I ran the machine for approx 15-20 min. I cycled them up/down repeatedly with no change. You can watch the blade drop. I'd guess it drops an inch every 10 seconds or so.

So today I was able to get some caps to test the cylinder. I set the blade on a wood block approx 6" high, then capped both sides of both lift cylinders. I rolled the machine back off the wood block and the blade doesn't drop at all. It's been in the air for the last 30 min or so. So what would you recommend I do next? Is it the spool valve leaking by? Or is there a relief somewhere that could be stuck open? Is it possible there is air in the system still? The linkage from the joystick feels good, and I don't think it's putting any pressure on the spool valve while in the neutral position.

Thanks!!
 

GaryHoff

Senior Member
Joined
Feb 25, 2009
Messages
810
Location
Alberta, Canada
Occupation
Heavey Equipment Mechanic
Capping off both ends of the cylinder has limited test results for cylinder internal leakage. My first thoughts are that a seal has gotten pinched upon re-assembly of the cylinders. Its not very likely to have a valve issue immediately after a cylinder rebuild. The quickest check for you is to probably disassembled them again, as you only need to look at the piston seals on the rod.
If you would like to do a actual cylinder leakage test, to determine which cylinder may be at fault perform the following steps.
1. Lower the blade, and relieve all pressure on the blade.
2. Remove the pins on the rod end of both cylinders.
3. Fully retract the cylinders.
4. Remove the barrel end hose on both cylinders, and cap the hose. Leave the fitting on the cylinder open.
5. Start the machine and try to retract the cylinders. If the cylinder is leaking internally there will be a steady flow of oil coming out of the barrel end fitting
 
Last edited:

mleto1

Member
Joined
Mar 4, 2016
Messages
23
Location
Louisiana
Gary,

I did the test and only had a handful of drips come out of the left cylinder. I believe that was due to that cylinder being propped up a bit. Once I lowered the opposite end of cylinder there were no more drips. There was definitely not a steady flow to speak of. I even tried revving the machine up a bit, but had no oil coming out.

Any thoughts? Is there any chance there is air in the system? Or a relief valve stuck open? You can hear the machine bogg when you hit the end of travel of the lift cylinders in either direction, which feels normal.

If I have the blade lifted all the way up, and drop it fast when it hits the ground it "bounces" for a second. And takes a second before it lifts the front of machine up. Which feels like a massive air pocket, but I really have no idea. The cylinders still feel very strong. And machine feels strong in general.

Any help would be greatly appreciated!

Thanks!
 

GaryHoff

Senior Member
Joined
Feb 25, 2009
Messages
810
Location
Alberta, Canada
Occupation
Heavey Equipment Mechanic
It would seem that the cylinder leakage is minimal, and should not be your cause of drifting.
Air in the cylinders should have worked out with a few lifting and lower cycles.
To determine if your valve is the issue, switch the hoses from the lift circuit to the tilt or ripper circuit. Then re-test.
 

mleto1

Member
Joined
Mar 4, 2016
Messages
23
Location
Louisiana
I do not have a ripper, and it appears the other 2 circuits have different sized connections than the lift cylinders. Any other way to test? I can take some pictures if you'd like.

Thanks,
Jay
 

mleto1

Member
Joined
Mar 4, 2016
Messages
23
Location
Louisiana
I will have to rig up some gauges and fittings to test that. Will I need 2 gauges?

Also, I wanted to add that the whatever is letting the cylinders leak down is doing it in both directions. If I raise the blade it falls while the joystick is in the neutral position. If I raise the blade and push the joystick down the blade "bounces" briefly when hitting the ground, then hesitates for 2 seconds, then lifts the front of machine up. After returning the joystick to neutral the cylinders leak down and the front of machine slowly come back on the ground.
 

GaryHoff

Senior Member
Joined
Feb 25, 2009
Messages
810
Location
Alberta, Canada
Occupation
Heavey Equipment Mechanic
To swap the hoses to another valve section, you will have to also swap the fittings in the valve. The valve sections are all 7/8 orb.
 

mleto1

Member
Joined
Mar 4, 2016
Messages
23
Location
Louisiana
Ok I swapped the lift and tilt hoses at the spool valve. So now I have to move the joystick to the right to lift the blade. As soon as I let off the blade starts to fall again. Just like it did before swapping the hoses.

What do I need to test next? Thanks a ton for all the help!!
 

GaryHoff

Senior Member
Joined
Feb 25, 2009
Messages
810
Location
Alberta, Canada
Occupation
Heavey Equipment Mechanic
I'm assuming the tilt wasn't drifting. I'm also assuming that you had swapped all 4 hoses. (so the lift raise and lower were side to side and the tilt was forward and back on the joystick)

If the valve is good, that means the cylinder is bad. It still seems likely that you have a bad seal in the lift cylinder. If your tilt wasn't drifting before then that section should be good. Its very unlikely that you have 2 bad sections in the valve stack. I would recommend re-testing the lift cylinders for leakage.

1. Lower the blade, and relieve all pressure on the blade.
2. Remove the pins on the rod end of both cylinders.
3. Fully retract the cylinders.
4. Remove the barrel end hose on both cylinders, and cap the hose. Leave the fitting on the cylinder open.
5. Start the machine and try to retract the cylinders. If the cylinder is leaking internally there will be a steady flow of oil coming out of the barrel end fitting

If this still shows no signs of leakage, repeat the test, but with the rod end.

6. re-connect the barrel end hoses.
7. Extend the cylinder all the way out.
8. Remove the rod end hose, and plug the hose. Leave the fitting on the cylinder open.
9. Start the machine and try to extend the cylinders. If the cylinder is leaking internally, then there should be a steady flow of oil coming from the rod end fitting.
 

mleto1

Member
Joined
Mar 4, 2016
Messages
23
Location
Louisiana
Correct the tilt was not drifting before. I'll check test the cylinders, and will be back in touch. It will likely be a couple days.

Thanks!
 
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