2002 case 85xt . Running great, shut off , came back and now it will not move or hyd loader functions won’t work. All three green lights on upper right hand display. Park brake light stuck on and hyd charge light is on as well. Previous owner brought it to a local equipment repair shop and they diagnosed as bad hyd pump coupler. I picked it up, had to winch onto my trailer obviously , got home started machine and loader functions worked. Shut machine off, restarted and now nothing works again. I tested power at the neutral solenoid ( I’m assuming I don’t have a service manual yet , and when I press the park brake button it the solenoid works. Wiggles all harnesses and cleaned and moved around relays and nothing changed . I don’t believe the hyd coupler is bad since the loader functions worked when I got it home . Any ideas ? Thanks
I am going to pull the hyd pressure sensor out and test pressure with hyd gauges this evening. Does a spool valve or some sort of solenoid control pressure at the charge pressure sensor? another words if the park brake is not releasing etc will it not have hyd pressure?
So it was diagnosed but not repaired? Honestly my first thought is that the coupler assembly is broken in a way that sometimes the pieces grab just enough to run for a bit, then it comes apart again. But you'll soon know if the pumps are spinning
Correct, previous owner who I bought it from chose not to repair . Then I bought machine from him. Have you ever changed a coupler assembly on these machines? What’s easiest way to go about doing so pulling the pumps or the engine ?
On an 1845c, I slide the pumps forward. Not sure on a 85xt.
So I removed the hyd charge pressure sensor , hooked up a pressure gauge and started engine . Got 0 psi on gauge . Removed gauge and started quickly and a very small amount of fluid trickled out . So unless there is a hydraulic flow solenoid or valve that stops pump flow I think it’s looking like the coupler ..
If you just have a broken coupler on a used machine I'd say you are doing pretty good,At this point, I'd pull any skid plates clean dirt out get a good look at everything else and see if you can combo any other repairs into this. Bad oil leaks? hydraulic leaks? I'm sure the quicker job is just to pull the pumps back. This is piggy back one pump on the other right? Please don't say they are side by side! At least drain the hydraulic and pull pumps out. But if this is a machine you are investing a future in, you are really buying insurance if you pull the motor out. Just think, you could totally clean out the radiator and cooler, you could find that rusted hard line in the belly that is only held together by the dirt caked around it. You'll notice the blown out exhaust gasket, ect ect.
I pulled machine apart today. I chose to pull the pump assembly forward instead of pulling engine . Only took about 1 1/2 hours to tear it down . Anyways I found that the coupler bolts that go threw the drive plate to coupler sheared , all 8 of them! I ordered a coupler the other day, thought that they were a rubber coupler but turns out it is metal, and has rubber dampening bushings for each one of the 8 bolts. Is this a uncommon failure?
No, not uncommon. That spline on the adapter hub looks fairly worn, that's a good idea to replace it. How's the input spline at the pump end? TIP - Be sure you are very careful during reassembly of the pumps & hoses. Any grain of dirt or sand that gets into the hydrostatic system, has the potential to destroy it. BE CLEAN, CLEAN, CLEAN!
I did degrease and power wash the area before starting the job . The pump splines show a little wear but not terrible . I’ll probably go ahead and replace the coupler since it is apart . What causes the bolts to snap like that? Looks like they loosened up and wore partially threw and eventually failed completely
Rubber doesn't last forever..... those rubber bushes (#11) had simply worn out & then the bolts were running directly on the coupler. In this situation, there is always a tell tale "knock knock" warning sign, every time you turn the engine off - Most people just don't realize what they are hearing.
So took a better look at the input splines on the pump end . And they were pretty worn, any recommendations where to send the pump to get a new shaft installed?
Sorry, Hopefully someone else may chime in. Try googling for a Sauer Sunstrand or Sauer Danfoss agent in your area.
So update . Got the shaft replaced by local hydraulic shop . New coupler, all back together . Machine was running and working 100% for about a week now . Today I was using it to move some logs , and all the sudden the loader lift is very slow . If I use another function like curl in or out slightly and lift the loader it works faster but not 100%. I tilted the cab looked for obvious hydraulic leaks or a stick etc blocking the valve and found nothing . Any thoughts?
I just came back inside from moving the machine , it sat for about two hours . Started it, bucket lift still very slow almost to the point of it will not go up unless I rev the machine very high . Also I noticed when I went to go forward the right side was delayed for about 2 seconds then it kicked in and it was fine after that.. going to grab some new hyd filters for it tomorrow change those . Hopefully the pump isn’t going bad ...
Also I played around with the aux hydraulics too see if that was sticking ( had a bobcat do that to me once and had same issues) but it did not make a difference
Any thoughts anyone?
When you're trying to move the lift arms does it load the engine down like it's going through the relief? Does it do it going both up and down? Is it only the lift circuit that's acting up or the bucket circuit too? Is your machine equipped with self-leveling hydraulics? The delayed right side drive is probably unrelated to the loader issue. May have just been some air still trapped. I have had the same thing happen in cold weather.
The engine does not load when trying to lift up or down, curl function does not seem to be affected . It only appears to be having problem with the lift up circuit , I curled bucket down, and used the lift down function and it pickup up the front of the machine with no hesitation. I beleive it has a self leveling valve/ hydraulics .
Hmm I'm at a bit of a loss then. I can't think of anything that would let the lift work fine on the down stroke, but prevent the up stroke without loading the engine (bypassing through the relief). My only thought is a malfunctioning relief valve letting fluid through freely but I would think that would apply in both directions. Can you post a video of it?
I’ll try to get a video of it tomorrow , getting home after dark every night and leaving before sunup. I used the float position that day, any chance I could have torn a oring or something in the valve body when I used float?
I got a video but it’s too large to upload. I also changed hydraulic fluid and filters and added the hto additve . No change to operation, and right side drive function seems like it is less responsive then the left side . Also went and tried to pick up a log length piece of wood and it won’t budge it ... I checked the charge pressure and it’s around 350 psi... I don’t have a manual for the machine , what should charge pressure be and where should I check pump pressure ?
I wish I could help more with the hydraulic control valve but I don't know much about them. I don't think using the float function could damage anything but I guess anything's possible. http://files.danfoss.com/documents/11026743.pdf Here's a link to a service manual for the Sauer Dansfoss M46 tandem pump in your machine. It has a troubleshooting section for sluggish control response time that lists several possible causes. Additionally the response time can be deliberately set by orifices in the supply and drain paths for the servo pistons. Could it be possible that the shop reinstalled the wrong orifices? That charge pressure reading sounds ok. Sauer Danfoss specs from 87 to 450 PSI, and Case calls for 360 PSI minimum at full throttle. Is the response delayed or sluggish? As in you move the stick, wait a second or two, and then the machine moves? Or is the one side just slower to get up to speed than the other?
The response time is delayed at first , wait a second maybe two and it kicks in . Then when it’s engaged it seems like the right side may be a little lazier then the left side when pushed all the way forward it seems like left side is pulling a little .
So, i took the machine to my local hydraulic shop that installed the new shaft in the pump when i replaced the coupler. It took them 3 1/2 weeks, only to tell me that the pump need to be rebuilt.. They confirmed the charge pressure was in spec, and they also said they flow tested it. Going to pick it up today and ill get a more detailed report of what they found. Any input before i have the pump rebuilt?
Good morning guys.. I need your help.. I've joined this site because this page info helped me on my 85 XT with the coupler from the hydraulic pump system to flywheel.. Anyways.. Fixed the broken bolts and bushing in the flywheel housing... all fixed however .. the lift arms are having a struggle going up and you can hear the motor bogged down going upwards.. also got aeration in the hydraulic system now? was wondering if anyone else ran across this problem.? AND got a rebuilt pump to see if that was that was the problem.. Nope.. Thx for any help.. BCB River Grove IL