930 case hydraulic problems

[carlrj37]

hi I have a 69-70? case 930 comfort king that I put a loader on using the rear auxiliary quick connect valves. I know the valve has wear in it. my problem is that it is stored out doors and is subject to the weather. some how water gets into the system whether it is from around one of the shifter boots or the top cover. but every few years I have to change the hydraulic oil because it gets so it don't want to lift anymore. I don't use the tractor every day. it sits for months at a time. when the oil gets real milky I have to keep moving the lift valve back and forth to get it to lift all the way up. usually after it's warmed up and cycled through the system about 4-5 times it's ok. I changed the oil yesterday any it does the same. also changed the filter. could it be air bound. or maybe the pump is bad now. I bought a cover to stop this from happening. it uses like 15 gals. it just jitters as it's trying to lift. and the dip stick is foamy. I will try lifting it up and down again today that usually does the trick once I get the good oil in all the cylinders. but I tried quite a few time yesterday. I was just wondering if anyone had any suggestions. thanks.

 

[casecollectorsc]

Have a Case 70 loader on my 1030. I run it overfull on the dipstick to have enough oil when lifting all the way up. Only time it chatters is
when picking a bale from a road ditch with the front of the tractor down hill. Oil runs to the front of the case and the pump pick up starves
for oil.

 

[Brokengun]

A 930 CK uses 17 gal of oil in the rear end. Water in the oil over time will cause hyd problems similar to what you have.

If you have a pressure gauge that goes to at least 2000lbs screw a male coupler onto it and measure the pressure at your outlets and lets see what kind of pressure you have.

 

[John Saeli]

You don't need to run the oil level overfull because your cylinders are 2 way, almost as much oil on 1 side as the other, or positive displacement. You do have them hooked up that way, right?

 

[Adirondack case guy]

Over years of use and as you say, the problem of moisture in the hyd oil, you probably have some nasty crud floating around in your oil. The hyd suction screen is in the rear of the tractor between the bullgears.The brass screen is very fine and can plug up. What you say about working when oil is warm would make some sense, because hot oil flows better threw the screen than cold.
My thoughts are that you are going to have to pull the pto housing off the rear and clean the suction screen. If that becomes the situation, thare are some tricks of the trade that will save you time and agrivation, and distruction of the suction screen.
As Brokengun said, check pressure first.
Loren

 

[carlrj37]

ok I tried working it today. I let it run about 6 hours letting it sit for an hour or 2 before trying it. it seemed to get a little better but no where near like it should. it doesn't even have enough down pressure to lift the front end off the ground one lever works better than the other. right know it's the curl lever that works better. one other time it did this I changed the quick connects around so the lift lever was on the other valve. I might try that next. and I will try and get a pressure reading this week. I did put in another 2 gals of oil also. that didn't help. I hope I don't have to take that whole top off again that was a job last time I fixed the 3 point hitch. I had to repair the rockershaft actuating cylinder.

 

[casecollectorsc]

Yes it's hooked that way, but like I said nose down sometimes won't lift until it levels out. Normally not a problem except picking up in a steep ditch and not being able to get to the other side of the bale because of crop.

 

[Adirondack case guy]

You have to take off the pto housing to get to the suction screen. It comes out with that rear housing.
Loren