1968 Case 530 DOM 3pt. Dropped/Won't Lift Mower

I"m getting back to diagnosing my 1968 Case 530 Draft-O-Matic problem. I was mowing with my 6ft. mower and noticed it was scalping. I went to raise the mower and the 3pt will not raise the mower.
After previous posting I checked the fluid level and the linkage from the lever to the DOM valve. Both OK.
The loader works normally with no issues.
What else do I need to check ?? Thanks

take a line loose and see if you have pressure flow,,,

I don"t have any good repair manual info in front of me yet. Does 3pt. share hydraulics with my front end loader or are they separate/isolated systems because my loader works great.

Experiencing the same problem on a 430 right now. No pressure at remotes or 3 pt lift housing, but motor changes sound when lift lever is raised or remotes are engaged. Thinking I have a seal or gasket blown in the pump, but any advice is appreciated. Sorry for the thread high jack.

Thanks chris

it could be the piston seal

my Liberty 430 acted up like that earlier this spring on the planter ,.it was low on hydro fluid caused by a leaking hydro line ,fixed the lek and changed the hydro filter ,THEN filled it up with case tech fluid that I have for the 1070,.just could not get any Real working pressure to lift the 3pt arms or the remotes ,,after a few days doing non hydro work the lift would occassionallly raise , but would not cycle up and down , I too could hear the pump tryin to do some thing ..I knew the pump was workin then ,,. the 430 hydraulic problem has very few hits in the CASE Forum archives , so apparently there are few problems with the hydraulics as compared to other case tractors ..perhaps in the Liberty 430 , therewas a airlock someplace in the system that took a while to work thru ..it has lifted round bales and the nh 477haybine every time for over a month now and all seems to be working perfect for NOW .. this info probably is of little help TO YOU , other than you mite have a similar circumstances and can relate ..

Without knowing or seeing your setup, it's not possible to tell if you have a secondary hydraulic pump for your loader. Some of the utility versions had a second pump mounted at the front of the tractor.

That being said, the DOM valve is supplied with oil from the main pump via the valve assemblies under the fuel tank. If you have remote hydraulic couplers (or the loader uses these valves) , the DOM supply port will be on the top of one or two valve assemblies. Follow the supply hose from the DOM valve forward along the right side of the torque tube to find that connection.

If in your shoes, I would locate a hand-held/portable pressure gage and find a way to temporally plumb it into that supply port to check for pressure. That will indicate if your problem is in the pump of valve assemblies under the fuel tank, or if your problem lies in the DOM value.

If I remember correctly you have indicted that you are not seeing a drop in your hydraulic oil level, and a corresponding rise in fluid level in the transmission. If that is true, it potentially rules out the rock shaft piston seal. That would defiantly be the case on the early tractors, but if I remember correctly, Case devised a channel on the late models to plumb hydraulic fluid that got passed that seal back into the torque tube/hydraulic reservoir. Since yours is a 1968 model, it leaves that possibility open.

I would first ensure the hydraulic filter has been replaced and properly re-installed. Then I would check the hydraulic pressure in the line that feeds the DOM valve. Then plumb the pressure gauge into the connection between the DOM valve and the rockshaft piston. If that checks out, I would then pull top plate off of the transmission and inspect/replace the rockshaft piston seal and wiper.

The system is very simple. The issue can only be in pump/valve assembly system under the fuel tank, the DOM valve or the rockshaft piston.

Let us know what you find.

I have seen the internal arm on the rock shaft break. Heavy loads like round bales or using boom pole will do that. First check pressure to 3 point.