Case 580c Steering mystery

[raven1989]

Well I have read every forum thread known to mankind and still cannot sort this mystery out. I have a case 580c hoe with steering issues. Power steering rarely works. When it does, it works great but rarely does it work. When front bucket is empty steering works to some degree (can spin steering wheel and get wheels to turn) but as soon as I scoop up something forget it. I lose any power steering assist (steering wheel cannot be turned). I have replaced the pump, both steering cylinders, filter, all new fluid, steering body (on the steering shaft below steering wheel) with all newly purchased items... not used parts! Since it does work on occasion, it seems the parts actually do work when they work. I was thinking a valve ball stuck somewhere that frees itself up on occasion, but after replacing all parts with new parts nothing has changed. What the heck is left in that system that could be at fault? I suppose maybe I got a bad pump. I do not have a way to check for pressure out of the pump. Any thoughts guys and gals?

 

[Truck Shop]

Any difference hot or cold? Can't check pressure at cylinders? Suction side partially blocked?

 

[Mike4799]

"Suspension" components so worn they are bound up with the weight of a full bucket on them?

 

[raven1989]

Thanks for the reply.. Does not seem to matter hot or cold. I do not have a gauge and fittings to check pressures. May be a good investment. When I crack a hose at a steering cylinder it will bleed fluid when idling so there is some pressure. I have not tried having someone operate the steering while I crack a line to see if rate of fluid escaping increases. Forgot to mention I lifted wheels and turned wheels all the way right to left several times to bleed system when installed pump and cylinders.

 

[raven1989]

Hi Mike. I can free wheel the wheels back and forth by hand when wheels are off the ground by grabbing a tire and pulling so I figured that was a good sign and nothing bound up.

 

[RZucker]

Do you have a priority flow divider somewhere in the system? I would have never touched the other parts before a gauge test... but that's just me.

 

[raven1989]

Yeah.. Lesson learned. I replaced the pump first and when that did not help I slowly just replaced each piece one by one. As for priority flow diverter. Thats a good question. How would I find that out?

 

[RZucker]

Yeah.. Lesson learned. I replaced the pump first and when that did not help I slowly just replaced each piece one by one. As for priority flow diverter. Thats a good question. How would I find that out?

You have a schematic? if it does use the flow divider, that is your pressure supply and the relief valve for the steering. Follow the pressure/input line from the steering wheel pump back to the source.

 

[raven1989]

I do not have a schematic. Will chase those lines and see what I find. Thanks for the input

 

[Tinkerer]

Have You done anything with the steering valve ? It is located on the bottom of the steering shaft. It has steel hydraulic lines on it.

 

[RZucker]

Have You done anything with the steering valve ? It is located on the bottom of the steering shaft. It has steel hydraulic lines on it.

Pretty much has to be it. I found a schematic online and didn't realize the 580C had a dedicated steering system with a separate pump.

 

[Truck Shop]

It says above he replaced a steering body at the base of the column. He probably meant valve I suppose. Seems he is running out of fluid. IMO Does the steering pump make any noise when turning?

 

[alrman]

You will have to check the relief pressure. If there is not enough pressure, it won't perform as it should.
It should operate at 2000 +/- 100 psi at full RPM

 

[Tinkerer]

Any progress, raven ? Although you installed a new pump, did you check the filter in it for contamination ? Maybe this will help. Carefully check that you have the lines in the correct order.

 

[raven1989]

Hi y'all.. Thanks for all the input. I forgot to mention if I get the revs up around 2000 I do get some steering (usually) with a load in the bucket. I followed lines and did not see anything weird there. All lines are in correct locations. I was able to use it today and make some wide turns (having independent brakes helps in a pinch) but still stumped. I seriously need to get test equipment so I can check pressures I guess. Its like night and day when it works. When it stops I cannot turn the steering wheel at all. If I am moving and trying sometimes I can slowly get the steering wheel to turn but wheels do not respond. Sure does seem like a pressure issue.

 

[raven1989]

Does anyone know if the relief valve is internal in this pump.

 

[Bls repair]

Pick up wheels any play in king pins?

 

[raven1989]

No..One of the first things I checked. Front end seems tight and smooth.

 

[JD955SC]

Any progress, raven ? Although you installed a new pump, did you check the filter in it for contamination ? Maybe this will help. Carefully check that you have the lines in the correct order.

View attachment 196731

I wish the hydraulic diagrams I have to deal with were that clear and easy to follow.

 

[Tinkerer]

My research came up with this.-----> Relief valve pressure check:
1. Disconnect outlet(top)hose from the steering pump.
2. Install a 0-3000 pressure gauge with swivel tee between hose & pump fitting.
3. Start engine & run at full throttle. Turn wheels all the way to the right or left & observe pressure gauge.
4. If pressure was not as specified(2000+/-100psi)the relief valve must be replaced. The valve is nonadjustable & non-repairable. The relief valve is in the steering pump.
The relief valve is #17 on the far LH side in the schematic.