Case 480E

DVrepairman · Jul 25, 2019

I have a friend with a Case 480E backhoe that suddenly lost power steering. With the engine running the steering wheel turns easily right and left but it doesnt move the
front wheels. If you lift the front wheels off the ground and turn the steering wheel the front wheels barely move.The valve at the bottom of the steering column has 5
lines coming out of it. I assume one is pressure,one is return to tank,one for right ,one for left but Im unsure about the fifth...a drain possibly? Does anyone know a
test proceedure to determine if its this valve or if it has a seperate power steering pump that may have failed? Any help is much appreciated. Thankyou!

AJ. · Jul 25, 2019

No pump, pressure comes from the main hydraulics,the plumbing on the orbital valve is crucial,it is seldom anything goes wrong with the said valve and when it does it is usually a leak,the orbital valve doubles as a pump should the engine cut out going along the road at speed you would still have steering but it would be very heavy,when the wheel spins around and does not move the wheels it is usually an issue in one of the cylinders,if the seal let go in one that is enough for the wheels not to move,put someone in the seat and get them to turn the wheel while you hold your hand on a cylinder hose,you may feel the oil bypassing,those cylinder rods often break,to open the cylinder clean the gland end,you will see a spring clip,remove it,with a suitable drift knock the piece the clip was on into the cylinder an inch,pull the large washer out,look at the side of the barrel you will see a groove with a spring clip,remove the spring clip and you can pull the rod from the cylinder.
AJ

DVrepairman · Jul 25, 2019

Thank you AJ. I will check out the cylinders.

Case 480E

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AJ.

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