Case 310B Power Steering Pump

This particular tractor has the gear driven power steering pump. If the cylinder is not the problem, I'm wondering if what can be done to the pump. I thought that I'd seen somewhere that the gear pump cannot be rebuilt/serviced. Anyone experienced problems with one of these and been able to solve it? Common problems to look for? The pump has been losing oil, but I think part of that problem is in the cylinder. Any help/ideas appreciated!

It's a safety feature so when you shut off the engine the pump stops and there is a hydraulic lock to prevent the loader from dropping if someone were to accidently bump the loader control valve lever(s).

So you may want to check that the pump is actually running and delivering some pressure.

Check the oil level in the torque tube. Check the pump lock-out plunger is fully engaged.

Joe

The pump can be taken apart, but I am not sure what could be done if it is not making enough pressure. There are two gears and a plate that may be worn badly enough that the pressure is low. Have you tested the pressure? If the plate is badly worn where the gears contact it, a good machinist could probably build you another one. It may be easier to look around for another pump to pull the gears & plate out of. There is a big O-ring between the can and the pump itself that can allow oil to leak past. But you'd notice that easy enough if it was leaking.

What are the part numbers of those kits you found? I would like to get those myself.

Another way to get more turning power is to lenghten the arm at the left spindle. You'd be suprised at how much it helps for that arm to be longer. You lose a bit of turning radius and the guard will need to be modified, but the trade off is worth it. A previous owner did a po' boy job on mine that looks horrible. I scrounged up a proper steering arm and replaced the butchered but longer one. It only took using the tractor one time to go back to the longer arm.

G45077 Kit-valve seals
G45078 Kit-ball stud
G45079 Kit-cylinder seals (broken into component parts)

G45077 was available from my CaseIH dealer, the other two were not available from the CaseIH dealer, but were available through a Case construction equipment dealer a little further away. From what he told me, I may have gotten the last G45078 kit, which he obtained through a dealer search. The component parts may be available (2 of G46110, 1 of G46112 & 1 of G46114). G45079 is no longer available as a kit, but the component parts are listed under the former number and are available. Can't tell you the price because I didn't ask when ordering and I haven't picked them up. Apparently one of the parts is on backorder to the warehouse. If I find out more, I'll let you know.

This spring has been trying for this tractor. The left hand spindle snapped at the edge of the hub while carrying a load. My Dad's lucky he didn't get hurt--but he'd known the spindle was weak. Earlier this spring the drag arm (the one you're holding in the picture) snapped and we had a local shop repair it (so far it has held). All of this is probably the result of a worn front axle. The axle had started to split where the spindle rotated. After a new axle and spindles are installed, power steering cylinder redone, she'll be like a new machine!

I'll get back to you on the kit numbers. Don't have them with me right now.

The relief valve is the slot head plug located under the return line fitting. Remove the plug, shims, spring with ball on the end. Some oil should leak out washing the seat area. Clean the seat area with ATF in a pump type oil can if necessary. If the ball and spring look ok, reinstall with same shims.

If the steering cylinder is not functional, you can check pump pressure by making up a recirc line. Add a valve and tee with a pressure gauge. The pump housing inlet/outlet is threaded 3/8" npt.

Run the engine full no load rpm, slowly close down the valve, pump should put out 950-1050 psi before the relief opens. Don't close the valve all the way for more than a few seconds with the pump running. Pump oil should be warm for accurate reading.

If you don't get full pressure, add some flat washers to the relief valve to prevent it from opening and try the test again.

Joe

I have not done a pressure test on mine, but did add shims to the point of almost not being able to get the ball/spring back in place. Is there any other way to increase the pressure short of replacing the gears? The additional leveralge of the longer arm helped quite a bit.

Mike Johnston

After you pull the reservoir off, the pump body is clamped with 8 machine screws. Immediately under the screw heads is the pump suction plate. The plate will be distorted around the screws and won't seal again metal to metal. Put a gasket & sealer there.

The pump body mating surfaces are metal to metal. Use a sealer that is intended for that purpose, permatex #2 is not going to cut it.

Before lifting out the pump gears mark them for reassembly in the same tooth-tooth mesh. Oil is pumped up between the gear teeth so there will be less wear (spalling) on the non-pumping side of the teeth. You can turn them both over for a better surface.

The drive pumping gear has a keyway that fits over woodruff key in the shaft. Check the woodruff key for wear, especially a score mark along the shear line. Check gear fit to shaft if key wear. I renew the key in this type pump even if it looks new.

There is plenty of meat to machine out light scoring on the gear ends and matching surfaces of the pump body.

The bearings are needle type. You can't see wear until it is advanced and it shows up as a shadow on the needles. Pack the needles together in the cage, the gap width should be more than one but less than two needle widths. A full cage is 24 needles.

The relief ball on the ones I've seen are secured to the spring. If the ball is marked up you might want to try tinning it with lead solder or replacing with a ball bearing. I haven't had any problem with these so haven't though much about it.

I think I would get a pressure test on the pump before doing anything. Pushing a direct connected cylinder is slower than the torque provided by a Char-lynn that is already rotating at full speed. More over-all force, just slower?

Joe

Mike