Tractor Repair: tractor repair, flow divider, spring tension

Question
474 international tractor ser#2310040B101776-X- complaint of weak power steering at lower rpm's. can a larger hydraulic pump be installed to increase steering performance or can the flow divider be adjusted or modified to increase steering performance and how is either mod accomplished. thanks for your time .

Answer
  No, I don't think a larger pump can be installed.  Even if it could, the flow divider only allows 3 gallons per minute to the steering no matter how big the pump is, and a larger pump would not change the pressure.  The flow divider is set by spring tension and also has an orifice to meter enough oil to the steering before allowing oil to other functions so that the steering will have priority.  It is not adjustable and I would not recommend modifying it because it might adversely affect the operation of the entire hydraulic system.  If the filter is clean and the pump is good, then the steering relief valve and flow divider spring and orifice should be checked.  The only way to know if the pump is good is to hook it up to a flow rater and test it or remove and disassemble it to see if it's worn out.  Just checking a pump with a pressure gauge does not accurately test the pump.  A worn pump can still produce enough pressure, but won't have enough flow under pressure.  A flow rater will show how much flow there is with no pressure compared to the flow at maximum pressure.  There should not be more than 10% difference between the flow at no pressure, and the flow at maximum pressure.  If there is more than a 10% loss of flow under pressure, the pump is worn out or there is an internal leak in the hydraulic system.