Component Tests and General Diagnostics

NOTE: When performing the following test, extreme care must be used. Some system pressures can exceed 1500 psi. Ensure test equipment is in good condition and correctly connected.

Installation of the analyzer at the pump outlet is preferred. If it is difficult to attach the analyzer at the pump, it may be installed at any convenient location between the pump and gear. The following test procedure used in conjunction with power steering analyzer tool No. D79L-33610-A (Rotunda Model 014-207), or equivalent, provides a method for checking the complete power steering system. The power steering analyzer can be used to determine the cause of hard steering and/or lack of assist problems.

Contamination of the power steering system fluid may cause permanent damage to the gauges and instruments incorporated in the analyzer. The analyzer provides readouts for the following:
1. System backpressure.
2. Pump flow.
3. Steering gear internal leakage.
4. Power steering control valve and cylinder internal leakage.

The interpretation of the above readouts will determine which of the following conditions or components are the cause of the problem:
1. Restriction in hoses or fittings.
2. Control valve and cylinder.
3. Sticking gear valve.
4. Insufficient pump cam pack.
5. Sticking relief valve.
6. Binding condition in suspension system.

To perform the power steering system pressure test, proceed as follows:
1. Connect the analyzer into the steering system by removing the pressure fitting from the pump and connecting it to the appropriate adapter of the analyzer.
2. Thread the other adapter of the analyzer into the pump.
3. Connect the analyzer to the adapters, then torque connections to 15 ft lb.
4. Add power steering fluid to pump as necessary, then start engine and run for approximately two minutes with engine at idle.
5. Record the flow, if flow is less than specifications, the power steering pump may require repair.
6. Record the pressure at 170 degrees. If the pressure is above 150 psi, check hoses for restrictions or the steering gear.
7. Partially close the gate valve to build up 740 psi for CII pumps, 620 psi for Saginaw pumps. Record flow in Gallons Per Minute (GPM) at 170 degrees. If the flow drops to a level lower than the value specified, disassemble the pump and replace the cam pack. If the pressure plates are cracked and worn, replace them.

NOTE: Do not allow the valve to remain closed for more than five seconds.

8. Completely close and partially open the gate valve three times. Record the pressure and compare to specifications. If the pressure recorded is lower than the minimum specification, replace the control valve. If the pressure recorded is greater than specified, the flow control valve in the pump should be removed and cleaned or replaced.
9. Increase the engine speed from idle to approximately 1500 RPM. Record the flow in GPM. If the flow varies more than 1 GPM from the flow recorded in Step 5, the flow control valve in the pump should be removed and cleaned or replaced.
10. Turn the steering wheel to the left and right stops. Record the pressure (psi) and flow (GPM) at the stops. The pressure developed at both stops should be nearly the same as the maximum pump output pressure recorded in Step 8. At the same time, the flow should drop below 0.5 GPM. If the pressure does not reach maximum output or the flow does not drop below specified valve, excessive internal leakage is occurring. Remove and disassemble the steering gear and remove the control valve. Repair or replace components as necessary.
11. Turn the steering wheel slightly in both directions and release quickly while watching the pressure gauge. The needle should move from normal backpressure reading and snap back as the wheel is released. If the system is severely contaminated, both gear hoses, control valve, and pump must be completely disassembled and cleaned before reassembly. If problem still exists, check ball joints and steering linkage.