Pump Flow and Pressure Test
Pump Flow and Pressure TestWARNING: Do not touch the flowmeter during the test procedure or severe burns and serious injury can occur. Failure to follow these instructions may result in personal injury.
1. CAUTION: Make sure that the connection point does not interfere with any of the engine accessory drive components or drive belts.
Install the power steering analyzer at the high pressure port of the power steering pump. Make sure the power steering analyzer gate valve is fully open.
2. Place a dial thermometer in the power steering pump reservoir.
3. Check the power steering fluid level. If necessary, add the specified power steering fluid.
4. Install a digital tachometer.
5. CAUTION: Do not hold the steering wheel against the stops for more than 3 to 5 seconds at a time. Damage to the power steering pump can occur.
Start the engine. Place the transmission in NEUTRAL. Set the parking brake. Raise the power steering fluid temperature to 74 - 80 degrees C (165 - 175 degrees F) by rotating the steering wheel fully to the left and right several times.
6. With the steering wheel in the straight-ahead position, set the engine speed to 2,100 rpm. Record the flow rate and pressure readings.
^ If the pressure reading is greater than the pressure specification, check the power steering hoses for kinks and restrictions.
7. Partially close the gate valve to obtain 5,171 kPa (750 psi). Set the engine speed at idle. Record the flow rate.
^ If the flow is less than the specified flow rate at idle, install a new power steering pump.
8. CAUTION: Do not allow the gate valve to remain closed for more than 5 seconds.
Completely close and partially open the gate valve 3 times. Record the pressure relief valve actuation pressure reading.
^ If the pressure does not meet the relief pressure specification, install a new power steering pump.
9. With the steering wheel in the straight-ahead position and the gate valve fully open, set the engine to 2,100 rpm. Record the flow rate.
^ If the flow rate is less than the specified flow rate at 2,100 rpm, install a new power steering pump.
10. CAUTION: Do not hold the steering wheel against the stops for more than 3 to 5 seconds at a time. Damage to the power steering pump can occur.
Set the engine speed at idle. Turn (or have an assistant turn) the steering wheel to the left and right stops. Record the flow rate and pressure readings at the stops.
^ The pressure reading at both stops should be nearly the same as the maximum pump relief pressure.
^ The flow rate should drop to less than 1.9 liters/minute (0.5 gallons/minute).
^ If the pressure does not reach the maximum pump relief pressure or the flow rate does not drop to less than the specified value, excessive internal leakage is occurring. Install a new steering gear as necessary.
11. Turn (or have an assistant turn) the steering wheel slightly in both directions and release quickly while watching the pressure gauge.
^ The pressure reading should move from the normal back pressure reading and snap back as the steering wheel is released.
^ If the pressure returns slowly or sticks, the rotary valve in the steering gear is sticking or the steering column is binding. Check the steering column and linkages before repairing the steering gear.