Power Steering System Test
^ Tools Required:- J 25323-A Power Steering System Analyzer
- J 5176-D Power Steering Pressure Tester
- J 5421-02 Thermometer
The power steering system can be tested using either a J 5176-D Power Steering Gage or a J 25323-A Power Steering Analyzer. J 25323-A will measure the flow rate along with the pressure. The power steering system test s used to identify and isolate the hydraulic circuit difficulties. Before performing the power steering test, perform following inspection and corrections:
1. The pump reservoir for the proper fluid level.
2. The pump belt for the proper tension.
3. The tires for the correct air pressure.
4. The power steering system, replacing parts as necessary.
^ All tests are made with the engine idling at normal operating temperature.
System Test With J 5176-D
1. Place a container under the steering gear or pump to catch the fluid when disconnecting or connecting the hoses.
2. With the engine off, disconnect the pressure hose at the steering gear or power steering pump. Install J 5176-D to both hoses using an adapter fitting J 5176-20. The gage must be between the shutoff valve and the pump. Open the shutoff valve.
3. Remove the filler cap from the pump reservoir and check the fluid level. Fill the pump reservoir (with power steering fluid) to the Full mark on the dipstick. Start the engine and momentarily hold the steering wheel against the stop. Check the connections at J 5176-D for any leakage.
Important
^ Do not hold the steering wheel against the stop for more than 5 seconds as the pump can be damaged internally.
4. Bleed the system.
5. Insert a thermometer J 5421-02 in the reservoir filler opening. Move the steering wheel from stop to stop several times until the thermometer indicates the hydraulic fluid in the reservoir has reached a temperature of 65 to 77C° (150 to 170F°).
Important
^ To prevent wearing flat spots on the tires, do not turn the steering wheel more than five times without moving the vehicle to change the tire-to-floor contact area.
6. Check the pump fluid level. Add power steering fluid if required. When the engine is at normal operating temperature, the initial pressure reading on the gage (valve open) should be in the 550-860 kPa (80-125 psi) range. If the pressure is more than 1380 kPa (200 psi), check the hoses for restrictions and the poppet valve for proper assembly.
NOTICE: Do not leave valve fully closed for more than 5 seconds. This could damage the pump internally.
7. Open and close the gage valve fully 3 times. Record the highest pressures attained each time.
^ If the pressures recorded are within 345 kPa (50 psi) of the specifications, the pump is functioning normally.
^ If the pressures recorded are high, but each reading repeats the same pressures within 345 kPa (50 psi), the pump is functioning within specifications.
^ If the pressures recorded are high, but do not repeat the same pressures within 345 kPa (50 psi), the flow control valve is sticking. Remove the valve, clean it and remove any burrs using crocus cloth or a fine hone. If the system contains some dirt, flush it. If it is exceptionally dirty, completely disassemble the pump and gear for cleaning and flushing and then reassemble before further use. Flush the power steering system including the reservoir before any further use.
^ If the power steering pressures recorded are constant, but are below 690 kPa (100 psi) of the minimum specifications, replace the flow control valve and re-test. If the pressures are still low, replace the rotating group.
8. If the pump pressures are within specifications, leave the valve open and turn the steering wheel to both stops. Record the highest pressures and compare with the maximum pump pressure recorded. If the maximum pump pressure cannot be established at either one of the stops, the gear is leaking internally and requires disassembly for repair.
9. Turn the engine off. Remove the testing gage and reconnect the pressure hose. Verify that the fluid level is full and make the needed repairs.
10. If the problem still exists, verify that the steering and front suspension are functional.
System Test With J 25323-A
1. Place a container under the steering gear or pump to catch the fluid when disconnecting or connecting the hoses.
2. With the engine off, disconnect the pressure hose at the steering gear or power steering pump. Thread the female adapter into the pressure hose and the male adapter into the gear or pump using adapts, J 29525 Connect J 25323-A analyzer hoses to the adapters.
3. If J 25323-A has never been used, it will be necessary to bleed the power steering system to remove all the air.
4. Add power steering fluid to the reservoir if required.
5. Run the engine at idle speed with the gate valve open and record flow (A) and pressure (B).
^ If the flow is below 7.4 L min. (2 gpm) the pump may need repair, but continue the test.
^ If the pressure is above 1035 kPa (150 psi), check the hoses for restriction and check the steering gear.
6. Partially close the gate valve to establish 4278 kPa (620 psi). Record the flow (C).
^ If the flow (C) drops more than 3.7 L/min. (1 gpm) under flow (A), disassemble the pump and replace the ring, rotor, and vanes. Replace all worn or cracked pressure plates. Replace all O-ring seals when reassembling the pump. Continue the test.
7. Completely close and partially open the gate valve three times. Do not allow the valve to remain closed for more than 5 seconds. Record the "gate closed" pressure (D).
8. Check the pressure specifications. If the pump pressure recorded is 690 kPa (100 psi) lower than the minimum specification listed, replace the flow control valve in the pump. If the pressure recorded is above the maximum specification listed, clean or replace the flow control valve in the pump. If the system is exceptionally dirty, disassemble the steering gear and pump completely for cleaning and flushing and reassembled before further use. Flush the system including the reservoir completely before any further use.
9. Increase the engine speed from idle to about 1500 rpm. Record the flow (E).
^ If flow (E) varies more than 3.7 L/min. (1 gpm) from flow (A), clean or replace the flow control valve.
10. Turn the steering wheel lightly against both stops. Record the pressure and flow (F).
^ Pressures developed at both stops should be nearly the same as the maximum pump output (D). At the same time, the flow should drop below 1.85 L/min. (0.5 gpm).
^ If the pressure does not reach maximum output or the flow does not drop below the specified value, excessive internal leakage is occurring. Remove and disassemble the steering gear and remove the control valve.
11. Turn the steering wheel in both directions and release quickly while watching the pressure gage. The needle should move from the normal pressure reading and snap back as the wheel is being released. If it comes back slowly or sticks, the rotary valve in the steering gear is sticking. Remove, disassemble and clean the rotary valve. If the system contains dirt and foreign material, disassemble the pump and gear and clean both. Flush the system including the reservoir completely before any further use.
12. If the problem still exists, verify that the steering and front suspension are functional.