Troubleshooting the hydraulic power-assisted steering

The scope of work troubleshooting of the hydraulic system include:

1) preparatory operations to be performed before measuring pressure:

- Check the level and condition of the hydraulic oil, top up if necessary (replace) the hydraulic oil and bleed the system;

- Check the tension and condition of the V-ribbed belt;

- Check the power steering pump bracket urpvleniya;

2) Connect the measuring equipment:

- Generator cover paper to protect against oil;

- Connect a pressure gauge 999 5055 between the pump and the discharge hose from the body of the steering mechanism (Fig. 7.27). To connect using fittings 999 5175 and 999 5319: 999 5175 close fitting with the bolt "banjo" and clutch rings 999 5319; Connect the hose from the tap pressure gauge hose to the exhaust casing of the steering mechanism; handle faucet pressure gauge is located along the hose;

- Start the engine;

- Bleed the system; Wait until hydraulic oil and power steering pump are warm up to operating temperature (80 ?� C);

3) Check the high pressure hose:

- Check the high pressure hose for clogging and leaks, clean and replace if necessary;

- Recheck;

4) Check the high-pressure:

- Close the drain cock on the pressure gauge

3, note the value of the pressure; Repeat this measurement twice more; you can not close the valve more than 10 minutes, as it can be damaged the power steering pump. The rated pressure - 0.96 MPa pressure fluctuations should not exceed 0.35 MPa;

- If the rated pressure, connect the high pressure hose to the power steering pump and pump system;

- If the pressure is higher than the nominal pressure fluctuations exceed 0.35 MPa, perform "Checking and cleaning the control valve";

- If the pressure is below the rated pressure fluctuations within 0.35 MPa, the options "Replacing the control valve";

5) Check servobalansa when the steering wheel:

- Start the engine;

- Turn the steering wheel all the way almost to the right;

- Set torque wrench 999 8081 on the nut of the steering wheel; slowly turn the steering wheel shaft of the handle to the right torque wrench and torque remember when the pressure gauge shows 1.2 MPa;

- Turn the steering wheel almost completely to the left and note the value of the torque in the same way as when you turn to the right. Torque value should be in the range of from 2.8 to 4.0 N ?� m, and the difference values when turning right and left should not exceed 0.7 Nm. If the difference exceeds this value, replace the steering;

6) Check the pump pressure:

- Start the engine;

- Turn the steering wheel fully to the left and hold it in this position for 10 seconds, reading the pressure gauge;

- Turn the steering wheel all the way to the right, hold the pressure gauge. Nominal pressure - 0.96 MPa;

7) removal of the measuring equipment:

- Cover the generator to protect the paper from falling oil;

- Remove measuring equipment and fittings, connect the discharge hose to the pump using a new O-ring;

- Fill the tank the power steering oil and bleed the system;

- Set the machine parking brake and start up the engine;

- Several times, turn the steering wheel from lock to lock;

- Check that everything is working normally and there is no oil leakage;

- Check the oil level and top up if necessary. The system of the power steering oil should be used ATF- F, G, Dexron D / E Ford Mercon;

h) inspection and cleaning of the control valve:

- Unscrew and remove the control valve (Fig. 7.28);

- Clean the parts and remove existing damage fine sandpaper (600);

- Install new O-ring, and then put the details of the control valve in place;

- Tighten the control valve to 75 N ?� m;

- Check the condition of the hydraulic oil; If the oil is clean, repeat the test pressure; If the oil is dirty, remove the pump, clean it and replace the oil, then recheck pressure. If the control valve is dirty, you also need to clean the power steering pump;

i) replacement of the control valve:

- Disconnect the exhaust pipe from the power steering pump;

- Replace the control valve;

- Connect the exhaust pipe;

- Top up the hydraulic oil in the system;

- Repeat the test pressure;

- If the measured value is not correct, even after repeated measurement, replace the power steering pump;

a) Replacement of the packing rings of the drive shaft power steering pump:

- Remove the power steering pump;

- Remove the oil seal ring with the drive shaft (Fig. 7.29);

- Check for damage and scuffing on the working surfaces of the drive shaft;

- Install new oil seal ring;

- Install the power steering pump;

- Tighten all connections of tubes;

- Fill the tank the power steering hydraulic oil and bleed the system.