How To Replace Cylinder Head on Toyota Prius?

Toyota Prius Cylinder head removal procedure.
How to replace cylinder head details and diagram are mentioned here.


Cylinder Head
REMOVAL & INSTALLATION Procedure is as follows:---

1. Properly relieve the fuel system pressure.
2. Drain engine oil.
3. Drain transaxle and engine coolant.
4. Disconnect the negative battery cable. Wait at least 90 seconds after disconnecting the negative battery cable to prevent possible airbag and seat belt pretensioner activation.
5. While wearing insulating gloves, slide up the lever of the service plug grip and remove while turning the lever to the left. Be sure to insulate the service plug with insulating tape.
   
   CAUTION

   Do not touch the high voltage connectors and terminals for 5 minutes after removing the service plug grip.
6. Remove the 2 bolts and 2 compression rings, then disconnect the exhaust pipe assembly front from the exhaust manifold.
7. On 2002-03 Prius models, while wearing insulating gloves, remove the converter and inverter assembly as follows:
   
   
   
   
   1. Disconnect the battery power cable connector and insulate it with packaging tape.
   2. Remove the inverter terminal cover.
   3. Disconnect the circuit breaker sensor by first moving the outer cover section away toward the wire side.
   4. Remove the circuit breaker sensor.
   5. Verify that there is 0V by measuring the voltage between the terminals of the three phase connector (U-V, V-W, U-W), using a voltmeter at each terminal and body ground.
   6. Remove the mounting bolts and disconnect the MG1 and MG2 power cables. Protect the connector parts with insulating tape.
   7. Disconnect the ground cable.
   8. Disconnect the 3 water hoses from the converter and inverter assembly.
   9. Remove the 4 mounting bolts and the converter and inverter assembly.
8. On 2004-06 Prius models, while wearing insulating gloves, remove the inverter with converter assembly as follows: 
   
   
   
   
   1. Remove the left and right engine under covers.
   2. Drain the HV coolant.
   3. Remove the radiator support opening cover.
   4. Remove the inverter cover.
   5. Verify that there is 0V at the inverter with converter, using a voltmeter utilizing a measuring range of DC 400V or more. 
      
      
      
      Fig. Verifying that there is 0V at the inverter with converter-Prius
   6. Again, verify that there is 0V by measuring the voltage between the terminals of the three phase connector (U-V, V-W, U-W), using a voltmeter utilizing a measuring range of DC 400V or more. 
      
      
      
      Fig. Measuring voltage between the terminals of the three phase connector-Prius
   7. Disconnect the No. 1, No. 2 and No. 6 inverter cooling hoses.
   8. Disconnect the No. 1 circuit breaker sensor by first moving the outer section away toward the wire side.
   9. Disconnect the 2 frame wire connectors from the inverter with converter assembly and protect the electrode and connector parts with insulating tape.
   10. Use a small screwdriver to lift up the green lock pin, then disconnect the connector for the air conditioning inverter.
   11. Disconnect any remaining wiring connectors including the engine main wiring harness.
   12. Remove the mounting bolts and disconnect the MG1 and MG2 power cables. Protect the connector parts with insulating tape.
   13. Remove the 3 mounting bolts and the inverter with converter assembly.
9. Remove timing chain.
10. Disconnect associated connectors and wire harnesses.
11. Remove the fuel pipe clamp.
12. Disconnect the fuel tube from the fuel delivery pipe. Even if the fuel tube is stuck and cannot be disconnected, do not use any tools. Push and pull the parts with the quick connector pinched to disconnect the tube.
13. Cover the disconnected fuel tube and fuel delivery pipe with a plastic bag in order to prevent foreign objects from entering them.
14. Disconnect the radiator inlet hose from the cylinder head.
15. Disconnect the hoses from the cylinder head as shown in the illustration.
16. Remove the bolt and disconnect the No. 1 water by-pass pipe.
17. Disconnect the hoses, remove the bolt and disconnect the oil dipstick guide.
18. Remove the camshafts. 
    
    
    
    Fig. Cylinder head bolt loosening sequence-1.5L hybrid engine
19. Using an 8mm bi-hexagon wrench, loosen the cylinder head bolts in several steps in the proper sequence. Then remove the cylinder head bolts and washer.
    
    CAUTION

    When removing the bolt, do not drop the washer into the engine. Removing the cylinder head bolts in the wrong order may cause damage to the cylinder head.
20. Remove the cylinder head and gasket.

To install:

Fig. Seal packing correctly applied for cylinder head installation-1.5L hybrid engine

1. Install the cylinder head along with a new gasket.
2. Apply seal packing with a 0.177-0.217 inch (4.5-5.5mm) thickness. Install the cylinder head within 3 minutes of applying seal packing.
3. Apply a light coat of engine oil to the threads of the cylinder head bolts.
   
   
   

   

   Fig. Cylinder head bolt tightening sequence-1.5L hybrid engine
   
   
   
   

   

   Fig. Retightening the cylinder head bolts by an additional 90 degrees-1.5L hybrid engine
4. Using several steps, install and tighten the 10 cylinder head bolts and plate washers uniformly with an 8mm bi-hexagon wrench in the proper sequence to 21 ft. lbs. (29 Nm).
5. Mark the front of the cylinder head bolt with paint.
6. Retighten the cylinder head bolts by an additional 90 degrees and then another 90 degrees. Check that the paint mark is now 180 degrees opposite to the front.
7. Install the camshafts.
8. Install the oil dipstick guide with the bolt and tighten to 80 inch lbs. (9 Nm). Connect the hose.
9. Connect the water by-pass pipe with the bolt and tighten to 80 inch lbs. (9 Nm).
10. Connect the hoses.
11. Connect the radiator inlet hose.
12. Push the fuel main tube into the fuel delivery pipe until it makes a "click" sound. If the fuel tube is connected too tightly, apply a light coat of engine oil to the tip of the fuel delivery pipe. After connecting, check that the fuel tube is securely connected by pulling it.
13. Install the fuel pipe clamp.
14. Connect all associated connectors and wire harnesses.
15. Install the timing chain.
16. On 2002-03 Prius models, while wearing insulating gloves, install the converter and inverter assembly as follows:
    
    
    
    
    1. Install the converter and inverter assembly and torque the 4 mounting bolts to 15 ft. lbs. (21 Nm).
    2. Connect the 3 water hoses to the converter and inverter assembly.
    3. Connect any remaining wiring connectors.
    4. Connect the ground cable.
    5. Connect the MG1 power cable and 3 mounting bolts. Torque the 3 mounting bolts to 62 inch lbs. (7 Nm).
    6. Connect the 3 MG2 power cables and 6 mounting bolts. Torque the Amounting bolts to 14 ft. lbs. (19.5 Nm), and the B mounting bolts to 71 inch lbs. (8 Nm). 
       
       
       

       

       Fig. MG2 power cables and mounting bolts-2002-03 Prius
    7. Install the circuit breaker sensor and connector cover. Torque the 2 mounting screws to 15 ft. lbs. (20 Nm).
    8. Connect the circuit breaker sensor.
    9. Install the inverter terminal cover and gasket. Tighten the 4 screws to 71 inch lbs. (8 Nm).
17. On 2004-06 Prius models, while wearing insulating gloves, install the inverter with converter assembly as follows:
    
    
    
    
    1. Install the inverter with converter assembly and tighten the three mounting bolts to 16 ft. lbs. (21 Nm).
    2. Connect the MG1 and MG2 power cables and tighten the mounting bolts to 71 inch lbs. (8 Nm).
    3. Connect any remaining wiring connectors including the engine main wiring harness. Be sure to insert the grommet of the engine main wiring harness into the U-shaped groove of the inverter case.
    4. Engage the connector for the air conditioning inverter and secure by pushing in the lock pin..
    5. Connect the 2 frame wire connectors to the inverter with converter assembly.
    6. Connect the No. 1 circuit breaker sensor.
    7. Connect the No. 6, No. 2 and No. 1 inverter cooling hoses.
    8. Install the inverter cover and tighten the mounting fasteners to 8 ft. lbs. (11 Nm).
    9. Install the radiator support opening cover.
    10. Install the left and right engine under covers.
18. Install the front exhaust assembly.
19. While wearing insulating gloves, joint the service plug grip with the HV battery. While pushing the service plug grip to the right, rotate the lever to the right. Slide the lever down to lock the service plug grip in place.
20. Connect the negative battery cable.
21. Refill engine oil.
22. Refill transaxle and engine coolant.
23. Start the engine and check for leaks, check for abnormal noises, shock slippage, correct shift points and smooth operation.
24. Recheck transaxle and engine coolant.
25. Perform system initialization (2004-06 models).

These details will help.

Thanks.

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Car repair guide?

http://technoanswers.blogspot.in/2012/03/car-repair-guide.html