Friday, December 9, 2011

How to Replace Head Gasket on Toyota Previa ?

Its not Easy procedure,its time consuming procedure.All proper tools and Auto Repair Basic experience is required.The details are as follows
The engine and transmission has to be removed together as a complete assembly to access the head gasket.
This is done by lowering the engine and transmission from under the vehicle. You will have to lift the van up on a hoist to accomplish this.
You can also do it without removing engine,but that is very less room/contested procedure.
you do need to undo the two main engine mounts and lower the engine slightly using a trolley jack under the sump. This is to enable you to get to the inlet manifold bolts that are hidden under the fixed section of floor between the front seats.
Turn the engine off,let it cool down,then lift the van up.disconnect battery negative cable for safety reasons.
Drain the coolant before doing this job.Drain coolant from radiator drain plug.You can collect coolant in pan.
Use your wrench to remove the mounting bolts from the air filter unit, alternator and exhaust manifold. Lift them all from the vehicle keep it aside.
Now remove radiator hoses and cooling line carefully,without breaking/cracking any thing.Remove the mounting bolts attached to the timing belt cover and lift it from the engine. This will give you access to the head gasket.
Remove the bolts attached to the cylinder head, starting at the far left-hand side and working your way around in a cross-hatch pattern. Lift the cylinder head off the engine block and move to one side. Remove the damaged head gasket.

Also without forget go through this list also,for better understanding on replacing Head gasket:----

How to Remove Exhaust Manifold on Toyota Previa?

How to Remove Intake Manifold on Toyota Previa?

How to Remove Timing Chain Cover and Seal on Toyota Previa?

How to Remove Timing Chain and Gears on Toyota Previa?

How to Remove Cylinder Head on Toyota Previa?

How to Remove Engine on Toyota Previa?

How to Remove Water Pump on Toyota Previa?