There are two types of struts--sealed one piece struts and cartridge type struts in which the housing remains while the hydraulic cartridge is replaced only. The easiest way to check struts to see if they require replacement is to check for leaks and to do a rock test to see how much resistance to movement they present. Take a knee and push down on the front and rear bumper. When released, the vehicle should stop bouncing after one bounce. If it continues to bounce or has no resistance to bouncing, the cartridge is weak.
Raise and support the vehicle on jack stands. Remove the front wheels.
Raise the vehicle's hood.
Remove the 10mm bolt holding the caliper brake line to the strut. Remove the bolt holding the ABS sensor wire if so equipped. Remove the three 13mm nuts on the top of the fenderwell holding the strut.
Remove the two large through-bolts at the base of the strut that attach the strut to the spindle. Separate the strut at the base by pushing the spindle and strut apart by hand and remove the strut from the vehicle.
Stand the strut upright on the floor with the lower mounting flange facing outward. Place the spring compressor on the spring and compress it to the point that there is no pressure on the top bearing plate. If the bearing plate will turn freely there is enough compression.
Remove the top nut on the top of the strut rod in the center of the bearing plate. Remove the bearing plate and the spring. Be careful with the spring as it is still under compression.
Reinstall the strut on the spindle and just insert the bolts to hold the strut in place while the cartridge is removed. Remove the large nut holding the cartridge in with the large pliers. When the nut is unscrewed remove the strut and place it upright on the floor.
Lift the cartridge out of the strut housing. It will be oily so have a rag and container ready to catch the oil. Discard the cartridge.
Install the new cartridge and place the strut back onto the spindle to hold it while the large nut on the cartridge is screwed on. Once that is done, remove the strut to install the spring.
Install the spring properly on the strut with the bottom end of the spring in its slot in the spring seat. It is easy to see by the depression on the seat where the end of the spring goes.
Install the bearing plate and the nut to hold the bearing plate in place. Once the nut is on tight release the pressure on the spring and remove the compressor. Install in reverse order of removal.
