Ford F3ZZ-6571-C Valve Stem Seal

Some of the damages such as broken valve springs and faulty valve stem seals can be fixed without having to remove the cylinder head; this can only be done with two special tools and a source of compressed air. If there is no compressed air at the workers' disposal, it is possible to employ a piece of nylon string in order to stop the valves to fall into the cylinder. Starts with the cylinder head and spark plug of the particular cylinder being procured and by then rotate the crankshaft in order to align the piston at the TDC of the compression stroke. An adapter should be screwed in the spark plug hole to attach an air hose to a compressed air unit. Unbolt the mounting nut or bolt, dismantle the rocker arm/fulcrum and take out the pushrod for the defected valve and while doing this, blow compressed air into the cylinder. In case of the nylon rope, you should place the piston around forty-five degrees before the TDC, and then you introduce the rope into the combustion chamber and then turn the crankshaft until some level of resistance is experienced. Coat steel shop rags and fit them over the oil return holes, then compress the valve spring with the help of a valve spring compressor and unscrew the keepers to set away the spring retainer together with the valve spring. Remove the old valve stem seal while checking that you have the spring shim in place before you replace the valve stem seal. Place the valve stem under tape or rubber band to add stability to the valve stem and check for any kind of damage on it. Applying pressure into the air to keep the valve closed before undoing the use of tape or rubber band. Coat the new valve stem seal with the grease and then fit the valve stem seal to it, then the valve spring and retainer must also be fitted. Reduce the assembly and fit the keepers flush with the surface. Remove the air hose and the adapter, then place back the rocker arm and the pushrod. Do the same for all the valve assemblies if replacing all seals and ensure that the piston is at the Top Dead Centre before releasing the valve keepers. Last of all put the spark plug(s) back and reconnect the wire(s) put back the valve cover and start the engine, to check for oil leaks or abnormal sounds.

Yes, the alternative method uses a more commonly available tool but requires the removal of the cylinder head.

Reapply air pressure to the cylinder, then remove the tape or rubber band from the valve stem.

No, the intake and exhaust valve seals on the 7.5L engine are different and are not interchangeable.