Do not use a screwdriver punched into the side of the filter,
as this practice can damage the scavenging tube and screen.
Check the filter to make sure that the threaded nipple did not
unscrew with the filter. If it is in the filter, remove it carefully
to avoid thread damage, coat the threads that go into
manifold block with a small amount of Loctite blue and install
it into the manifold block.
2.11.1 Check the gasket-sealing surface of the manifold block for
contamination, old gasket material or damage.