Check valves are a common source of vacuum leaks in WPG vacuum
lifters. The location of the check valve may vary depending on the make
or model of the lifter. Begin by removing the hose connected to the
check valve, followed by the associated hose fitting. Each check valve
has an arrow on the side indicating the direction of airflow; note the
arrow to ensure correct reassembly.
Disconnect the check valve from the hose fitting and dispose of the
old valve. Remove any excess thread sealant from the threads to be
reused, wiping outward to prevent sealant from entering the fitting.
Install the new check valve in the same orientation as the original, as
indicated by the airflow arrow. Apply a small bead of thread sealant to
the threads, keeping it away from the first one or two threads to avoid
introducing sealant into the check valve.
Reattach the hose fitting to the check valve. Apply thread sealant to
the opposite end of the check valve using the same method and connect
the remaining fitting. Do not overtighten, as the thread sealant will
provide a secure seal. Trim a small portion from the end of the hose if
necessary to ensure a clean, tight connection, then reconnect the hose
to the hose fitting.