If the check valve in the gear pump return elbow stays open or closed, replace the elbow.

NOTE: Check the elbow threads. Do not install an elbow that has straight machine threads in a hole that has a pipe tap thread. A gear pump that has a straight thread will have a 19.0 mm [0.75 in] spotface in the valve area. A gear pump that has a pipe tap thread will have a 16.0 mm [0.63 in] spotface or no spotface.

Remove the drain line.

Remove the check valve elbow.

Install the check valve elbow.

If the check valve elbow has machine threads to the maximum thread depth, turn the elbow out until it is pointed toward the drain line. Tighten the jam nut.

If the check valve has a pipe thread, install the elbow until it is tight and pointed toward the drain line.

Install the drain line.