Need info on the banjo bolt on top of the secondary fuel filter
. It's on a Perkins
4-107. The banjo is connected to the return fuel
line from the injectors and the return line to the tank. The bolt has a hole up through the center but no apparent hole across the bolt under the bolt head
as most banjo bolts have. Also, the bolt is only 3/4" long (10 mm dia) and only catches 2 threads. It appears to have been replaced at some time. I would think there would be be a cross hole under the head
connecting the center hole from the filter to the return to the tank. Thoughts appreciated. I'm suspecting this is a source of a persistent air leak to the IP.