We run all Bendix AD-SP's on our company rigs. Except for a few of the new ones that have some other gadget onboard.
Spin on filter, easy to replace spitter valve, and heater element.
Convenience is everything, when it comes to fleet maintenance.
$300!! must be for an AD-9. I was thinking that the AD-SP's were around $250-$275.
I can check at the shop tomorrow. Today is my day off.