Posted 7/13/2006 09:18 (#26113 - in reply to #26092) Subject: RE: 7.3 Nav diesel Ford F-350
It is quite common knowledge on forums such as thedieselstop to regularly check the additive level in the coolant. I think Ford has some tech bulletins out on it but it wasn't published in an owner's manual. Some engines could be neglected and run a long time. Others had to have the additive from day 1 or they were short lived.