we have lots of 6BT's at work, and almost all the ones I have seen have Fleetguard Coolant filters on them. Would it hurt to do the same to a motor with 221k? we use an additive to the coolant, and when I checked mine tonight, it showed it needed some additive to neutralize the silicates or something like that. Anyways, I think it would actually be benificial, but please chime in and correct me if I am wrong. Thanks a million,
-Chris-
-Chris-