Being new to diesel engines, maybe I'm just being to cautious. I have a 2004 36FDDS with a 2003 ISL 400 Cummins engine. The manual calls for TMC RS 329 or 330 coolant, either ethylene or propylene glycol. The coolant in the system is green, which I think is ethylene glycol. The coolant I bought today confirms to the TMC RP 229 spec., but is red in color. My question is, are they compatible? Another question, how often should the SCA be checked? The local parts house wouldn't sell me the test strips because he said they were way out of date and they couldn't back their reliability, so that means a 40 mile round trip to get some.
for being so long winded.