I have a 2003 5.9 HO auto trans with 110k on it. Back in October I had the water pump replaced as it was shot and was leaking all over.

I just changed my oil tonight and noticed that my coolant is now at the "low" line and I need to put a decent amount in to get it back up up the fill line. So...over the course of 3 months and probably 2500 miles it went from the "full" to the "low" line. I park outside and it's winter.....but I don't see any significant leaks or really any leaks at all.

Just not sure what to do to track down the issue.

Also......what are the lines on the drivers side of the tranny. They have rubber hose attached to metal lines and are right next to it. Possibly the lines going to the cooler? And if so is that tranny fluid in them? They seem to have a little fluid around the fitting where the rubber hose meets the metal pipe.

 

311... Most likely when you changed the water pump, all of the air was not purged from the system when you refilled it after the water pump change. Pesky air pockets can sometimes take awhile to burp themselves out.
Top off your system with coolant and with a magic marker put a small line on the overflow tank and see if it goes down again. My bet is that it won't.
The rubber lines are from the transmission and are heading to the radiator for cooling. If they are weeping oil they should be replaced.
Also, if you fill out your vehicle information in the user CP section, it will make it easier for others to assist you.
Welcome aboard to the most informative and helpful site for the Dodge diesels.

 

Thanks for the info and welcome. Been lurking here for a little while but until now have been able to find the info needed!!!

I "assumed" since the dealer did it that would not be an issue.....but I was in a hurry and asked them to get me going ASAP. I was in and out of the dealer in less that 1 hour.....so I was happy. Found the original leak on a Friday afternoon on our way out of town for a 4 day pheasant hunt that was 600 miles away. I had no time to do this one myself.......