So we have a 2004 GMC Sierra 2500HD with the LB7 in it. Two months ago the injectors went out. Didnt have the money for new ones. So we ordered re mans. Installed them at home. After starting it back up some fuel lines were leaking. After some tweaking, we got it to quit leaking. But now its leaking Antifreeze and is smoking bad. Its thick white smoke. Its not leaking oil. It runs really good. We drove it about 200 miles home. (it broke down out of town)
Along the way the low coolant light came on. It was low about half a gallon. Topped it off and brought it on home.
When the injectors were done the cups stayed in and never unseated. So we didnt mess with them. My local mechanic is saying we need to take it apart and replace the cups and seals. Just wondering what every one else has done.
It starts fine, runs good. All gauges look good. Other then the white smoke and leak were lost This is our first diesel. Weve had it less then six months. Its got 205 thousand miles on it.

 

Losing coolant after an injector change is historically a injector cup issue. Never worked on a dmax, however all the Cummins and Navistars I have wrenched on lead me to believe what I stated. Also be advised that most injector cups need to be pressed in and out. This is far beyond a do it your selfer.