[Ebro93]

Has anyone ever done a heater core replacement If so please reply with a step by step or video tutorial would very helpful thanks

 

[Submariner409]

Google something like "cadillac forums 2004 deville heater core replacement".

Today will probably be sort of slow for forum participation.

If you really get stuck and want instant gratification, subscribe the car to the online GM/Cadillac service manuals at www.alldatadiy.com. It's all there, with drawings and procedures.