2003 2500hd duramax heater core removal

[craig57]

trying to replace heater core can any on tell me if air conditioning lines need to be removed to remove heater core assembly

[j cAT]

Originally Posted by craig57

trying to replace heater core can any on tell me if air conditioning lines need to be removed to remove heater core assembly

the dash must be removed. the evap lines I believe don't need removal. minor issue with that. the dash removal is a big job good luck.

why did this leak ? what coolant is in the system ?

[craig57]

I got most of dash lose already and yes ur right that was quite the job exspecially with the console. weve had the truck two or three years and never needed to add coolant, ive yet to drain rad but all I can tell u at this point it appears to be the green type of anti freeze. The heater core is leaking not sure what caused this. Thank u for the quick response

[j cAT]

Originally Posted by craig57

I got most of dash lose already and yes ur right that was quite the job exspecially with the console. weve had the truck two or three years and never needed to add coolant, ive yet to drain rad but all I can tell u at this point it appears to be the green type of anti freeze. The heater core is leaking not sure what caused this. Thank u for the quick response

gm recommends dexcool. they come with this coolant. this was used because of the materials used in the fabrication of this coolant system. the use of non GM approved dexcool is usually in the long run a very expensive error .

dexcool requires changing every 3-4yrs. the green silicate or compatible coolants require replacing every 2yrs.


once a coolant system has a certain type to change type you must flush out the system completely and then use the 15minute acid flush. also distilled water must be used in these engines or the metal gets destroyed.

post back if the evap lines need removal on this one.

[craig57]

will let you know about ac. antifreeze is actually the original gm probabably never has been changed i tried again today on the dash and still havent got it yet probably have to take it in but cant get appoint till next friday. cant get heater box totaly lose yet either. i think this has me.
any exploded views u can send me that may help me with bolt locations

[craig57]

regarding the ac lines on the heater core removal.
Yes they do need to be removed and hole dash has to come out
I ended up bringing it in to DJ Automotive in chwk bc and he said this was the hardest heater core he has tackled yet.
hope this may answer your question and this will help others

[j cAT]

Originally Posted by craig57

regarding the ac lines on the heater core removal.
Yes they do need to be removed and hole dash has to come out
I ended up bringing it in to DJ Automotive in chwk bc and he said this was the hardest heater core he has tackled yet.
hope this may answer your question and this will help others

thanks for that info.....was not sure about the AC evap lines.

I knew that the dash had to be removed and its a big job.

why did the heater core leak .????????

[craig57]

not sure havent had a chance to compltley talk to tech
proably cause the anti freeze was not changed when it was suppose o be

[j cAT]

Originally Posted by craig57

not sure havent had a chance to compltley talk to tech
proably cause the anti freeze was not changed when it was suppose o be

It would be very helpful if you got the details on this failure.

A very expensive job with the loss of vehicle for a few days so it would help if the failure was revealed to help possibly reduce this .

So you really believe its never been changed ?