If I was to do it again i would make one change to what I done,I would still cut the old one out by cutting the pipes and I would still cut the pipes on a new core BUT, I would take the old pipes out that goes thru the firewall, enlarge the holes where the pipes go thru the firewall, and run the heater hose thru the holes and connect them to the cut off pipes on the new heater core,that way its simpe,easy,and only one connection, wouldnt need the swivel ends on the core at all,would be real easy to connect, then if one ever had to change the core out agan, slide the hose off the pipes,slide in a new core,connect the 2 hoses, done deal,what I did works, but one has to use the core with the swivel ends in order to slide the short piece of hose over the pipes,took a hair longer to do and of course 2 hose clamps on each pipe, the other way,only one connection on each pipe, and would be absolutly no problem to manuver 2 rubber heater hoses onto the pipes. Actually I would of made the change I described BUT I didnt think of doin it till after I had the dash back in, mmmm, hindsight is 20-20, so they say, could also be age.
As for the other clamp that holds the 2 pipes down thats against the fire wall, that one you cant get a screw driver on, so just take a Dremil tool with a little cutter or blade or grindstone on it,lots of room to just reach in and grind the head of the small screw off,dont need the clamp back there at all anyway when one has hoses pass thru the firewall.
Now I know some of you guys and dolls will really cringe at the thought of what I did and what I will do next time, BUT I will modify just about anything that will make things easier,and in this case a couple of simple cuts propably saved a hour or so and more scraped fingers,dropped bolts and nuts, and a few choice words on top of it,not to mention cutting into my recreation time.

MERRY CHRISTMAS EVERYONE!!!!

 

All Done. Got Heat!

Dieselman, you were correct. The core was binding on the inside of the HVAC box. It took me approx. 6hrs. because of the problems I was having.

Thanks for the write-up & tips. I appreciate it!

 

Approx how much would you have to remove from the fire wall for this mod to work using a NON swivel heater core?

 

Wouldnt have to "remove" any of the firewall except enlarge the holes so the heater hoses fit thru,inside diameter of hoses is 5/8 so outside will be approx. 1and 1/8 diameter,I would cut them holes with a metal hole saw, then after the first bend of the pipes off the core,go maybe inch and a half and cut the pipes,snake the heater hose thru the firewall and slip them on the heater core pipes. put a clamp on each and your done.

 

I think the hoses would fit without hole sawing the firewall. There is a foam gasket that covers the hole. When I did mine the foam gasket disintegrated and I just perma-gummed the hole when I was done.
Permagum seals holes better anyways. I bought a 5# block about 4 years ago and still have about 3# left.

 

Isnt it nice to have heat

It was -9*F yesterday and -3*F this morning. I had to drive 60 miles to work this morning and I was VERY thankful I did the heater core.

 

Thanks for the info..... this is a trick we should all remember for the next heater core we do on these.

 

Hi Dieselman2300!!!
My '97 dodge ram 2500 heater core is leaking, and I was wondering if you could still send me the artical. I know it was dated 4 yrs ago!!!!! but some things never change right!
I have a friend who is a mechanic and hopefully he would be able to do it, with a little bit of help from me? I am a relatively new member, and I am impressed with all the information that is available on this site.
Thanks Dieselman much appreciated. Scotty.

 

Just did mine using the cut and splice method.
I decided against the thru firewall hose method because of the tight bend the hose needed to make at the heat tubes and no time to cut them longer and fuss around with that.

2.5 hrs start to finish and that included new hose in the engine compartment too.

I had some 1/4" x 1/2" closed cell foam weather strip and used that around the unit like the OEM and it fit great- nice and tight but not too tight.

Thanks to all who tested/created this short-cut method. Heat without open windows and no smell. What a treat!