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Discussion Starter #1
Replacing my heater core in our 2009. Anyone run other lines inside rather then pull the dash again? If so how( did you reroute) and how did it hold up for you? I'm looking at running rubber inside and cutting some of the metal line away on the new core. So I can slide any other future replacements in and out under the dash. Don't really want to disassemble the dash again.
 

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I just did an LS3 swap a couple months back and found the heater started blowing cold air in the left-most vent. Checking online came back with the general thought that this is a failing core, tear apart the dash, replace, etc....

I read, too, about a dude that used some CLR (calcium, lime, rust remover) and let it cook in his core for 30 minutes or so, flushed and had a fully functional core again.

I pulled the hoses, made a huge mess (hate doing this--barely had the garage mopped back up from the swap, damn-it!), back flushed, forward flushed (used a garden hose and blew air through--did not pressurize the core, of course). After that I filled with CLR and let it sit for 10 minutes, flushed again back and forth. I repeated this once more and got to the point that the water just looked clear and nice and no particulate matter.

Reassembled and it's been perfect!

If your core isn't leaking, give it a go. Nothing to lose. It may not really help or answer your question here, but this saved me from ripping out my dash.

-Randy
 

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I just did an LS3 swap a couple months back and found the heater started blowing cold air in the left-most vent. Checking online came back with the general thought that this is a failing core, tear apart the dash, replace, etc....

I read, too, about a dude that used some CLR (calcium, lime, rust remover) and let it cook in his core for 30 minutes or so, flushed and had a fully functional core again.

I pulled the hoses, made a huge mess (hate doing this--barely had the garage mopped back up from the swap, damn-it!), back flushed, forward flushed (used a garden hose and blew air through--did not pressurize the core, of course). After that I filled with CLR and let it sit for 10 minutes, flushed again back and forth. I repeated this once more and got to the point that the water just looked clear and nice and no particulate matter.

Reassembled and it's been perfect!

If your core isn't leaking, give it a go. Nothing to lose. It may not really help or answer your question here, but this saved me from ripping out my dash.

-Randy
Good info Randy. Haven't needed to do this, but that's a great idea.
 

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I just did an LS3 swap a couple months back and found the heater started blowing cold air in the left-most vent. Checking online came back with the general thought that this is a failing core, tear apart the dash, replace, etc....

I read, too, about a dude that used some CLR (calcium, lime, rust remover) and let it cook in his core for 30 minutes or so, flushed and had a fully functional core again.

I pulled the hoses, made a huge mess (hate doing this--barely had the garage mopped back up from the swap, damn-it!), back flushed, forward flushed (used a garden hose and blew air through--did not pressurize the core, of course). After that I filled with CLR and let it sit for 10 minutes, flushed again back and forth. I repeated this once more and got to the point that the water just looked clear and nice and no particulate matter.

Reassembled and it's been perfect!

If your core isn't leaking, give it a go. Nothing to lose. It may not really help or answer your question here, but this saved me from ripping out my dash.

-Randy
Good stuff getting it going. This isnt direcetd at you but anyone who is thinking about using that CLR may want to think twice. That stuff doesnt play well with aluminum I hear.
 

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Discussion Starter #5
I've been working on the heater core when I get the time. Mine was leaking at the crimped lower pipe seal. I decided to get another core. It came Mon. PM. I cut the lines on the leaking core and pulled them out thru the firewall. That left me the room to slide the old core out. I then cut the firewall to the right, enough to let me slide copper flex line inside. I cut the new heater core lines at approx. 5", slid it in and ran rubber between the copper and the core. Ran rubber off the engine and pump to the copper. I'm going to use spray foam to seal around the new copper lines. If I ever have to replace again, all I have to do is unhook the rubber under the dash and slide old out and new in. Don't know why they didn't run the lines to the right of center from new. It would have given enough room that the dash wouldn't have to be removed.
 

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Discussion Starter #7
Taking as I go I'll post when I get it finished. Should be ready for antifreeze today. Still have run test before I reinstall dash tupperware.
 

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Good stuff getting it going. This isnt direcetd at you but anyone who is thinking about using that CLR may want to think twice. That stuff doesnt play well with aluminum I hear.
I agree--it's an acid, but in my case: 8 hours to R&R the heater core (plus buying one) or trying the flush. I figured I had little to lose, and at that, 10 minutes diluted exposure seemed safe enough.

You mileage may vary.

-Randy
 

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Why the fuck would some dumb ass engineer decide that it was a good idea to have to take the dash apart to change something like that?

I am assuming the double hose clamps on the core end are just added insurance?
 

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Discussion Starter #12
Yes to the double clamps. If it leaks I'd rather its not inside again. As to the engineer. Why would you put two 90 degree bends in those pipes when there is room to move the opening over in the firewall and do a straight run inside.
 

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I had a leak in the elbow of the lower hose which was caused by the hose rubbing from vibration on the firewall. I cut the bad part off and used a 3/8" galvanized pipe nipple (3" short) and two stainless hose clamps. I then cut up a larger heater hose and placed them on each elbow OD. The engineer that designed the routing for the tubing should be fired and sent to work for Yugo or Hillary's campaign manager. :mad:
 
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