Replacing the rear heater core

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mmrseed

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This morning I smelled coolant while driving and when I stopped I saw coolant dripping out of a hose at the rear of my 99 expy. It appears that I may need to replace the rear heater core. Is this something thatan average joe (my name's not joe) should be able to do outside of the a/c flush and recharge? It doesn't seem difficult...just disconnect the old core from the hoses and replace....am I missing some secret hidden difficult issue? Thanks all
 
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mmrseed

mmrseed

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nevermind...got it done...3 hours to tear down....20 minutes to put it all back. What an education
 
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mmrseed

mmrseed

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too stressed at the time to take pics but it basically boils down to-

drain radiator (luckily mine was mostly drained thanks to this stupid heater core)

open rear hatch and remove
- rear seat
- rear hatch skid plate
- c pillar plastic cover (driver side) (you will need to disconnect seatbelt)
- b pillar plastic cover (driver side) (you will need to disconnect seatbelt)
- rear A/C plastic vent (thick black tube right under the b pillar plate)
- 2nd row seating skid plate
- plastic kick panel to expose the rear heater core assembly (there is a hidden pin under the carpet attaching it to the floor of the truck)

Disconnect the two hoses at the bottom of the heater core assembly

Then loosen and disconnect the two bolts on the metal tubing for the A/C (be careful you will get some green dye spray as the refridgerant blows out, so loosen lightly at first and it will just drip down through the floor of the truck)

Disconnect the 7 parts to the wiring harness from the truck to the plastic heater core assembly (you cant miss them)

Loosen the two brass bolts holding the assembly to the truck

Turn the assembly over and there will be 10 small bolts to take off and underneath that is the heater assembly...it just comes straight out. Replace and do the whole process in reverse.

I was quoted about $500 for this. The part was $60 and I will have to pay to recharge the a/c...that's it
 

toms89

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You da man! LOL

Thanks for the write up!
 

rixemailfl

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Here I go...

Looks like I get to tackle this job... Ugh!

Is coolant leaking from the rear heater core drip tube the indication that it needs replaced?
 

IMINYOURCHAIR

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yeah, and as for the ac part goes, go to a dealer and have the gas recovered. you can rent the tools to re charge it yourself. I got 5 cans of r-134a for about $65 because I didn't wait and order it in bulk, you can get a 12 pack for $50 last I checked. it's $300 deposit on the tool rental but it's 100% refund when you're done.

also, I would inspect the orifice tube for abnormal debris and replace the high/low side valve stems while it is degassed. the high side valve tends to leak and the orifice tube can tell you if you have a compressor in pre failing stage.
 
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