Heater core

Tiny
ITSRONDO
  • MEMBER
  • 2004 CHEVROLET BLAZER
  • 6 CYL
  • 2WD
  • AUTOMATIC
  • 10,000 MILES
How do I remove the heater core?
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Thursday, June 10th, 2010 AT 9:46 PM

44 Replies

Tiny
BLUELIGHTNIN6
  • EXPERT
Hello,

Start by disconnecting the battery and you will need to vacuum the AC system and drain the coolant out. Here is a guide that will help and the instructions for doing the job are in the diagrams below.

https://www.2carpros.com/articles/re-charge-an-air-conditioner-system

and this is an older truck but you get the idea, check the diagrams below to replace the heater core in your truck.

https://www.2carpros.com/articles/replace-heater-core

Check out the diagrams (Below). Please let us know if you need anything else to get the problem fixed.
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Thursday, June 10th, 2010 AT 9:56 PM
Tiny
MREEP
  • MEMBER
  • 2000 CHEVROLET BLAZER
Heater problem
2000 Chevy Blazer 6 cyl Four Wheel Drive Automatic 81, ooo miles

I need to replace heater core in 2000 blazer. I have the part but it looks like I have to pull whole dash out. I have had to replace ingine and just replaced the raditor so dont have the money to pay some one to do it. Please HELP!
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Thursday, December 27th, 2018 AT 8:11 PM (Merged)
Tiny
BLUELIGHTNIN6
  • EXPERT


http://www.2carpros.com/forum/automotive_pictures/261618_Noname_1999.jpg

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Thursday, December 27th, 2018 AT 8:11 PM (Merged)
Tiny
MENDOZAH
  • MEMBER
  • 2001 CHEVROLET BLAZER
  • 6 CYL
  • 4WD
  • AUTOMATIC
  • 97,000 MILES
The heater core on our 2001 Chevy Blazer is failing and needs replaced. When replacing the heater core, is it necessary to drain the air conditioner coolant? Purging and recharging the a/c is very expensive if it is not absolutely necessary. Thanks for your advice.
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Thursday, December 27th, 2018 AT 8:11 PM (Merged)
Tiny
SCOTTY DEE
  • MEMBER
You won't have to pull the A/C system down but you will need to remove some coolant.
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Thursday, December 27th, 2018 AT 8:11 PM (Merged)
Tiny
PAINTERGIRL0319
  • MEMBER
  • 2001 CHEVROLET BLAZER
Heater problem
2001 Chevy Blazer 6 cyl Two Wheel Drive Manual

Just replaced the heater core. I have heat and no more leak. Without tuning on anything while driving. Air is coming out of the vents.. Can adjust the temp by just turnig the temp dial? When I do turn on the heat it comes out of all of the vents. Floor and the defrosters. So I have no control on the dials. What is wrong? Just happy for heat.
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Thursday, December 27th, 2018 AT 8:11 PM (Merged)
Tiny
JACOBANDNICKOLAS
  • EXPERT
In this case, you are looking for a vacuum leak. The vent doors are actuated by vacuum. Check under the dash and under the hood for disconnected or damaged hoses that would cause this. By accident, you may have forgotten to replace one or bumped one.

Let me know what you find.
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Thursday, December 27th, 2018 AT 8:11 PM (Merged)
Tiny
SERVICE WRITER
  • EXPERT
There is probably an electrical connector that was not hooked back up to the HVAC Module which is removed to replace the heater core.


http://www.2carpros.com/forum/automotive_pictures/30961_xabla_1.jpg



Check to make sure there is not a connector not hooked up or some controls will not work.
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Thursday, December 27th, 2018 AT 8:11 PM (Merged)
Tiny
PAINTERGIRL0319
  • MEMBER
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Thursday, December 27th, 2018 AT 8:11 PM (Merged)
Tiny
PAINTERGIRL0319
  • MEMBER
The door actuater on top of the heater core is that run on electric or vaccuum?
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Thursday, December 27th, 2018 AT 8:11 PM (Merged)
Tiny
SERVICE WRITER
  • EXPERT
My BAd, J&N would be correct that it is vacuum not electrical. Was thinking something wasn't re-installed right but was thinking electrical.
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Thursday, December 27th, 2018 AT 8:11 PM (Merged)
Tiny
PERCYK
  • MEMBER
  • 2000 CHEVROLET BLAZER
  • 6 CYL
  • 2WD
  • AUTOMATIC
  • 178,000 MILES
I think our heater core is the problem, but Im not a professional so I am here. Ha! Anyway. When I turn on the heater, the windows get fogged up and so I bought a heater core thinking that was the problem. But now I have no idea of how to replace this thing so I am asking you?
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Thursday, December 27th, 2018 AT 8:11 PM (Merged)
Tiny
BLUELIGHTNIN6
  • EXPERT
Heres the best way to describe how to replace heater core in a 2000 blazer..


http://www.2carpros.com/forum/automotive_pictures/261618_Noname_1754.jpg

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Thursday, December 27th, 2018 AT 8:11 PM (Merged)
Tiny
LJK730
  • MEMBER
  • 2000 CHEVROLET BLAZER
My husband needs to replace the heater core in his 2000 2DR, 4WD blazer with AC, which presently has about 80,000 miles. However, and understandably, he is a little concerned as to how involved this will be because he will need to remove the steering column and dash. Any suggestions/recommendations? Please! And thanks!
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Thursday, December 27th, 2018 AT 8:11 PM (Merged)
Tiny
LOSONE
  • MEMBER
It is about an 8 hour rough job for an experienced mechanic. For a novice about 3 days and many bloody knuckles and (*&(*& T)*)
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Thursday, December 27th, 2018 AT 8:11 PM (Merged)
Tiny
CBRO3
  • MEMBER
  • 2001 CHEVROLET BLAZER
  • 6 CYL
  • 4WD
  • AUTOMATIC
  • 175,000 MILES
Need to fig out what all do I need to take out of the dash to remove and install the heater core like where do you start iv replaced them before just not in this vehicle this thing has got my mind boggled
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Thursday, December 27th, 2018 AT 8:11 PM (Merged)
Tiny
BLUELIGHTNIN6
  • EXPERT
Removal & Installation

Remove the HVAC module-auxiliary.
Remove the screws from heater core cover-auxiliary from the HVAC module-auxiliary.
Remove the heater core cover-auxiliary.
Remove the HVAC module pass thru seal-auxiliary.
Remove the heater core-auxiliary from the HVAC module-auxiliary.
To install:

Install the heater core-auxiliary to the HVAC module-auxiliary.
Install the HVAC module pass thru seal-auxiliary.
Install the heater core access cover-auxiliary to the HVAC module-auxiliary.
Install the screws to the heater core access cover-auxiliary and tighten to 18 inch lbs. (2 Nm).
Install the HVAC module-auxiliary.

HVAC MODULE REMOVAL/INSTALLATION:
Removal & Installation

Drain the cooling system.
Raise and support the vehicle.
Remove the nuts from rear A/C line block fittings. NOTE
Cap or tape the open A/C refrigerant lines immediately.
Remove the A/C line block fittings and discard the O-ring seals.
Remove the nuts from the heater hoses block fittings.
Remove the heater hoses block fittings from the HVAC module-auxiliary.
Remove the nuts from the HVAC module studs.
Lower the vehicle.
Remove the right side rear quarter trim.
Disconnect the electrical connectors from the HVAC module.
Disconnect the rear compartment air outlet ducts from the HVAC module.
Remove the mounting bolts from the HVAC module.
Remove the HVAC module.
Remove and discard the HVAC module pass through seal.
To install:

Install new HVAC module pass through seal.
Install the HVAC module.
Install the HVAC module mounting bolts and tighten to 89 inch lbs. (10 Nm).
Install the air outlet ducts.
Connect the electrical connectors.
Install the right side rear quarter trim panel.
Raise and support the vehicle.
Connect the heater hoses to the heater core.
Install the nuts to the HVAC module studs. Tighten the nuts to 89 inch lbs. (10 Nm).
Remove the cap or tape from the A/C lines.
Install the new O-ring seals.
Install the nuts to the evaporator core studs and tighten to 15 ft. Lbs. (20 Nm).
Lower the vehicle.
Fill the cooling system.
Evacuate and charge the system.
Leak test the fitting of the component.

Thanks for using 2CarPros. Com!
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Thursday, December 27th, 2018 AT 8:11 PM (Merged)
Tiny
LOISENGLENY
  • MEMBER
  • 2000 CHEVROLET BLAZER
Heater problem
2000 Chevy Blazer 6 cyl Two Wheel Drive Automatic

Hi! My heater core went and I am having someone replace it. He has had my vehicle for two days now. I called today and he stated that he can't get the heater box out of the way to get to the heater core. He says he only found two bolts. Where are the others? Please help. My truck has been broken down for weeks.I need my ride! :(
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Thursday, December 27th, 2018 AT 8:11 PM (Merged)
Tiny
BLUELIGHTNIN6
  • EXPERT
Here's a tip to give your repair person.

" I started by taking the hoses aloose. Then move the blower resister. Look down in there---unscrew a bolt going the firewall into the blower housing. There is a stud coming through the firewall in the middle. Takes 7/16 socket--take care of that one. Now go to the inside and take the whole dash and put it in the backseat. Scews at the top. A 10mm headed bolt on each side. Drop the column down. Need to do some unplugging. Remove glovebox and you got a big electrical connector-use 7mm socket. A vac. Connector. Get some slack going for the ant. Cable. IMPORTANT-- Take aloose one connector at bcm(plastic box in middle). The one at the top going to dash.I almost pulled it by the roots. After pulling the dash back a little you will see a connector on driver's side with big wires---get it. And get the ant. Cable out the back of radio. None of this bad to do. The housing has a 10mm headed bolt at bottom and two screws coming in backwards through the firewall. Undo the bolt. I used a hammer and big screwwdriver on the other two underthere. Yank back-do the core"

See if that helps them out.
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Thursday, December 27th, 2018 AT 8:11 PM (Merged)
Tiny
CARLOS_GONZALEZ_JR
  • MEMBER
  • 2002 CHEVROLET BLAZER
Heater problem
2002 Chevy Blazer 6 cyl Two Wheel Drive Automatic

What is the process of heater core replacement
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Thursday, December 27th, 2018 AT 8:11 PM (Merged)

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