0
Before starting, note that on the side of the van to the right of the heater, there is a vent with a vacuum actuator. This thing gets in the way and it turned out mine didn't do anything, at least after the job. I don't think it ever did. Suggest you fire up your engine and play with the heater controls while you watch the vent and see if it works. If not, you might want to leave its actuator off when you put the heater back in.
I found a set of small 1/4 inch drive sockets with extensions and a screwdriver type driver most helpful.
Doghouse hatch
- On the doghouse hatch, 2 screws behind cigaret lighter door, two large screws at bottom front, lift cupholder part off.
- two bolts at bottom left & right, clamps on either side to remove doghouse cover
Move Dashboard
- disconnect battery
- 3 bolts under front edge on the right (10 mm), 4 on left side
- 3 screws in steering wheel undercover
- 7 screws top of dash near windshield
- 1 screw behind and below the radio
- remove 2 big bolts to allow the steering wheel to rotate down and let the dashboard move back a little.
- support right side up and back with a plank about 2 feet long
- take pictures of everything
- remove 4 bolts on extreme left and right of metal base that held the dashboard, lift it up an inch so black plastic duct under it can be pulled back slightly
- hoses to side window defroster vents: slip screwdriver into front of vent, pry out. Easy to twist hose off when vent is free.
- I was afraid to unhook the electrical cables going to the instrument panel, but I did unhook all the wires going to the radio, which allowed the instrument panel to move out a lot further on the heater side.
heater
- support bar in front - 2 bolts on right side, 2 on left from inside insulation of doghouse, 3 vacuum lines to actuators to remove and remember.
- bolt into firewall behind and below heater
- duct on left side of heater - 2 screws at top
- temp adjust cable going to right side of heater - I pulled the nut-like holder off and it went back on later with no trouble.
- large duct going over the doghouse hump has big 7/16" bolt in part coming out to driver's side
- try to remove duct on heater right side (one screw): top slides out of lip, rotate up high to get out past actuator for vent in side of van. Carefully remember how you did it; very hard to get back in. If you don't get it, it will come out with the heater.
Under the hood
- remove rad overflow tank, air cleaner inlet duct to make room to work
- undo the main hose to the bottom of the radiator to let a pail of coolant out.
- locate air conditioner parts, connected with metal pipes and LEAVE THEM ALONE.
- the large black plastic air conditioner evaporator between the heater fan at extreme left and the engine is also left in place, but the 3 nuts holding the heater to the firewall are located at the upper left, upper right and lower right of this evaporator.
http://i122.Photobucket.com/albums/o276/Delphi51/GM%20van/P1030641.jpg
The nuts were invisible on my van because they were covered with black silicone gunk. The lower right one is hard to reach, behind a big cylinder of the air conditioning system. I had to use a 7/16 open end wrench on it. Other two no problem with socket extension.
- inlet and outlet heater hoses in same location as lower right nut must be removed from heater end. Note location and orientation of clamps. The hoses connect to the vacuum controlled valve that lets water flow into the heater core hoses when heat is turned on, bypass it when not. This valve with its 4 hose connectors is located under the big AC cylinder, but it is held only by the hoses.
http://i122.photobucket.com/albums/o276/Delphi51/GM%20van/P1030642.jpg
pull heater out
- Study the ducts still connected to the heater. I freed the big defrost on by lifting it up half an inch. The heater duct going over to the driver's side shifted left a half an inch with some encouragement.
- I had lots of trouble pulling the heater out because the threads of the 3 bolts going through to the engine side caught on the firewall. I had a helper push on them with a broom handle while I wiggled the heater.
http://i122.photobucket.com/albums/o276/Delphi51/GM%20van/P1030654.jpg
- Just a few screws in the heater to open it and remove the core.
Reassembly
- Reverse the process!
- The duct on the right side of the heater was a huge problem for me. I gave up and decided I would kludge something together to replace it. My 82 year old mechanic friend came over and got it in in an hour. He said he just "lifted it up high". Had I known the vent on the outside wall didn't work, I would have taken its actuator off to leave lots of room for the duct.
- I had trouble with the hoses on the engine side. The lower hose to the heater core puckered or bent and wouldn't go on properly. No problem when I got a new piece of hose.
- Surprisingly little trouble getting the dashboard back in place.
- Shortly after the reassembly, coolant began leaking from the area of the vacuum controlled valve connected to the heater core hoses. I finally unhooked all 4 hoses and took the thing out. We plugged three of the openings with fingers, connected the bottom (inlet) to a water hose and when the valve was pushed open with a finger, water squirted out the tiny hole where the actuator push rod goes in. Ordered a new one, $25.
http://i122.photobucket.com/albums/o276/Delphi51/GM%20van/P1030718.jpg
If the pictures don't show, email me harvey at softwarespirit.com.
What else can I help you with?
How do you remove the heater core from a 94 gmc vandura 2500?
To remove the heater core from a 1994 GMC Vandura 2500, start by disconnecting the battery and draining the coolant from the radiator. Remove the dashboard and the HVAC housing to access the heater core, which is typically located behind the dashboard on the passenger side. Disconnect the heater core hoses from the engine compartment, then unbolt the heater core from the HVAC housing and carefully pull it out. Reinstall the new heater core by reversing these steps.
How do you take the dash out to get to the heater core on a 89 gmc vandura?
You can do this without completely removing the dash. Just remove all the screws then remove the support bar underneath the passenger side of the dash. This should give you enough wiggle room to get the core out.
How do you change the heater core on a 1996 GMC half ton pickup?
The 1996 GMC half ton pickup truck heater core can be removed by removing the heater core retaining bolts. Remove the heater core water lines. Reverse the process to install the new heater core.
How do you remove the heater core in a 2002 Yukon a GMC?
read the instructions and find out!
How do you replace heater core on 2000 gmc sierra 1500?
take the dash apart and remove nessesary items to replace heater core
How do you remove heater core 1987 GMC vandura?
Is located right side under the dash board, you need to remove a few screws that hold the dash and lift dash board as much as needed to see heater core, don't forget to drain coolant from radiator and remove hoses from inside engine compartment , lost of patient needed for this job, good luck
How do you replace the Heater Core in a 1992 GMC Vandura 2500?
You disconnect the hoses. Then remove the heater core cover from the engine compartment (oblong black thing bolted to the firewall on your left hand side, looking in). Wrestle that off and extract the heater core...swap out your new core and replace it all. It is that easy. I put in a coolant flush kit while I had it apart...flush your coolant system every few months for nothing. Good luck
How to replace a heater core in a 1992 GMC Jimmy?
I need to know how to replace a heater core in a 1992 GMC Jimmy?
How do you replace heater core on a 95 gmc sonoma?
To replace the heater core on a 1995 GMC Sonoma, first, disconnect the negative battery cable and drain the cooling system. Remove the dashboard and center console to access the heater core housing. Disconnect the heater hoses from the core, unbolt the housing, and replace the old heater core with a new one. Reassemble everything in reverse order, refill the cooling system, and check for leaks.
How do you install a heater core in a gmc sierra 1500 4.3L v6?
how do you install a heater core for a 2003 gmc sierra 4.3l truck
How do you change heater core on 2001 gmc pickup?
You should probably bring it to a mechanic because it is very difficult to replace the heater core on GMC pickups.
How do you replace 2004 GMC sierra heater core?
I believe the heater core in that vehicle is located behind the dashboard.
