i have a 91 b350 that the heater core went out on i have the new heater core but i dont know how to get to the old one to get it out. any help would be appreciated

 

does anyone have a step by step process for removing the box to get to the heater core? I have removed all the nuts and self tapping screws in side the cab and one on the firewall but still cannot get the box out. I know I have to remove the A/C connection to the A/C evap. but even after that it looks like there is no room. Would love to remove the fender but it is not bolted on but welded. This is a 93 B350.

 

Define "all", how many is that? Without telling us how many you removed, how can we tell you if you missed one? Did you also disconnect the linkage that passes through the firewall?

 

I removed all the sheet metal nuts on the inside and one on the firewall on the right side upper. I disconnected the air paddle linkage.
Am wondering if the fan assembly that is connected to the bottom side has to come out with the box. It appears it has to since there is really no way to get to the self tapping screws. I have to un-bolt the A/C attached to the front of the A/C Coils. I then understand I have to remove the headlight and the other items in front of the box. It just seems like the box should move a little away from firewall which I am not seeing.



The box with the A/C ...note the rear A/C lines are cut off and sealed There are also two screws at the front of the box that go into the lower fan box. Those have to be removed so the upper box can then be pulled out. The fan box below does not come out with the box holding the A/C coils and heater coils.



This is the area behind the glove box which does not show any bolts that have to be loosened. BUT IF YOU remove that box there is one behind it that holds the top of the box and is the ONE that keeps it from coming out.



Here is the section where all the bolts with sheet metal nuts removed. This is below the duct work that is only attached with self tapping screws.



This is the single sheet metal screw on the firewall

 

Again you failed to say how many. If you say "all" and removed 5 when there are 10, did you really remove them "all?"

 

I did find them...i am going to post my whole story for others since there does not seem to be anyone who has done this on this model van. There are sheet metal nuts on the inside of the van...BUT behind the glove box there is one more that you can not see since there is an electronic model hiding it. I removed that. with difficulty and there was the one that was hold everything up. With that one removed and the one in the engine on the upper right of the "box" it comes loose but you also have to remove two long screws that hold the top box onto the lower box that contains the fan. Did not know that those two came apart. Now the whole upper box is free. I still have to unhook the A/C and remove the headlight etc. But that is straight forward. I will take pictures of the placement of the elusive nut behind the glove box so others won't pull their hair out.

 

Cool.

FWIW I had a tech do this job for me . It was worth it.

Thanks for the info.

 

Here is the final tip. There are not one but two sheet metal nuts behind the glove box. One behind the electrical box and another under some insulation in the far right corner. Once those TWO nuts are off the box slides right out and up once you undo the A/C connection and few electrical connections. Once the box is out you can see the lower box with the fan and it all is easy. No need to remove headlight or grill like the Chilton manual says. I change out the heater core. Cleaned the box. Remove the cover over the fan box and made sure it was clean and then put everything back. Recharge the A/C and hooked up the connectors and heater hoses and the job is done. The nuts behind the glove box that are hidden are the Bitches you have to find. There are two not one.

 

Once you know where the nuts are it is not that difficult a job. You do have to evacuate the A/C but we have gauges to do that and then fill back up. Did not have to remove headlights or grill just find those 6 nuts and remove the two long screws that holds the top box to the bottom box and then it pulls right out. OH you do have to move the A/C dryer too but it is just held in place with two bolts....after that it all swings away. There are a few connectors you have to unplug and then it comes out.

 

Great info...much obliged.