73gitane

I’ve got a ’92 GMC Vandura van with a leaky heater core. From what I’ve read on the web I will need to remove the dash or at least loosen it enough to angle it away so I can get access to the heater box. Sounds like a real pain but doable. It has air conditioning so I assume I will have to have the air conditioner coolant evacuated.

I’ve seen two references on the web that state that cutting the dash along a false seam on the passenger side will greatly speed up the repair. Has anyone done this? If you have removed the dash the official way could you speculate that making this cut would work? As old as it is I’m no too concerned about cosmetics at this point. Thanks!

RacerX

bad move.

just unbolt the dash at the bottom. 13mm screws, 3 of them and pull the dash away from the window. Once dash is free the core is right there.

You dont have to discharge the AC. but you will have to remove the coolant lines from the engine area(replace with new).

73gitane

Thanks I have not seen any diagram on this heater box. I think I assumed that the box you can see from the engine compartment as well as the box you can see from the interior all come out for the heater core repair. If that was the case it looked like the air conditioner dryer would have to be removed letting out the Freon.

73gitane

OK, glad I didn't cut the dash. I ended up removing the dash as it just made getting to the heater box easier. Sure, it took a little longer but oh well I've had worse repairs.

RacerX

yea, it isnt hard just time consuming is all

lunghd

Know it's an old post but wanted to follow up as I think I'm the one you're referring to who posted that 'cut the seams to save time' thread elsewhere (At Edmunds, or All Answers??? not sure - wrote it while figuring same issue out waybackwhen).

Yeah, for a work van definitely just cut the dash with a dremel along the faux seams and call it a day. It doesn't look that bad if you take your time given that there is a precast 'false seam' already there. Just use it as a guide to follow along then you only have a half-dozen or so screws to remove. My old G20 was eating heater cores like they were candy and after pulling the dash & dealing with ten thousand little screws my back and bifocals said 'Thehellwithit...' and just cut the dash.

There is a voltage differential that comes about in the G20 vans that seems to generate corrosion in the heater cores - dunno why, electrolysis most likely compounded by plastic tanks creating a poor ground to bleed off the generated voltages. You can put one lead of a digital volt meter in the antifreeze neck on the radiator and touch the other lead to ground and you'll get a small voltage reading. That's what kills these heater cores. (Along with cheap heater cores...)