You don't want to just pull one of the couplers to drain the system. It is under rather good pressure, and you probably wouldn't like the results.

If you don't use it, no need to charge it.

You CAN install the rigid pipe heater core without discharging the a/c, its just a pita.

 

thanx heyyou . wondering how i discharge ac lines ? also are you 100% sure i dont have to recharge ac system , i ask because a local pro mechanic told me if they did job lines would have to be recharged . though maybe thats just him making money , or maybe its some type law .

 

Can someone please share pics of when they replaced heater core through glivebox without touching or draining freon from A/C? I'd like to try doing that. I think I remember it being posted by member "working for ev4".....but pictures are no longer available.

I would greatly appreciate it,

Thanks,
Luie

 

That's not going to happen. It cannot be done. You have to move the instrument panel out of the way.

With the instrument panel out of the way, you can get just barely enough room to do the job without discharging the AC by pulling the HVAC box away from the firewall until the couplers hit on the engine compartment side. I cut the heater core pipes off and shoved them through to the engine side, myself.

 

You can do it through the glove box without removing the instrument cluster. Remove five screws from top of dash along windshield. Remove glove box. Remove knee guard underneath steering column. Remove small gear selector wire from holder. Two bolts on steering column can be removed and drop the steering column to seat. Remove kick panels on both sides. Loosen bolt on each side. Dash can now freely pivot back towards seat as well as be lifted up if needed. I have used a ratchet strap to pick up and hold dash using the Oh Sh*t handle on passenger side. Cut lines I engine bay. Small amount of coolant loss. Remove hoses and also cut excess from existing heater core pipes. Once hoses are off, use metal cutters, and reach through side or through glove box opening and cut both pipes close to the actual heater core itself. There are two tabs holding pipes down. Use a screw driver and remove them. Pull pipes through firewall. You can now pull up and remove core. Clean out with rag as best you can. With new core, pivot arms towards firewall holes and work it into slot at an angle. It takes time and you might have to force it just slightly. It will eventually fall into place. Replace tabs over pipes. Install now hose onto new pipes and tie into existing water lines. Replace dash same way as removed. Top coolant off and your done. I've done 4 pickups this way. With wish I had pics but I don't.

 

If you're rocking the instrument panel, then dammit you're not doing it through the glove box.

 

I misinterpreted what you meant lol my bad.

 

So I know this is a few years late, but I had to respond. This really does work with a heater core that has the movable pipes. I just did it on a customer’s truck for kicks, and it took me 2 hours at a snails pace to change the heater core. I’m forever sold on this procedure.