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I rebuilt the heater box and evap core box from our '77. Typically, they call for 3 oz. of oil in the evap core to replace what you lost in the old one. Since the rest of the AC system won't be installed for some time, I will leave the evap core capped for now. Should I leave it dry (no oil) since it will be attached to a completely new AC system down the road?
May run a little RTV black, silicone seal around the cap edges.....
but one thing I would do, long as you got it all out, is make/buy a 3/4 inch spacer for the blower motor and install a C4 blower motor.....more power.....another trick, is to block off the fresh air intake and put it on permanent recirculation, mainly to keep the dirt/crap outta the blower/pressure side of the evap coil....
seal the outside flapper shut under the fender, remove the inside flapper behind the kick panel....
May run a little RTV black, silicone seal around the cap edges.....
but one thing I would do, long as you got it all out, is make/buy a 3/4 inch spacer for the blower motor and install a C4 blower motor.....more power.....another trick, is to block off the fresh air intake and put it on permanent recirculation, mainly to keep the dirt/crap outta the blower/pressure side of the evap coil....
seal the outside flapper shut under the fender, remove the inside flapper behind the kick panel....
Thanks MR - I still need to add the sealant around the tubes, so I could add a little around the box seam as well. I thought about the C4 fan swap idea, but wasn't sure if the wiring is different. I don't want to cut / splice my new Lectric harnesses.
How would I block off the fresh air door? Very limited room for access.
EDIT: I see the only thing I need is the cage for the C4. So I'll order one of those and make the spacer. Thanks again.
I rebuilt the heater box and evap core box from our '77. Typically, they call for 3 oz. of oil in the evap core to replace what you lost in the old one. Since the rest of the AC system won't be installed for some time, I will leave the evap core capped for now. Should I leave it dry (no oil) since it will be attached to a completely new AC system down the road?
Thanks,
Adam
You should store it dry just as it is.
The caps simply prevent contamination until installation.
Refrigerant oil is added to the system during assembly - refrigerant oil is highly hygroscopic and should not be opened until you're ready to seal up the system. Moisture is your enemy in HVAC work and ALL moisture will be removed (boiled off) when you properly evacuate the system prior to charging it.
Last edited by Hammerhead Fred; Apr 10, 2019 at 07:48 PM.
You should store it dry just as it is.
The caps simply prevent contamination until installation.
Refrigerant oil is added to the system during assembly - refrigerant oil is highly hygroscopic and should not be opened until you're ready to seal up the system. Moisture is your enemy in HVAC work and ALL moisture will be removed (boiled off) when you properly evacuate the system prior to charging it.
Thanks Hammerhead for confirming what I suspected. I'll just leave it capped and dry.
New Evap Core - Add Compressor Oil?
