carriljc

I've lived in warm areas most of my life and I have bypassed heater hoses by just re-routing the flow by tying the supply hose to the return hose.
If you can live without heat for testing this is rather easy and maintains the flowpath active such that you can, more or less, do a pretty good evaluation to check where the fluid loss is occurring.

Dallasfool

thanks for your help, that does sound better for now, what size valve do I need to get? both hoses look to be the same size? after watching a you tube video on it (heater core ), it would probably take me a month to do it, while I was replacing my door lock actuator(that wasn't fun), the 300 dollar battery went dead, after I jumped it off, I let my 1980 run for about 30 minutes, then I notice anti-freeze, running on garage floor ,this was on 11/21/17, so on 11/22/17 I jacked up passenger side and looked under it, notice small drip on of them hoses going to heater core, so I started it up, let run again for 30 minutes, turn heat on and off and nothing was leaking? checked again today (11/23/17 with a piece of cardboard I placed underneath the night before, and about an one inch drip on it! I pulled carpet back and its still dry, checked clamps on the hoses they are all tight, one more question, when I place inside control on vent, will it still work? I don't plan on driving the car below 60 degrees or higher than 90 degrees, again I do appreciate every ones help, don't know if I trust my local mechanic shop to replace it, or take it to dealership are they are sponsor for local corvette club, tks! again

C3w4sp

No need for a valve, just get a PVC or other plastic inside dia nipple / sleeve / connector, and 2 hose clamps. Cut the hoses, connect them to each other, secure it out of the way until you tackle the core replacement.

carriljc

I would not recommend PVC (I believe it begins distorting at ~140°F ---somebody can check me on that) so just use some metal connector-should be cheap at hardware store. And I agree there is no need for a valve.

carriljc

I went and looked it up (I don't like spewing TOO much b.s. ) Here you go, max recommended operating temp is 140°F for PVC.
http://www.heritageplastics.com/tech...ture-pvc-pipe/

Big2Bird

Dorman makes an ABS 5/8"x3/4" connector just for this. About $2.00

cardo0

Don't know if the OP finished this HC replacement yet but just wanted to mention I gave up on using the "monkey �� poop" for sealing the A/C boxes and used blue RTV instead. It works.

As for a good heater core I just looked over the replacement at several parts store and bought the one I felt comfortable with. It still had to be tweaked to fit right. I don't think there is an ACDelco replacement anymore.

Good idea once you have the heater core out to replace all the foam seals on the ventilation box under the dash to. I found mine all rotted away and plenty of hot engine compartment air just flowed into the pass compartment all the time.

Hope this isn't too late to help.

HeadsU.P.

Correct. Dorman # 47080
5/8 on one end
3/4 on the other.
Coolant temps compatable.

C3w4sp

Yikes, my bad on the PVC, yeah, didn't know that. Don't use that.