How to by-pass heater core?

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Mar 15, 2006
Las Cruces, NM
Still working on the cooling syst. Just put in a new radiator and it still over heats!:mad: I'm hoping that I may be able to bypass the heater core(s) front and rear. I did a search and came up with threads talking about by passing at the fire wall. Does any one have any pics of this by pass? Does it eliminate the heater control? Which hoses to conect? Perhaps I shouldn't rule out the thermostat just yet... Don't have a whole lot of time these days, just thought doing the heater core by pass would be quicker and would help me come to some sort of conclusion as to why this thing is still overheating so quickly! Any suggestions?
Thanks in advance,
I can snap a pic of my heater hoses, my rear heater is disconnected at the engine bay.
Ill take a pic this weekend when im home with my truck.
Did it all the sudden start overheating? What did you do before it started overheating?

Does it start overheating just at idle?

What are you measuring the temperature with?

You can bypass the rear heater core under the cruiser. I am thinking when you slide the temp control switch between cold & warm it sends water to the heater cores and when closed it uses the bypass. You sure you have the hoses all right? I got some help in this thread.
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Why don't you just reach under your hood and connect the one that goes over the rear portion of your valve cover too the one that runs by your distributor?

If your overheating problems go away, great you know you have a plugged core. You can then diagnose which core.

If your probelm is still there then you have ruled out the cores.

There are a lot of reasons it can overheat.

Did I read the first post correctly that you replaced the radiator before you replaced the thermostat?.

I think you are making this really hard on yourself.
Yeah, this thing was and still is overheating at idle and while on the road... it makes no differance. And I'm just going off of the therm gage on the dash. It gets close to the red and fast!

Yeah, I maybe making it hard on myself... but having changed out the rad is not the reason for the difficulty. I had the rad inspected, to see if it could be repaired, and the radiator guy said that he could fix the (many) pin holes but that it would just get worse in the long run. He continued to mention metal fatigue and the fact that it had been repaired so many times before... he couldn't garantee the work so I got a good deal on a new one and installed it myself! I'm guessing it's the t'stat giving me the overheating problems. Just want to rule out the heater cores as it seems to be easier to do first. I understand that when going in after the t'stat you have to be prepared to back out some busted t'stat housing bolds. Want to rule out other things before I go there. Ya Dig??? If there is a better route let me know.
is your fan pullin air ??? does the temp go down if you turn on the heater/s are that hot ??

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