Heater core delete or bypass?

[BlackNoma]

I have read conflicting information on the coolant lines that go through the heater core.

Some say you can put a valve in the hot line off the engine to the core to block it off right there and the coolant doesn't need to circulate.

Others say you have to create a loop to keep coolant flowing if you want to bypass your core.

So what is it? Can I put a valve in to block it off in the summer for a cooler AC? Or do I have to rig up a valved/loop system?

Thank you for the clarification!! You guys are awesome.

Edit:
Also, what side ID is the hose? 5/8?

 

[riphip]

Valve like GPD 8211250 is a 4 port. 2 hose from heater core & 2 from block/WP. T the vacuum line that goes to blend door for AC dash pot over the heater motor. When air is selected, it will cut off flow to heater core from engine.

Google GPD 8211250. Rock Auto is under $10

 

[BlackNoma]

I would put a manual valve in. I live in South Texas. We have 5 weekends a year of weather below 60 degrees.

Does it NEED to circulate or not?

 

[riphip]

Is what I use in my 86. When you are not running AC it will circulate. Not circulating will give you a better chance of stopping up the heater core from deposits settling

 

[Thewespaul]

I just pull a line off and loop it during the summer, don’t need any heat in the cab during summers in Texas

 

[BlackNoma]

I just pull a line off and loop it during the summer, don’t need any heat in the cab during summers in Texas

So it needs to circulate?

I have a plan if it does, but a single in line valve to block off the core with a 1/4 turn to block the entire system would be way easier. But it wouldn't circulate that way.

 

[BlackNoma]

You can also add " or spring. Or fall. Or winter." To that statement, Wes. Haha

 

[Thewespaul]

No it does not need to circulate

 

[Thewespaul]

You can also add " or spring. Or fall. Or winter." To that statement, Wes. Haha

We’ve only got two seasons here, drought and flood haha

 

[BlackNoma]

Haha, it's true.

Thanks!

 

[riphip]

In youse guys area, may want to bypass, run clear water thru heater core to clean out really good, vacuum water out and cap off both pipes.

 

[79jasper]

Or..........
Be like the kewl crowd and run a vacuum valve.....

Sent from my SAMSUNG-SM-G930A using Tapatalk

 

[renjaminfrankln]

Valve like GPD 8211250 is a 4 port. 2 hose from heater core & 2 from block/WP. T the vacuum line that goes to blend door for AC dash pot over the heater motor. When air is selected, it will cut off flow to heater core from engine.

Google GPD 8211250. Rock Auto is under $10

Anyone got a pic of exactly which vacuum line to tee into?

 

[genscripter]

So it needs to circulate?

I have a plan if it does, but a single in line valve to block off the core with a 1/4 turn to block the entire system would be way easier. But it wouldn't circulate that way.

It does not need to circulate. In fact, in the vans that have a rear heater core circuit, the factory installed a vacuum-powered shut off valve on the supply-side of the heater core hoses that only engaged when the driver flipped on his Air Conditioning.

To enhance my front air conditioning, I installed one of these small 5/8" shut off valves in the supply line to my front heater core:

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It has lasted for over three years here in California without any issues. I recommend it, because bigger valves tend to take up too much space in the engine bay. And for the times I go up in the mountains, I just pull over, turn the valve, and head out on my way.

 

[79jasper]

Anyone got a pic of exactly which vacuum line to tee into?

There's only one over there.

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