Anyone use this valve to bypass the heater core?

Old Air Products - Home of the HURRICANE Heat, Cool, & Defrost A/C System - Heater Valve

 

I just use a valve like this....





Here's another valve setup from here (https://www.dieseltruckresource.com/...k-fine-275575/):

 

Will shutting off the flow of coolant effect the cooling of the 5.9 engines or cause an engine failure?

 

Those valves only block the flow of coolant through the heater core. The engine still has coolant flow.

 

I bought one like in the last picture for $10 and change at O'rileys auto parts. ( I did not see the point of making one from parts at the Home Depot or Lowe's when I could buy one for so cheap) Anyway, O'rileys didn't have one in stock, but got it to me in 2-3 hours free of charge. It was made by Murray and made in the U.S.! NAPA had one by 4 seasons, they wanted $13-$14 plus $8 shipping. To add to that, the NAPA guy said ...pay now and wait 3-4 days!

It was pretty easy to add on. It took a little over 5 minutes after I got my tools organized.

 

Why bypass it. Was it leaking?

 

Can help with the A/C cooling ability since hot coolant isn't flowing through the heater core and heat soaking the HVAC box.