Bypassing heater core

Has anyone tried bypassing the heater core during the summertime? Is there a valve already inline? I was helping a friend install a new radiator in an F350. He installed a bypass valve to the heater core. Claimed AC to the cab was much cooler. Thoughts??

 

So, is it like three shut off valves? One on the inlet, one on the outlet and a Tee right before both of them with its own shut off valve?

 

Not sure about the Tundra, but I had a ford product with a heater control valve on just one heater hose. Same vehicle was a damn nightmare with cooling system, cracked thermostat housing, cracked radiator, cracked plastic coolant line, cracked heater control valve. Eventually I bought a lower pressure radiator cap and it seemed to fix it. But always concerning, those who have experience with the plastic thermostat housing know exactly what I am talking about. Famous Ford engineering failure! Probably on purpose for the revenue it would generate.

 

It would just be a ball valve on both the inlet and outlet lines.

 

I think you would basically be creating a few additional potential leak points with that method. Why not just remove the hoses and swap connections around to complete by pass circuits? No valves needed. Spring and Fall make the swap, heater hose is cheap if you need different length.

 

Would you not need the flow? I thought that have to be flowing whether it’s going through the heater core or just looped old school style. We used to do that on our old 60s and 70s rides when the heater core would take a dump.

 

Putting just a ball valve on both sides sounds like a bad idea. That is not a bypass that’s just shut off. When I think of a bypass, I picture something like on the top of a water softener. Either it’s flowing through the unit or flowing around it.

 

A single three-way ball valve would do the job of maintaining the bypass circuit just fine, if it is indeed needed. You don’t need to block both the inlet and outlet of the heater core to stop flow, since we’re not trying to work around a leak here.

 

I just did a quick Google search and apparently there is a inline valve at least on some years, very much similar to my Ford version. Now I will have to get the hood open and investigate a little bit just out of curiosity. Point is, it may already be getting shut off. Maybe I will look into it tomorrow.

 

2mchfun, Thanks. Please let me know what you find.

 

One heater hose is basically tied into the lower radiator hose, the other goes behind the engine between the firewall and the engine so gonna have to get out one of my mirrors and get a better look back there. There is a chance that any valve might be under the dash too. Probably will check Google a bit in the next few days and see what I can learn. Will update when I get more info.

 

I used a vacuum operated bypass valve on my old f250, when I set it to max ac, it shut off the coolant flow to the heater core, but still allowed coolant to cycle through the block.

 

Best I can tell one heater hose connects to the transmission warmer "puck" and the other leads to the water pump, so I assume that if any control valve exists it's under the dash, doubtful though because that would prevent flow through the "puck" which would build heat in the transmission. Maybe hot coolant is meant to flow through the heater core before it's used to cool transmission fluid at the "puck". Basically I am thinking the coolant would be a bit cooler after going through the heater core which would result in some ability to cool the transmission fluid. Quite interesting, now I can see why the "puck" is called warmer/cooler.