Heater core bypass?

[Bigpaul13]

Hi guys,

I was doing some reading on the 5th Gen forums that guys are bypassing their heater cores so they get better performance from their ac (well same performance but colder air). Has anyone done this on their 4th Gen? It's starting to get warm here and while my truck blows cold air, it's not as cold as I would like.

I have some hose pinchers coming so I can try it temporarily but just curious if someone has done it already.

Thanks,
Paul

 

[Burla]

Do you have the thread for this in 5 gen? I don't see how removing HC will make AC colder, and then obviously you would have no heater when it's cold. I will keep an open mind, thanks

 

[Wild one]

I'm like Burla,got a link to the thread. I'd think if you wanted something to shut of the flow of coolant to the core,one of the old style cable operated inline shut off valves would be the way to go.Run the cable inside so you can manually close or open it whenever you wanted.It wasn't uncommon for cars of yesteryear to have a valve inline in the heater hoses that was cable operated from the heater controls on the dash.

 

[Bigpaul13]

Do you have the thread for this in 5 gen? I don't see how removing HC will make AC colder, and then obviously you would have no heater when it's cold. I will keep an open mind, thanks

Hey Burla and Wild one,

I found it through google and is on another ram forum. If it's cool to link it, I will.

Essentially they have found by reducing or stopping the coolant flow though the heater core with a valve or hose pinchers, the temp from the vents decreases. So on full blast ac, they get something like 8 degree colder air.

It appears to be a bigger issue on the 5th Gens (or was I don't have one) but I've always been disappointed with the ac in my 2017 1500. Today when it was about 70 degrees out, I got about 46 from the vents on full blown ac. So it's not bad I'm just used to colder. These guys are getting similar Temps and then drop to high 30s with the bypass.

 

[Wild one]

Hey Burla and Wild one,

I found it through google and is on another ram forum. If it's cool to link it, I will.

Essentially they have found by reducing or stopping the coolant flow though the heater core with a valve or hose pinchers, the temp from the vents decreases. So on full blast ac, they get something like 8 degree colder air.

It appears to be a bigger issue on the 5th Gens (or was I don't have one) but I've always been disappointed with the ac in my 2017 1500. Today when it was about 70 degrees out, I got about 46 from the vents on full blown ac. So it's not bad I'm just used to colder. These guys are getting similar Temps and then drop to high 30s with the bypass.

I'd believe it BP. Shutting the coolant flow off to the heater core was very common on some of the older cars.One of these would be easy enough to plumb in and install and run the cable inside for operation.

https://www.napaonline.com/en/p/BK_6601271

 

[Wild one]

This one is even Dodge specific,and I think is a bypass style valve.

https://partsavatar.ca/1976-dodge-r...OEBdAw_ows_kpHL_YtB7t9Se3q1X3TVQaAiGdEALw_wcB

 

[Bigpaul13]

This one is even Dodge specific,and I think is a bypass style valve.

https://partsavatar.ca/1976-dodge-r...OEBdAw_ows_kpHL_YtB7t9Se3q1X3TVQaAiGdEALw_wcB

Thanks Wild one. I may go that route if I find it's worth bypassing.

 

[Burla]

I miss all my freon ac's from the 80's and early 90's. Man I should have never got rid of that 93 Bronco worst mistake I think I've made.

 

[Wild one]

Thanks Wild one. I may go that route if I find it's worth bypassing.

Just looked at Summits site,they have lots of them,lol

https://www.summitracing.com/search/part-type/heater-valves

 

[Bigpaul13]

Just looked at Summits site,they have lots of them,lol

https://www.summitracing.com/search/part-type/heater-valves

Yea some guys even went with vise grips lol. The how is pretty easy I lm just curious of the results. If there isn't a difference on our trucks, then I'm not adding a possible failure point if it's not needed.

 

[Wild one]

Yea some guys even went with vise grips lol. The how is pretty easy I lm just curious of the results. If there isn't a difference on our trucks, then I'm not adding a possible failure point if it's not needed.

Vise grips are the old school way of getting home if the heater core or one of the heater hoses started leaking,done that trick a few times myself in my younger days,lol.Hose pinchers are a little easier on the hoses though,so if you have them on order i'd wait for them.If you were in southern Alberta I have a few different styles of hose pinch offs you could use,lol. Up here we don't get quite as hot as you guys down south do in the summer,so my A/C is pretty adequate as it is.Keep us updated on how this works out for you though,as you kind of have my curiousity peaked now,lol

 

[Bigpaul13]

Vise grips are the old school way of getting home if the heater core or one of the heater hoses started leaking,done that trick a few times myself in my younger days,lol.Hose pinchers are a little easier on the hoses though,so if you have them on order i'd wait for them.If you were in southern Alberta I have a few different styles of hose pinch offs you could use,lol. Up here we don't get quite as hot as you guys down south do in the summer,so my A/C is pretty adequate as it is.Keep us updated on how this works out for you though,as you kind of have my curiousity peaked now,lol

Will do. I'm in a moderate temp area but I'm hoping if I can get the air a little colder, I won't have to crank the fan as high as I do.

 

[crackerjack1957]

I always used a 1-inch brass ball valve & used whatever size brass fittings I needed to go with.

 

[ripping r]

I always used a 1-inch brass ball valve & used whatever size brass fittings I needed to go with.

These are what is used on a lot of big trucks. i have seen. the ac in those really suck.

 

[Nova John]

I recently bought a shut off valve designed to go in heater hose from a friend of mine. He bought it for Nova hot rod with no air to try to cool it off a bit inside. He had problems with motor running 20 degrees hotter and sold me the valve to put on my 1983 Malibu with 3.8 v6 and over 293,000 miles on it. I converted air over to r22 and it was not a cold. Since the heater still has hot water going through it car took a lot to get it cold. Put the valve in and no changes for me. I was going to do a v8 swap so I put a bigger radiator in it years ago. I shut valve in summer and open it when it gets cold. Works for me but 3.8 doesn't make much heat as a v8 would. Not sure if I would do it on a newer truck.

 

[Wild one]

Will do. I'm in a moderate temp area but I'm hoping if I can get the air a little colder, I won't have to crank the fan as high as I do.

Paul keep an eye on your tranny temps when you do this.The tranny heater and heater core are sort of tied in on these trucks,and i'm curious if this would change the tranny temps any,i can't see it changing them,but still curious,lol
If by chance the tranny temps go down,i'll be copying you,lol

 

[Bigpaul13]

Paul keep an eye on your tranny temps when you do this.The tranny heater and heater core are sort of tied in on these trucks,and i'm curious if this would change the tranny temps any,i can't see it changing them,but still curious,lol
If by chance the tranny temps go down,i'll be copying you,lol

I was reading about that but a quick look under the hood shows the heater core line comes and goes directly to the water pump. I'm still pretty new to these rams but I think that 3 way valve (or whatever sends coolant to the tranny) gets its coolant from another line.

 

[Wild one]

I was reading about that but a quick look under the hood shows the heater core line comes and goes directly to the water pump. I'm still pretty new to these rams but I think that 3 way valve (or whatever sends coolant to the tranny) gets its coolant from another line.

They changed things around a bit on the later trucks,and i'm not sure how they're routed.My 14 still has the frame mounted 3way bypass ,your 17 will be different in that respect.I haven't been under the hood of a newer truck to actually see how they route the coolant to the heater core and the tranny heater on the later 8 speed 4th Gens

 

[CVX20]

Most A/C systems already have a water valve to stop the coolant getting to the heater core when temp control is turned down.I find it kind of hard to believe that these trucks don't already have one.Kind of defeats the purpose when you have hot and cold air in the heater box at the same time.I'd be taking a closer look at the system before bypassing or shutting anything off as it should already do it by itself.

 

[Bigpaul13]

Most A/C systems already have a water valve to stop the coolant getting to the heater core when temp control is turned down.I find it kind of hard to believe that these trucks don't already have one.Kind of defeats the purpose when you have hot and cold air in the heater box at the same time.I'd be taking a closer look at the system before bypassing or shutting anything off as it should already do it by itself.

Unless that valve is buried in the dash, my truck doesn't have one. I'm assuming the hose going to the firewall is connected directly to the heater core. I have two lines straight from the water pump to the firewall. There's definitely no valve in the under the hood.

Also I know from the research I did, the 5th Gens don't have one otherwise all those guys stopping flow to the core wouldn't have the success that they did.

I got my hose pinchers today so Ill try to run a test tomorrow. Anyone know which hose on the water pump is the output and input? I had no luck finding an answer online but I can do the feel test tomorrow.