I guess I'll need to find some valves and give this a try on mine. Seems easier than my other option...

 

oh snap! redneck A/C!! That is way too funny!

 

Do you still have the temp difference from driver to pass side during first part of cool down?

 

having a temp difference from drivers to passenger is going to happen no matter what we do because of the distance the air travels from the blower to the drivers side. My drives side far left vent has very little air coming out of it even on high and there are no obstructions.

 

Here's a link to a vacuum operated vlv that you could just tee into the "max ac" recirc door vacuum line. http://www.dieselsite.com/index.asp?...PROD&ProdID=21

 

Any comments on an increase in engine temp?

 

i have not noticed any real gains in engine temp as of yet. if I do, then I will add the "T" fittings to keep the coolant circulating with the valves closed.

 

Thanks for the reply, thats the one thing that has held me up from doing this mod.

 

Haven't notice any difference in engine temps with the mod.

Also the 3rd gens uses electric motors for the doors, so there's no vacuum actuators.

MikeyB

 

Sorry I forgot it was a third gen thread........

 

WOW!!! holy smokes, what a difference! as i stated above, i did this mod to my 6.7 last night. i was literally at the end of my rope with the poor a/c on this truck. had it at the shop monday, and they added 1/2lb of freon. said everything else was within specs....yeah right. there was absolutely no difference when i got the truck back from them. had to let it cool off all afternoon yesterday, then did the mod last night. i have been in my truck from about 6:45 this morning until 2:00. i don't have a good thermo to test before and after temps, but the difference is amazing. i went from literally thinking of getting rid of the truck, back to loving it. the a/c is the biggest bother i've had with it. and when i went back to the dealer the first time to feel other new trucks, they were all the same...crappy. my 2 superduties would blow you out of the truck in 100+ temps. i'll post some pics this evening and tell you guys what i used for parts in case anyone is interested in this for the 6.7. it's really the same as the 5.9, just adding a couple tee's and an extra hose to carry coolant over to the turbo. looks as though there is a little less room to work on the 6.7 compared to the 5.9, but it's not too bad. totally worth it though.

 

So is there any benefit in adding a bypass to allow coolant to continue to flow from the inlet hose to the outlet hose. I was thinking of setting the valves up so that when you block off the core, the coolant flows through the bypass. Is it worth the extra effort?

 

I would imagine that if you added the "T" fittings you would have to do a valve in the middle to shut off flow so when you do use your heater, it flows like normal.

 

not sure how much of a benefit there is on the 5.9. it may keeps the engine temps down a small bit. you have to do the bypass on the 6.7 to carry coolant to the turbo.

 

hot dang, exactly what i was looking to hear! thanks for being the test mule, mastercaster! im heading to the hardware store in a bit to grab the needed parts for my '01, my dad's '05, and my uncles '06. Guess I will grab another set for my '08 while im there with the addition of 2 5/8" tee's and a 12" section of 5/8" radiator hose, right?