mastercaster

precisely what i was thinking.

Dan_K

I'm going to do the return line as well. I did notice slightly colder A/C but I'm still running it on higher speeds to keep up with the size of the cab.
My wifes Infiniti only needs to run on low setting once the cabin is cooled off. 100* heat and it will freeze you right out of the car. It is also dual control and lets you select what temp you want, so I can put my side on 68* and hers on 72*, run it on low and there is no blower noise or high air movement. It just makes an ambiant temp in the car. I'd love to have the truck react like this as it is very comfortable.

Mr Bee

I would also like to throw out there that the constant flow of coolant keeps things dry and mold/fungus will not grow. On my 99.5 ford SD I did this mod and a month later my truck smelled like old laundry. Had to use an anti fungal foam
to kill the smell....The mod works but not without side effects.

CrazyCooter

The 5/8 valve from NAPA is 660-1414. $17

MikeyB

I have this issue even without the mod. That's why I try not to run the AC in recirc to much.

MikeyB

HOHN

Here's how to prevent and how to treat the stinky A/C problem:

PREVENT:
-- When you've been running your A/C wide open for a length of time, you need to warm the ductwork back up before you shut off the truck. So when you park, just turn the temp control to max heat while still on A/C (oops, you did the valve mod, didn't you). The mold and mildew comes because the ducts are so cold that when you shut off the truck, humidity condenses and you get moisture in the duct work, leading to mold and mildew. Running hot dry air through them just before you shut the truck off will warm up the ducts and prevent condensation, and thus the stink as well.

FIX:

-- Get a couple cans of disinfecting spray like Lysol or Clorox and in a scent you can tolerate. Then fire up the truck, crank the fan up on high speed (but do NOT put the mode on "Max"-- you need to be drawing in outside air). Roll down the windows. Take a can and empty it into the air intakes at the base of the windshield (wiper cowl area). After a can or two leave the fan on with the engine running until all the liquid is evaporated.

This usually works, but sometimes you have to do it more than once. Make sure you turn on the A/C when you do this, but set the heat up to middle or higher (or if you did the valve mod, open the valves and let coolant flow).

JMO

MikeyB

Thanks for the tip Hohn.

Living in the tropic zone is always an issue with mold in the evaporator core. The trick is to dry out the evaporator before shutting down. Best method is leaving the vents set to outside air, blower to max speed and turning off the AC a few minutes before parking.
Also I use a chemical from Interdynamics that works pretty good when it gets really nasty.

MikeyB

jjoiner

I've already done this mod by blocking off just the supply line off the head. Would the cooling system benefit any if you went ahead and installed valves, "T"'s and a piece of hose connecting the supply and return lines just like they did on the 6.7's thus isolating the heater core but still having a continous loop cooling system? Or is this just over doing things?

tacohat

The only solution that I found so far would be something like the following.
Note: Any regular 12 vdc solenoid valve that I found only had either a 150*F or 180*F rating, therefore not able to handle the higher engine temperatures of 210*F to 220*F.

http://www.valvestore.com/prodinfo.asp?number=542703

Voltage: 12VDC (2.4 amps max)
Pipe Size: 3/8" NPT female
Port Size: Full Port, orifice 0.39 inches, Cv 7
Pressure (Max): 600 PSI WOG
Valve Temperature: 300º F maximum
Actuator Temperature: 0 to 150º F
Valve Body: Brass
Ball: Chrome plated brass ball
Stem Seals: PTFE (Teflon) with double FKM (viton) O-rings
Ball Seats: PTFE (Teflon) energized with FKM (viton) O-ring backing
Cycle Time: 3 seconds per 90º rotation
Duty Cycle: 75% duty cycle
Enclosure: Cast aluminum, polyester powder coating
Enclosure Protection: NEMA 4 water and dust tight
Electrical Connection: 1/2" NPT female conduit
Over-load Protection: Thermal overload
Dimensions: 7"H x 5.63"W, 2.64" valve end to end
Weight: 5.8 pounds

XLR8R

Big & $$$!

There are better choices than that, but any solenoid valve rated for the application is gonna be high...

tacohat

There are other choices available than an electric valve.
Check out the following part numbers from Napa:

BK 6601140
BK 6601141

These are both cable operated (push/pull) 5/8" valves.
To use these, you would have to run a cable inside the cab and use something like a choke cable to operate the valve. Cost = about $20 plus the cost of the cable. You might run the cable through the firewall below the steering wheel and mount the push/pull mechanism out of sight.

These type of valves were used on older vehicles that didn't come with air conditioning.

cbrahs

I have too many things in the cab and don't want a couple cables to deal with. I have more XLR8R gauge plates and gauges to install! lol

cbrahs

you won't be overdoing things by installing a "T" to keep the fluid circulating thru the OEM heater ports but I would do a valve on the return side so it does not create pressure on the back side of the heater core.

cbrahs

that thing looks HUGE plus weighs nearly 6lbs!

just use about 35 seconds of energy and get the manual valves to operate!

jjoiner

Thanks. I decided not to do the bypass but did install a second valve on the return line today.