Doesn't make any difference which direction the coolant flows.

Shutting it off is shutting it off.

Don't spend a lot of time over-thinking this.

Pop

 

Thanks Pop!! I wish everyone would stop being so cheap by getting the manual valves at the hardware store , Lowes or Home Depot.......ALL it costs is around $25 bucks to do it right rather you cut the white or red line!

Guys spend a crap load of $$ trying to make their truck faster, but when it comes to a neat, cheap mod like this most seem to cheap out.....

 

what size is the heater line 3/4 .. 1/2 .. or what ?
Thanks

 

I believe its 5/8"...........Just get the Ranger valve, some vac line, cut the red or white line, install and enjoy cooler a/c.

I hate to see people use household stuff (Plumbing/Electrical) used in vehicles!

 

I spent a total of $31.31 for the parts listed (i did 6' of vac hose as I am not sure exactly how much I needed for a nice clean look) and will be doing this mod when I have time to let the truck cool down!! can't wait to see…..errrrr…I mean feel the end results!

 

I installed a vacuum valve to control my Ranger valve. I was trying to cool down the vent air (about four months a year here in Western Oregon the outside air is cool enough if you keep the heater core from getting involved) so as to avoid running the A/C so much. It had little effect on the temperature of the vent air, but really cools down the A/C!

I tapped into the main vacuum source to run my valve, since I wanted it to work in VENT position, too. If I keep the Ranger valve closed, I cannot vary the temperature of the A/C, since there is no hot air to blend. If I open the Ranger valve, the temperature can be controlled normally, but the coldest position isn't nearly as cold as with the valve closed.

The valve and fittings came from two different sellers in China via Ebay. The fittings screw into the valve and swivel so you can position them. They use a 4mm (5/32") nylon tubing, and I bought a "T" and a rubber adapter to transition between the tubing and the fitting on the Ranger valve from NAPA. I mounted the valve by drilling a hole in the panel with the trash bag holder under the cup holder. It is pretty much out of the way, and if I remove the modification in the future it won't show much, and I can always find another trash bag holder.

The valve has a bleed hole so it releases the vacuum in the line to the Ranger valve when you turn it "off."

Pikachu, I have extra valves and fittings, and I can send you a set if you want.





Toggle Valve





Push Lock Fittings

 

is there any possibility i could get a wider angle of this picture so i can see where the line is running to/from and what it is sitting next too? I am pretty sure that its the one by the AC compressor but I want to be 100% sure, thanks!

 

Another satisfied customer! just finished this mod on my early 99 F250. I used the Red hose and it works exactly as expected. Thanks to all who completed this mod and explained how it was done. It was extremely easy, one of the easiest mod I've done. I've done a LOT. Hardest part was fishing the vacuum line thru the firewall.
Great Mod and easy to do. Napa parts totaled $29. I'm the guy who likes to use the vent even in winter. Happy, Happy , Happy.
Ron

 

7/14/2018; Bump back to the top for the summer!!

 

Another maintenance item that may help cool your A/C down a bit is cleaning the evaporator coil. I did up a short video on how to do that which is below.

 

Have never done this but I really need to. Just can't find the time.

 

It really does help. Yesterday I towed our 5th wheel camper in 90 degree heat and high humidity and this was the first time in the four years of ownership of the truck that I had to turn the air conditioner down.

Between the Ranger/Excursion valve and the rejuvenated evaporator I am very happy with the A/C now.

 

After 19 years and 215 k miles, I finally did this mod yesterday. I knew about it but procrastinated until this years SoCal heat became unbearable in my truck.
Prior to this mod, a month ago I took out my one and only shim on AC clutch.
Tips / thoughts about this mod.
1) Buy the Excursion or F series heater valve, that way you only need to cut one heater hose.

2) Buy 7/64" windshield wiper hose or equivalent.

3) Buy an 1/8 " three way T brass. Make sure all tees are 1/8 " and hook up to top red vacuum hose under dash. Also make 3" piece to go in place of where you remove the red prior to installing the tee.

4) buy the electronic vacuum actuator solenoid seen here : https://nostalgicac.com/vacuum-actuator-solenoid.html

and hook up wires utilizing one or more of the available pass through wires near Master cylinder area. This way you can cycle Mod off in the winter or monthly to run some coolant through the heater core. I plan on installing blue lighted switch near the AC control panel for quick knowledge of Modification configuration status.

5) feed the vacuum hose through the empty feed through grommet along side kick panel above carpet Passenger side.

I had a friend help me, and I am still waiting on the electronic vacuum actuator. Took about 2 hours to do the job.

I ran power feed inside loom that exists along hood near windshield.

NOW I want to do the glow plug momentary NAPA switch. Does anyone have the link handy? Thank you all members. I love this FORUM!!

 

Why not just connect to the MAX AC vacuum hose so it only closes when you have the system set to MAX? Then no need for the extra actuator. From what I’ve read it is behind the glove box.

 

Because you still cannot use your vent to obtain cooler outside air. The outside air is heated by the heater core.
Then you need to use AC more often.