I fixed my poor A/C performance
I just did this today to my 2004 Ford F 150, used a 3/4 ball valve. A/C is much cooler, and takes less time to get cold. I figure once a week or maybe more I will open the valve and let coolant flow through the heater core to stop corrosion. I eventually want to get it operated by vaccum or on a switch. Anyone know find links to a 3/4 electrically opened valve?
So guys...what size is the hose? At the outset of this thread a 1/2" ball valve and 1/2" nipple was used. At the end of the thread I see that a 3/4 ball valve was used. Also, I see mention of a heater specific valve with 'barbed' ends on built-in nipples. Do y'all have part numbers/source info for this mod? Thanks!
I just checked mine today coming in to work. AC max 46 deg F coming out of the vents. And on normal it was about 48 deg F. I'm going to clamp off the hose and test it again with the flow cut off to the heater core and see how much of a difference there is. The out come will help me make my mind up on whether to do this mode.
Spoongooner says it made a 10 degree difference in his install. Let us know what improvement you get. How will you 'clamp' off the inlet hose to ensure that no hot H2O/coolant in flowing thru the heater core. Also does anyone know hose size etc.? Thanks...
So guys...what size is the hose? At the outset of this thread a 1/2" ball valve and 1/2" nipple was used. At the end of the thread I see that a 3/4 ball valve was used. Also, I see mention of a heater specific valve with 'barbed' ends on built-in nipples. Do y'all have part numbers/source info for this mod? Thanks! 

I just checked mine today coming in to work. AC max 46 deg F coming out of the vents. And on normal it was about 48 deg F. I'm going to clamp off the hose and test it again with the flow cut off to the heater core and see how much of a difference there is. The out come will help me make my mind up on whether to do this mode.
I think that's a great idea! We need a few more people to do this "test", and report back to us. If all the testers agree that it drops the temp by X degrees, then it may be worth it. But I'm skeptical of chopping one of my lines without positive feedback from several people... Plus, as was mentioned earlier, could this mod contribute to any potential side-effects down the road, such as corrosion of the heater core? Would there be a need of opening the valve every so often? What if I forgot to open it for, say, 9 months? What would happen?
I guess I just like to be safe rather than sorry. OTOH, cooler AC always sounds good, especially when it's 105 degrees out (like right now).
What I'd REALLY be interested in is seeing a detailed write-up on the installation/connection of a vacuum controlled bypass valve. I think someone mentioned doing it on the Superduties, but I'd like some detailed info on the F150 platform.
I've been turning the hardware stores upside down looking for an alternative to the ball valve. I've had no luck.
I wished the OP would post up the info he had on the "CAT valve" he replaced the ball valve with! My plan is to install something right after the Tstat housing. Add a piece of 1 - 2 x 3/4 inch hose to the housing next install whatever valve I can find, then attatch the original uncut heater hose the the other side of the valve. That way if some warranty work comes up I can just remove the valve and be back to stock.
So any idead on an alternative valve?
I wished the OP would post up the info he had on the "CAT valve" he replaced the ball valve with! My plan is to install something right after the Tstat housing. Add a piece of 1 - 2 x 3/4 inch hose to the housing next install whatever valve I can find, then attatch the original uncut heater hose the the other side of the valve. That way if some warranty work comes up I can just remove the valve and be back to stock.
So any idead on an alternative valve?
Being a pipefitter by trade,for 26 years now,I think a CBV would be a good choice..it even has P/T plugs to check the pressure and temperature.Or,a PRV would also work.The only drawback on a PRV is you can't always get it shut 100%!
Go to Autozone and get PN 5968, Ready Aire Heater Control Valve (2 port) or PN 5954 Ready Aire Heater Control Valve (4 port).
You'll also need a vacuum line "tee" to splice into your recirculate air control valve. Run the vacuum from the recirc valve to your heater control valve. This will shut off the heat to the heater core when the AC is on MAX/Recirc.
Edit: FWIW,
The A/C's "radiator" in front of the engine radiator is called a condenser and the "cold" part of the AC in the cab is called the evaporator. They are in no way connected to the radiator and/or heater core.
You'll also need a vacuum line "tee" to splice into your recirculate air control valve. Run the vacuum from the recirc valve to your heater control valve. This will shut off the heat to the heater core when the AC is on MAX/Recirc.
Edit: FWIW,
The A/C's "radiator" in front of the engine radiator is called a condenser and the "cold" part of the AC in the cab is called the evaporator. They are in no way connected to the radiator and/or heater core.
I have no idea if this would work, but, could you just not shut the ball valve all the way? This would allow some coolant flow, hopefully preventing corrosion, yet maybe yielding a 5-7 degree cooling effect?
I just finished this mod, my truck is a black 2005 supercrew. AZ is not the best place to have a black truck with black leather. The air seems much cooler but not as much air flow. I used and 3/8" nipple and ball valve. No complaints yet. Ill open the valve probably once a week or so. Ill test the temps tomorrow.
Last edited by chris116c; Jun 25, 2008 at 02:41 PM.



