comment Made the AC even colder!

[CHPMustang]

About a week ago I had the hood up looking for something to do that would better the performance of the Air Conditioning on the Excursion which many X owners know I'm always in pursuit of

Typically I shut down the front heater core every May(before we hit the 90's) and looking on the results of that mod I went ahead and looked at the possibilities of doing the same for the rear heater core(yes Excursions have 2 of em plus 2 evaporators)

I located the plumbing in the engine area that leads to the rear,cut off the thick aluminum crimps,capped off the quick discos that lead to the rear HC and then used a 3/4" ID straight coupler with a pair of worm gear clamps to connect the two coolant lines together.While the straight coupler works fine I'd like to replace it with a 180 degree or U shaped coupler to keep the coolant lines in their original orientation as if their were connected stock.

Environmental conditions and results

• 
  *90-91 degrees outside air temp
  *70% humidity
  *Sunny and Clear
  
  *37 degrees front vents @ fan speed #3, rear fan speed #1(low)
  *Freeway at 65mph
  *42/43 degrees at idle while kids run into 7-11 for Slurpees

From the initial observations compared to 2007 in the same weather conditions there's an easy 4-5 degree drop at freeway speeds,while idling at 7-11 it typically would be in the low to mid 50's but with the rear reroute in place I'll be comfortable saying it lowered around 10 degrees which is a huge drop.

I was making plans to have the AC fully serviced but since the rear mod has been done I don't think at this time servicing is required.

The results from this mod was on our Excursion so your numbers may vary with other trucks.

I'll get some pics up.

 

[spindrift]

That's a very cool idea, Bill.

Yeah, I know, the kids say I'm the only one that laughs at my jokes.

 

[NASCAR Mike]

I have never had a cooling problem with my 05X. Having lived in Daytona Beach FL and now Richmond VA my X has seen plenty of heat.

Is it possible the 6.0 engines have a bigger AC condenser up front and thus able to dissipate more heat?

Does your 7.3 have a recirculating feature so you are cooling interior air instead of trying to cool hot outside air?

Have you ever cleaned the coils on your condenser? I bought some cooling fin cleaner from a local air conditioning shop. It's very acidic (wear gloves) but it dissolves road grime, dirt and bugs - things that prevent air from moving through your condenser.

 

[CHPMustang]

Ice cubes!

All Excursion AC systems work to provide a "basic" cool air and nothing more but that's not enough for me which is why I have from day 1 research ways to improve upon how the truck came from the assembly line and this is the same for the SuperDuty trucks. From what I gather that if the vent temps are 30 degrees lower than the outside ambient air the system is sufficient,well I've never been satisfied with that standard,many Excursion owners that have known me for years are well aware of CHP's expectancies

I'll have to cross reference the condensor part numbers between the 6.0 and 7.3L but I believe they are the same unit.
Yes all Excursions and Superduties come with the "MAX AIR" selection for recirculation.

The condensor coils get cleaned at least twice a year by me,it may be overkill but I know it's clear all the time,I hit the coils up with Simple Green or Oil Eater(depends on what I have)
I also clean the front evaporator once a year with a coil cleaner from Kool-it.

Just to note my original post,I was stating an improvement upon the cooling system and not a repair if that makes any sense

At this point I don't think I can drop the temps any further below 37 degrees running front and rear units simultaneously short of installing a second compressor

Temps are verified by a Digital Probe Thermometer placed in the right center vent.

 

[bushpilot]

dang im seeing drops of 45 - 50 degrees over ambient outside temps (switch on max a/c full fan speed)
maybe i need a new thermometer....

 

[NASCAR Mike]

Have you tried installing synthetic R134A? They claim to be cooler than regular 134a.

At what temp should you be worried that your coil will freeze up?

 

[CHPMustang]

dang im seeing drops of 45 - 50 degrees over ambient outside temps (switch on max a/c full fan speed)
maybe i need a new thermometer....

I expect 45-50 degree drop in the SuperDuties at 90-100 degree ambient temps but that's not enough for me. Maybe the thermo just needs a new battery

How much of the cold plumbing is exposed under the 6.0 hood bush? Have you installed the coolant shutoff valve also?

 

[CHPMustang]

Have you tried installing synthetic R134A? They claim to be cooler than regular 134a.

At what temp should you be worried that your coil will freeze up?

I know my 90 5.0 at 33 degrees(on R12) starts to freeze up on MAX setting which would be close to what the R134's should do.

How's the cost of the synthetic compare to the standard R134?

We're anticipating 100+ degree ambient temps today.

 

[bushpilot]

I expect 45-50 degree drop in the SuperDuties at 90-100 degree ambient temps but that's not enough for me. Maybe the thermo just needs a new battery

How much of the cold plumbing is exposed under the 6.0 hood bush? Have you installed the coolant shutoff valve also?

1st my thermometer is mechanical (i will compare it against my digital one
and my multimeter)

no coolant shut off valve...as i understand it, and VISUAL INSPECTION
confirms, that i am not in need of a coolant shut off valve on my model
year (unlike the pre-2004 units and the current 2008).

I have considered installing a ball valve just the same though, and may still.

I agree at the duct/outlet 50degree drops on 100 degree day are not as
much as I would prefer...had the dog in the truck and i kept rollin' down
the window for her enjoyment (while i was sweating my arse off)

you gotta see a full blown Old English Sheep dog w/ 'er head out the window
at 40mph to appreciate why i do it.

I have not tried the r134a...didnt know anything 'bout it.

 

[CHPMustang]

Isn't the heater core and evaporator within the same housing on the 6.0's?

If you choose to do a ball valve make sure it doesn't create a hot spot as I've read that to cause a cylinder head to crack or something along those lines.

The synthetic R134 I'd like to check out.