A/C Question

Bad Moose

Bad Moose

Just a pain in the arse
Joined
Oct 18, 2008
Messages
923
Ok, Here we go. 03 f250 king ranch extended cab maroon and tan. Front windows tinted at 35% rear factory 20%.
Checked A/C pressures and they checked ok. Drained system last year and checked orfice tube the screen was clean for the most part but had some aluminum shavings on it. Refilled system and rinsed out condensor. Everything was ok... But on hot days above 90 degrees F the truck does not like to cool unless you have a good amount of air flowing through condensor, ie. moving above 35 mph. So around town it is a little warm in cab till you get moving. Then the cab slowly cools down. Do you think this is normal for a dark colored vehicle? Or am I looking at a new a/c pump? Hate to throw a pump at it if this is considered normal. All I have owned are light colored vehicles. What do you think?
 
Is the heater control valve functioning? Is it closing properly to keep coolant from flowing into the heater core? Also when you drained the system did you put it under vacuum and do a complete evac or what?
 
Pulled vac for 30 minutes then refilled with freon. Forgot to check heater hoses, will do.
 
Is the compressor cycling on and off more than normal? On hot days it really shouldn't be turning off since the pressures will be higher.
 
Not that I can tell. But will try to pay attention to that also. Water draining seem normal for the humidity we are having.
 
Also check to make sure the recirculation door is working. Max A/C recirculates inside air to help get it even cooler than trying to constantly cool down outside air.
 
30 psi low side 320 psi high side Ford pressures always seem higher than what I usually work on. Both heater hoses are at 179 degrees f. My crimp pliers are on another machine stopping the flow of hyd oil right now. I will try to get them on the truck later this week or next weekend. Job pays truck does not. Max A/C was blowing cool air forget to get that temp. Truck running at 1600 rpm. 45 psi low side at idle and 270 psi high side pressures taken after gauges settled.
 
45psi on the low side should equate to 45 degrees from the vents. You might have a blend door allowing the heater core to allow some heat back into the air coming from the vents.
 
i don't want to steal your thread but I'm kind of having the same deal but the defrost blows now too instead of it all coming through the vents when on auto. When on recirc it does get colder but still blows on the windshield also. Which is not normal. any ideas?

When I am on the interstate it will get cool but around town I'm in the same with you just almost seems like something isn't right because it takes forever to cool off. thanks guys!
 
Vacuum pump or you have a vacuum leak in a line or possibly the hubs.
 
Haven't been on for a while. Bought a themometer and drove truck for awhile. It was cooling the air ffrom the vents down to 48 degrees when idling and 50 degrees at 35 to 75 mph and 98 outside temp. I think everything is normal for a dark vehicle. Compared temps to my service truck which is white ad it kicks butt. Found My Ford was blowing colder air. :bang:bang

The wife aand I were comparing it to her car which is auto controlled temp and fan. We don't think about the fan noise in her car because it goes down after a little bit. But when it comes to turning the knob manually fan noise drives us nuts. God, I hate being anal.
 
well i think you guys are missing a big part of your first post

When you said you are moving the a/c seams to work better, it takes air flow over the condensor to make that a/c work right, if you dont have nough air flow you build high head pressure, high head pressure causes the compressor to kick out ect ect, i dont know if your fan should be on more with the a/c but i bet a simple pusher fan in front of the a/c condensor will help a ton. Also used compressed air or at the car wash clean the a/c condensor really good, you would be suprised how much that helps.

50 degrees isnt too bad, but i like to see a/c systems down around 40 degrees or so, ill check out what mine puts out tomorrow its been around 85 for comparison.
 
A test of the A/C should be done with the engine revved up to about 2,000rpm and the A/C should be set to max. If the compressor is shutting off due to high pressure it might be overfilled. Obviously increased airflow over the condensor is always welcomed but a pusher fan would now become a blockage to the radiator and intercooler at highway speeds, not something you want if you are towing something down the road. The sunload on a dark vehicle equates to something like the vehicles air conditioning being similar to a 5 ton chiller for your house. Keep in mind that running the A/C on max doesn't allow as much dwell time for the evaporator to remove as much heat as if it was blowing a through on the low speed setting. However, max A/C will cool the vehicle faster since it exchanges the air at a faster rate.
 
pressure gauges will tell you everything...

He's got 320 psi on the high side, thats way to much, some airflow would drop that alot.
 
No, the system does not seem to be over charged. Pressures were checked at 2000 rpm, fan was not kicking on to pull more air through condenser. This was probally causing the high pressure. Have rinsed cooling package every wash. Learned that last year keeping them clean keeps a/c cooler and truck running better, was suprised at how little dirt made a big difference. As I have stated before the pressures always seem higher on vehicles compared to the machines I work on. Probally because of the fan not kicking on. In my exprience water or fan will drop high side 25 to 50 psi. I think it is operator error of the fans compared to auto fan control in the wife car. 40 degree drop is average 50 would be great but.....
 
50 is tits if you can get it there, im sure rollin down the road its closer to 50.
 
sooo if the ac is blowin on the defrost only it could be vacuum pump, hubs or what? hubs are new and lines are zip tied tight. Am I lookin at a vacuum pump? is that warranty work for a 90k motor? whatr should I test? and how? help please cause the wife wants to drop it off at the dealer and I aint got the cash for that!!
 
Not warranty at 90k. The pump is about 125 dollars and is held in by 2 10mm bolts.
 
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