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AC thread - 2012 F-150

Pony_Driver

Red Skull Member
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May 25, 2020
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So I don't junk up DMG's thread in Chit Chat, what is going on with my AC?

It worked okay over the summer, but not great. Fast forward to a few weeks ago and I noticed a slight bearing noise under the hood. After looking I saw that the water pump was leaking so I replaced it, the T-stat, the tensioner and the belts (AC has its own). After buttoning it back up I noticed that the cooling fan kicks on HIGH any time the interior fan is on. This is new and did not happen before. I grabbed a new set of gauges and the low side was low, less than 5psi low and the high side was about 325psi. Obviously way out of spec. Bad expansion valve? Blocked orifice tube? Best course of action? Short of buying a manpurse and smacking it real good, best guesses as to what caused the issue? Should I just Rock Auto all of the parts and send it?
 
Research is indicating a likely bad TXV. I will have to check later to see if it ever equalizes.
 
AC threads the day after Christmas ? This is a bad sign for the year to come lol
 
Leadfoot21 said:
AC threads the day after Christmas ? This is a bad sign for the year to come lol
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Only posting because the pressures are fucking with the cooling fans and I want to keep this ride rolling in good shape. It's been solid for me for almost a quarter million miles, I'd like to keep rocking it as it's cheaper than a car payment.


It must be the month for AC's since I replaced a unit at the house two weeks ago. :flipoff2: I have the units for the other system too, just in case it dies. Otherwise it will be installed in the early spring.
 
In these situations it’s nice to have a robinaire machine . Your pressures certainly indicate a blockage but it can be fun to determine what it is . Best thing to do would be evacuate the system and check out the TXV or orifice tube . I’ve seen driers come apart and plug the tube or the TXV many times which can also end up plugging up every single component . Seen TXVs just to bad and be a simple fix etc . But if the orifices tube is blocked typically it’s due to the compressor coming apart and metal shavings clogging it up . At 250k I’d be planning on more than one issue.
 
Leadfoot21 said:
In these situations it’s nice to have a robinaire machine . Your pressures certainly indicate a blockage but it can be fun to determine what it is . Best thing to do would be evacuate the system and check out the TXV or orifice tube . I’ve seen driers come apart and plug the tube or the TXV many times which can also end up plugging up every single component . Seen TXVs just to bad and be a simple fix etc . But if the orifices tube is blocked typically it’s due to the compressor coming apart and metal shavings clogging it up . At 250k I’d be planning on more than one issue.
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Yeah, I don't have one of those and I am afraid of turning it over with a blank check. From what I read there is no orifice tube in this one, just the TXV and drier. Any sure fire way to determine if the dryer is junk? For $36 plus shipping a txv is easy enough to change out. I have a vacuum pump and can recharge the system.
 
Oh yeah, I have a PS turbo coolant leak. That's probably a grand at the dealer.
 
Try the TXV first . If the drier is like the ones I’ve seen you’d see desiccant beads stuck in the TXV
 
I swapped in a new TXV today along with a new fan assembly. Much better but still not fixed 100%. No more screaming fans! Both fans will come on with coolant temps elevated and at least one when the AC is activated. I pulled a vacuum for an hour and let it sit for 20 minutes before charging the system. I was dealing with this while dealing with a sick wife and calls from work. I don't have an exact measurement for how much refrigerant I got in the system, I should have weighed the cans. It will cool a little, but I did not get condensate on the low pressure line. It will work for now and if I have to I'll pay someone to look at it in the spring. Hopefully I can get a day where I'm not pulled in too many directions to properly run through a check ride on it and troubleshoot the whole thing before turning it over. FWIW the old TXV did not have any junk in it.
 
Well, after idling for a while dealing with a downed tree my high speed fans kicked on again. When I got home I put the gauges on the AC system and the high side was a 375psi. :eek: I cracked the valve to bring it down enough to shut the fans down. What else could be the issue? Clogged evaporator? Chooched condenser?

EDIT: High side is too high, the low side is too low.
 
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I do a lot of A/C work and have an A/C machine, if I had a vehicle with the pressures you have I'd change the orfice tube/TXV, condenser, drier, make sure the radiator is clean and air flow through it unobstructed and maybe check the evaporator to make sure it's clean then charge it, after that you A/C will work like the day it's was born.
 
New compressor and condenser, plus the TXV from last week. The condenser had a built in drier. Much better now and the fans don't scream anymore.
 
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