Hello all! I know I am new here but have been reading posts for a year and love the support everyone has given.

I have a 2006 F350 SD that I don't really have much background on. I purchased it right at a year ago from a family where the father and owner passed away. The truck is from Florida and I live in NC. I have put about 10k miles on it in the last year bringing the odometer to 126K miles now. The truck also had a receipt in glove box from a Ford dealership here where it was brought in for AC not cooling well. The notes said cleaned system and corrected vacuum line. No other notes.

Last summer when I purchased truck (11 years old) the AC was not very cold, but cooled a little. I added 3oz of 134a and it just helped a little and make the pressure gauges happy going by Ford specs. This year, on 90F days, the vents blow 80F air. So I get about 10 degree drop give or take.

What I have done and tested so far-

-Removed fan to cab and used camera with light- evaporator and fan are super clean and air flow is great. Blend door, and max AC valve for radiator fluid to heater core work and fully shut off. Using just the fan mode does not add heat. When AC is on and fan set to high, 1200 rpm engine high idle, outside temp is 83F, pipe a few inches past the orifice tube is 65F, pipe coming from condenser is 72F. Low pressure is 38 and high is 260 on gauges.

-Used a water hose and cooled condenser to see if and issue there- no change. Verified engine fan is working and moving air- Yes!! Checked temps on in and out of condenser, 110F and 92F.

-Decided to reclaim refrigerant and pulled out 2lbs and 11oz. (Sticker says use 2lbs and 10oz). Replaced orifice tube with correct red model and purchased Motorcraft part from Ford. Old part was clean and no blockage. Added 2oz of 46 oil and sealed system back up. I vacuumed system down and no leaks, added 2lb 10oz of 134a from a new canister.

-Repeated tests and same result. Any ideas on where to continue trouble shooting? Compressor stays on and pressures are just about perfect. I could tell there was some leak testing dye I saw in sight glass of reclaiming machine.

Thanks again- Logan

 

FYI- This is a diesel 6.0 and that is why I used the red orifice tube for lower RPM and same as what was removed. Single zone basic controls in cab.

 

Logan,
Great write up regarding your problem. Wish I could lend a hand with something else to check out, but looks like you have included everything that I would want to know to troubleshoot. It would appear that you are shooting cooled liquid freon thru your orifice tube, great pressure drop, with the freon expanding into a vapor. Do not know why you are not getting a really good cooling effect. Look forward to someone with a little more experience answering this thread and solving this problem..

PS - On a second look at your numbers, the only not-so-normal item I noticed is your " temps on in and out of condenser, 110F and 92F" . With 260 psi line pressure that line in has to be at least 150F. Other than than, the mystery goes on..

 

 

If it were a clutch gap issue, the pressures would not be correct as the compressor would not be operating (correctly, if at all).

Your low side pressure says that the temperature at that point should be around 40°F. Is it?

What are your evaporator inlet and outlet temperatures? Are you sure about those condenser inlet and outlet temps?

 

One of the coldest auto A/C I've ever seen was on a 1997 Ford Expedition... Temp gauge reading coming out of the duct was mid 30's... You could see your breath.
The 06' Ford Super Duty was not as cold but did have it down to the upper 40's to 50's....
The 2016 Ford is warmer yet... It's doing good to get down in the 50's
Maybe in another few years the A/C will be in the 80's on a hot day.

I don't know why auto A/C is not colder in later model years.

 

New notes- pipe going into the evaporator is not very cold a few inches after the orifice tube still. I have read issues on bad accumulator where desiccant pouch breaks causing system to clog the small oil and liquid refrigerant to be pulled in. If this doesn't work, I will try a new condenser in the event it has a clog. We will see what happens- Parts arrive tomorrow.

 

Usually, if a desiccant bag has ruptured, there will be sand-like debris that makes it through the condenser to the orifice tube. If there was nothing on the O-tube when you pulled it previously, then the bag is not likely to be the issue.

 

I agree but have read of some fixes and kind of want to try... It is a $30 part to replace (not including my time and a couple oz refrigerant and oil I will have to add). Since the main vapor may not have large debris in it being sucked in on top of the open canister, did they not make it back into the system??? I will cut accumulator apart for science and report back after changed.

I see there are tech notes in repair system for this as being a common failure now and lower vent and screen can become clogged when it breaks internally. I also have condenser coming, but want to try parts one at a time just to see what resolves this crazy issue even if more labor. One bad note is that if this is the issue and compressor still works, it may fail shortly after since screen where oil and small amount of liquid refrigerant are picked up is blocked. No oil is no good. Thanks for the help! Let you know Saturday hopefully.

I also checked for a cold spot somewhere on lines and condenser to see if there was a blockage working like the O tube would- Nothing was screaming "problem here" to me. Today was 86F outside. Air on high was 39 low and 271 high side at 1200RPM.

 

Thank you so much for the reply! I do have have condenser for in the morning and what you said makes sense. Can't wait to see what the fix is one part at a time. I know it would be better to replace all parts at once, but just have to see for myself what the issue was. Kind of turned into a game of sorts. Watch the issue be something like a burned out reverse light causing problem.

 

I need to get my more recent pics on this in morning. This is old info but pics of what I'm checking.
New correct orifice tube. (EDIT addition to notes: The one removed was also correct red one and only a small amount of debris on filter)


Truck in refridge recovery.


Air intake of evaporator is clean. I removed blower and used camera with light to check.

 

So today was tons of fun. Sucked the 134a out again. Installed new accumulator. Vacuumed, checked and refilled. I noticed when refilling the system and 134a going in that it was frozen after the orifice tube and system was pumping out cold air! Too bad it still doesn't do that on it's own. 84F outside today. These are the after pics.



Sucked it down again and replaced condenser. You got it.... same damn results and even higher upper pressure. Ahhhhh!!!

At 1200RPM


I am confused. Bad hoses? Bad evaporator? Bad compressor? Bad truck?
-Logan

 

Ok I've been fighting mine. I checked everything I could and it said I needed more freon. Added some high side pressures at 350. Low side I got up to 42. Started at 36 and 250. Still didn't seem to fix it.

Until...

I had disconnected my battery and when .I reconnected it it was cold as hell. Down to 42 degrees with outside at 90.

I think it's the blend door actuator. It's as if the power down reset it. Today in traffic it was kinda warm so I cycled the blend **** for 10 seconds each way. When I killed the truck to get gas I restarted it and it was again. Cold as hell. Like it should .

Disconnect your battery for 10 minutes and reconnect and see if your AC works again.

I'm in the process of looking to see which one I need. I think mine being a single zone it's the actuator on top behide the radio

 

Going back two weeks...
I removed the glove box and verified the blend door is working. I also verified the door is closed with fan pulled out from engine compartment. I put max AC on and vacuum line closes the water line like normal to heater core. I ran just fan mode and no heat is coming out. I think this may be a separate issue especially with temp readings after orifice tube and coming out of evaporator not being cold. For your issue, the blend door motor and nylon gears snapping is common. Who knows. Thanks for the info- I would like to recommend the Ford brand new blend door. After a couple Advance auto ones clicking and failing in a Ford Flex, the new model from Ford that is revised did fix that issue. Your previous pressures on AC seem good, but new readings seem high. I would removed some freon to get it back down if it were me. (I am in no way an expert. Just what I have seen from reading)

-Logan

 

Thanks Logan for the reply. Yes the pressure reasonsr do seem high after and I plan on going to a shop and have them evacuated and filled to the correct level .

I've read some post that had the high side pressure pretty ambiguous. It just seems high now as well.

Keep us posted. I'm intrigued.