A/C is warm

[juan214]

So I started to address this A/C issue last year figured I would continue with it this year.

Curently A/C blows at vent a constant 78 degrees. Some what cool depending on the day. Went to check the level this past week end to see if the system emptied out again. When I took the cap off there was some UV dye at valve and some pressure releive, figured that it was no big deal. I know someone will say use a manifold set to check it. I just wanted to do a quick check to see if it leak out as it has for years. Anyway it didn't leak out so the work I did last summer went well. It was 85 degrees out so I should be at 55/379 at most. System was overcharged so I had some purged out now its at max 55/379 and still blows 78 degress.

99 Expy EB w/ rear a/c & heat

Last Year it was empty blowing 100 at the vent.

• Got a loaner Vacuum Pump
• Got a loaner Gauge set
• Replaced compressor and clutch (new) w/ .8 oz. oil
• Replaced all the o-rings but two they were up above an exhaust shield
• Replaced PAG oil 3 oz.
• Replaced Expansion Valve
• Replaced Orifice Tube
• Replaced Receiver Drier / Accumulator
• Replaced HP Sensor w/ O-ring
• Replaced R-134A from Walmart

A hour vac, a hour hold, a hour vac. Put in about three ounces PAG oil, 62 oz. or so of R-134a. Put five twelve ounce cans in plus some from a sixth can for around 62 like the label said. Also added a little UV dye. Filled the compressor up to compensated for the dryer replacement and added some more oil through the line for what leaked out under the truck when I changed the o-rings. Guages read good on vac got down to -30 and stayed there. Got to 50s when filling the system.

Result: Last year got it down to 58 - 60 degrees at the vent this year it's at 78 degress at vent.

Any sugestions are welcomed.

Thanks In advance guys

 

[stamp11127]

Refrigeration is based on pressures and temps. We need to know the low & high side pressures after running for 10 minutes. And also the ambient temp at the same time.
If you have pressure in either cap when you remove it the service port is leaking.

Did you use AcPro with sealer from Walmart?

 

[juan214]

Hey Rich,
I pulled the cap before leaving no pressure relief. Let me go and see if I can get a Manifold set.

 

[stamp11127]

Readings need to be taken with the blower on high, recirc mode & temp setting on cold.

If the readings stay at 55/379 the system is most likely overcharged or the cooling fan isn't working, radiator and condenser are loaded with trash. The pressures you have are way too high. We start worrying if the high side pressure gets past 325 on the semi's. Over 400 and the safety on the compressor will lift to avoid going "bang".

You can still be overcharged even though the correct amount of refrigerant is loaded. If oil is added beyond the specified amount the refrigerant capacity of the system is reduced.

 

[juan214]

Refrigeration is based on pressures and temps. We need to know the low & high side pressures after running for 10 minutes. And also the ambient temp at the same time.
If you have pressure in either cap when you remove it the service port is leaking.

Did you use AcPro with sealer from Walmart?

• No straight R-134A no sealer when the new parts were installed
• Fresh PAG oil in compressor
• UV dye through fill hose

This in the last can I emptied (not in the truck).

 

[juan214]

As of 6:37 pm
View attachment 31048

Off.

Pressurized.

At Idle.


Clutch is spinning. Truck was driven for 47 minutes to go get the gauges.

 

[ATXMom2]

I have a 2018 XLT Expedition that we purchased August of 2018. The AC was great until recently. It does not always blow cold, sometimes it blows hot sticky air for 10 minutes then blows cold. Other times it never turns cold and then other times it will work great. It is at Covert For for the second time and they are telling me that they cannot duplicate the problem. The AC acts up every other day...they have had my car for 4 days. Very frustrating. At this point I am ready to sell the car. I live in Texas...I need AC!!!

 

[stamp11127]

The high side is good, low side it way too high for my liking.
What does the low side read if you run the rpms up?
What is the accumulator doing as far as temp goes?

The orifice tube may be letting too much refrigerant into the evap or the evap may be clogged and not getting enough airflow through it. The result of either will be higher evap pressure.

Are you seeing any condensate dripping from the lines or the plenum?

Another thing to watch is how fast it equalizes once the system is turned off. If it is very quick the rear txv could be stuck open.

 

[juan214]

The high side is good, low side it way too high for my liking.
What does the low side read if you run the rpms up?

 

[stamp11127]

I would use your reclaiming machine and recover a little of the refrigerant......I can't tell you to blow a hole in the ozone layer if you don't have a machine though.
That will lower both the low and high side pressures.

Here are your capacity amounts:
1998-2002 All Engines w/ Front & Rear AC ... R134a 62.00 PAG 46 11.00oz

How much oil did the compressor manufacture say to add to it?
Above you stated that you added .8oz to the compressor and then 3 oz to the system. Need to determine about how much oil is really in the system.

Did you check the color of the orifice tube to the one you pulled out?

 

[juan214]

The high side is good, low side it way too high for my liking.
What is the accumulator doing as far as temp goes?


Are you seeing any condensate dripping from the lines or the plenum?

Another thing to watch is how fast it equalizes once the system is turned off. If it is very quick the rear txv could be stuck open.

No condensation or dripping. IR Reader says the top of the dryer ranging between 90 - 100 degrees. The line next to battery is cold to the touch but temps is 85 degrees with slight condesation.

 

[juan214]

How much oil did the compressor manufacture say to add to it?

Compressor came with .8 in it went to drain it out nothing came out even turned it. I only added about three ounce from the bottle to replace what may been in the dryer and leaked out during o-ring replacements under the truck.


Did you check the color of the orifice tube to the one you pulled out?

Supplier told me told that the red orifice tube was in the engine bay. i'm pretty sure i matched it. I belive the other did not fit anyway.

 

[juan214]

Another thing to watch is how fast it equalizes once the system is turned off. If it is very quick the rear txv could be stuck open.

After three minutes the system equalized at 75. High side dropped slowly to 100 then jumped up a little then gradual went down to 75.

After an hour its equalizes at 84.

 

[stamp11127]

RockAuto lists a cabin air filter for the 1999. I would have a look at that before proceeding with anything else. If it isn't clogged then I would reduce the system charge slightly.

 

[juan214]

RockAuto lists a cabin air filter for the 1999. I would have a look at that before proceeding with anything else. If it isn't clogged then I would reduce the system charge slightly.

Did that Mod back in September 2016 its in the signature below. The picture is with spotlight on behind it. Can still see through it's not caked up. Brushed it off nothing came off no dust nothing.


While I was there I checked the blend door, it's fine no cracks, not broken, and swings fine. Jiggled it up and down and side to side its in there. I thought maybe the blend door may be stuck or broken.

I took some temps tonight with the filter in and out they are the same. Its 77 degrees out, in the box near blend door it got down to 60 +/- degrees and at the center vents it was 70 tops.

 

[juan214]

Ran truck for 20 minutes and took some temps just now. Its 79 degrees out. At idle a/c on max there is no recirculation that I'm aware of.






Looks like its about 5 pounds over on low side and maybe about 30 over on high?

 

[juan214]

I have a question there is this part of the dash panel under the climate control with vent holes. It was replaced years ago with one without holes could this be part of my issue?

Anyone know what this it is for?


Thinking about taking the dash apart to see what was or is there. Might be connected to this hose I spotted last night, maybe.

 

[stamp11127]

Pressures are still too high. Low should be in the 30's. Make sure the fan clutch is working correctly, if not pressures will be high. If you have a shop fan place it in front of the condensor and see if the high side drops.
I'm also assuming the fan shroud is in place.

 

[juan214]

Pressures are still too high. Low should be in the 30's. Make sure the fan clutch is working correctly, if not pressures will be high. If you have a shop fan place it in front of the condensor and see if the high side drops.
I'm also assuming the fan shroud is in place.

I have been using this chart. Just hit 80 out.

50 and 210 max right?

Fan clutch may be origanal didn't replace it when I did the engine over in 2016

Shroub is in place and intact.

I have a box fan readily available.

 

[stamp11127]

That is the "non New Yorker" r134a chart. I use a different chart that I call the "Jesus" chart. If my wife hasn't said "Jesus it's cold in here" the a.c. isn't working properly. Plus I'm a transplanted New Yorker.....

We have the students under charge, normal charge and over charge a system so they can see and hear any differences between them. When we have low side pressures around 37 psi, vent temp is very close to the pressure reading. Then I have them read the evap with a thermister. Usually the evap is around 10 degrees. I ask them to explain why the condensate isn't freezing with that low of a temp.