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?