AC Pressure High before filled to capacity

[rashaunny]

TLDR: 33oz Capacity. Filled approx 22oz. Has Aux AC in Rear. High 200 Low 45 so I stopped filling. Filling took a very long time. AC is cool not cold. $150k miles. Clogged Condenser, Expansion? Is the Rear AC tied to the front or can I check the rear somehow too... Thanks!!!



Only filled about 22oz including the pos Walmart UV can which sprayed dye all over and over can of AC Pro High Mileage 12oz.

Compressor and clutch are engaging. There is an oil leak from PS that sprayed everywhere so I removed clutch to check and it was intact just cleaned it up.

Checked for leaks via Vacuum pump and vape to see if it may suck any up and didn't discover anything running the top lines and under the compressor.

When it is off they balance out so 110psi on Low and High (See Second Gauge Pic). This is how it's supposed to be; correct?

VEHICLE: 2009 Expedition XLT/SSV police( I assume bc some parts aren't the same and I bought it from police dept some years ago)

 

[twodollars]

What's ambient temp? Those numbers seem ok for about 60 f. Guessing it's hotter than that. Look for a pressure chart and that will help. Bet it needs the extra 10oz. And I'd stay away from the magic additives and sealers. And verify electric fan is on of so equipped

 

[rashaunny]

What's ambient temp? Those numbers seem ok for about 60 f. Guessing it's hotter than that. Look for a pressure chart and that will help. Bet it needs the extra 10oz. And I'd stay away from the magic additives and sealers. And verify electric fan is on of so equipped

Thank you very much. It was about 70deg but I thought above 170 high was bad

 

[GaryH]

What I'm seeing in your photo of the gauges is Low side: 110 High side: 110. Low side is way to high, high side is way too low.

When your vehicle’s air conditioning (AC) system behaves unusually, such as having high low-side pressure and low high-side pressure, several factors could be at play.

1. Defective Condenser Fan:
   • The condenser fan plays a crucial role in cooling the refrigerant. If it becomes damaged or blocked by debris, airflow through the condenser diminishes.
   • Reduced airflow leads to higher pressures on the low side, which can eventually cause damage, including evaporator coil leaks.
   • Solution: Inspect the condenser fan for damage or obstructions. If necessary, replace it.
2. Overcharged AC System:
   • An overcharged AC system can result in high pressures even when the engine is off.
   • Overcharging occurs due to excess refrigerant or an excessive amount of oil.
   • Solution: To resolve this, you’ll need to release some of the pressure. It’s best to have a mechanic handle this.

• If the low side pressure is too high and the high side pressure is too low, the compressor may be the culprit.
• Other components that could contribute to this issue include the dryer, expansion valve, or AC pressure switch.
• The dryer removes moisture from the refrigerant. If it fails, moisture remains, affecting pressure levels.
• The expansion valve can become clogged or defective, impacting refrigerant temperature and pressure.
• The AC pressure switch regulates refrigerant flow through the compressor. Sensor failures can cause imbalanced pressures.
• Solution: Inspect these components and address any issues accordingly.

 

[max78]

The gauges show 110 and 110 approx. . . That would mean you compressor is not running, not turning, is beyond worn out, TXV on front and rear is stuck wide open. . . .

I would double triple check that the compressor is even engaged.

 

[rashaunny]

@GaryH @max78
My apologies I updated my pics. The 110/110 was with the vehicle off. It was my understanding that they equal even the system is off bc the Pressure switch disengages. Is this False?

 

[twodollars]

Your correct, pressure should equalize across the system with engine off. Must apologize I never looked at your Pic, just went with pressures listed in your post

 

[max78]

The pressure is not too bad, but the fact you didnt get to your rated capacity makes me think that you might have a condenser issue. It sounds like the refrigerant is not being cooled, causing pressure to be higher than they should.

Spray the condenser (in front of the radiator) with a hose gently and see if you get any temperature change at the vent with the AC running on max.

If you do you could have a poor airflow, or the condenser is clogged internally or externally.

 

[Motorcity muscle]

You’re still low on refrigerant, you state it took forever to fill. Engine at idle needs more airflow to keep condenser in normal range. Set AC to max, front and rear, keep idle up and charge by weight. Then can be diagnosed if there’s a problem

 

[purevw]

What I'm seeing in your photo of the gauges is Low side: 110 High side: 110. Low side is way to high, high side is way too low.

When your vehicle’s air conditioning (AC) system behaves unusually, such as having high low-side pressure and low high-side pressure, several factors could be at play.

1. Defective Condenser Fan:
   • The condenser fan plays a crucial role in cooling the refrigerant. If it becomes damaged or blocked by debris, airflow through the condenser diminishes.
   • Reduced airflow leads to higher pressures on the low side, which can eventually cause damage, including evaporator coil leaks.
   • Solution: Inspect the condenser fan for damage or obstructions. If necessary, replace it.
2. Overcharged AC System:
   • An overcharged AC system can result in high pressures even when the engine is off.
   • Overcharging occurs due to excess refrigerant or an excessive amount of oil.
   • Solution: To resolve this, you’ll need to release some of the pressure. It’s best to have a mechanic handle this.

• If the low side pressure is too high and the high side pressure is too low, the compressor may be the culprit.
• Other components that could contribute to this issue include the dryer, expansion valve, or AC pressure switch.
• The dryer removes moisture from the refrigerant. If it fails, moisture remains, affecting pressure levels.
• The expansion valve can become clogged or defective, impacting refrigerant temperature and pressure.
• The AC pressure switch regulates refrigerant flow through the compressor. Sensor failures can cause imbalanced pressures.
• Solution: Inspect these components and address any issues accordingly.

The poster stated that when the AC was off, both balanced out at 110psi, which is what his photo demonstrates.