a/c cooling, but not as good as before...

[mikeinaustin]

vehicle is a 2002 toyota tundra v8 (140k miles)

At least that is what i feel and everyone else in the family as well. However, i hooked up a gauge to the low pressure side and the pressure reading was dead perfect based on the ambiant air temperature.

Assuming that is true, what else could cause the system to cool, but not as well as before? In my humble opinion, i would say cooling is at least 25%-33% worse than before.

fyi, the ac system has never been serviced.

 

[Chris142]

The low side guage is pretty much useless! I have no idea why they put it on some cans or Refrigerant. It's just a gimmic.

I can tell you if your system is low with high side pressures and ambient temp though.

 

[mikered30]

Try gently rinsing your condenser and does this model have a cabin air filter?

 

[Torino]

Yes, Chris 142 has it nailed. The high side reading is most important. Further, if the system is SLIGHTLY low on refigerant, it will cool better. John--Las Vegas.

 

[rshaw125]

Take a thermometer and see what it is actually putting out through the dash.

 

[artbuc]

Originally Posted By: rshaw125
Take a thermometer and see what it is actually putting out through the dash.


What should the temp be leaving the dash?

 

[mechtech2]

It is the high side that is more temperature dependent.
The low side has cycling switches and cycles at fixed pressures.
Your system may be low or high - who knows?
Read up a lot and try again, or get it checked by pros.

 

[mechanicx]

They put very little refrigerant in A/C systems nowadays. So slowly over time some of it can leak out and then there is not enough refrigerant for optimum performance. Like was mentioned you would need the high side numbers to get a sense of whether the system was working right. You might not have a leak that needs fixed, and an evacuate and full recharge might get the system working good.

 

[rshaw125]

The temp should be in the 40's F. My old mini van can get it down to 39 degrees F. My Ford Explorer 46 degrees F. when it's about 80-85 degrees f out.

 

[artbuc]

Originally Posted By: rshaw125
The temp should be in the 40's F. My old mini van can get it down to 39 degrees F. My Ford Explorer 46 degrees F. when it's about 80-85 degrees f out.


On recirculated or fresh air?

 

[Vizzy]

Good question.

I THINK it is using recirculate. Anyone?

 

[mikered30]

Recirculated air on the center vent at 2K RPM.

 

[mechtech2]

Try a static test. This is a valuable quick test.
After a good long cold rest, check the low pressure - it will then be the same as the high pressure [stabilized/equalized]
At about 75-80 deg ambient temps, the reading should be about 80.
This will show that you have approx the right amount in the system.
Running pressure checks are added to this information base.

 

[rshaw125]

On Recir. What temps did you get? I always check mine with a thermometer first. Much easier than attaching the gauges. Then when I am pretty certain I need freon I attached the gauges and add freon all at the same time.