Faster you go, the cooler the AC

[stamp11127]

It is help - static pressure let's you know if the system is charged properly. Running pressures after the static pressure is known indicates system efficiency and any component issues.

 

[Hugh Janus]

My guess is that it is time for a recharge. If you don't have guages, or can't borrow them, take it to a shop.

 

[stamp11127]

Hugh, it is possible that it is low on refrigerant. It could also be at the correct charge and have compressor issues. He won't know for sure until he gets the pressure readings - if he does. If it is low then there is a leak, depending on how bad it is a recharge could last a long time or vent in a few minutes.

One of the failure points are the two service ports. I make a habit of changing them when I do any ac work. For around $12 a set it is worth the cost compared to the extra time if they leak after a recharge.

Wait until you run across the new 1234yf refrigerant @$60 per pound. A 10 lb bottle is around $600 vs a 30lb bottle of 134a is @$130. Ouch!

 

[DeathMechanic]

I agree with "stamp" on checking the pressures. I have a 2004 that is cooling GREAT at higher engine speeds but, sitting at a stop, it warms up. From past experience I STRONGLY suspect the compressor. If the compressor cycles fast at idle, the freon is probably low (which means you have a leak). Other than that, older compressors just get to where they can't create the pressures at low engine speeds. Just an old Ford tech, with 20 years experience, giving you his two cents. Most people don't have pressure gauges, but you can see if it's cycling fast. The rear A/C sounds like it is the temp blend door actuator.

 

[Hugh Janus]

All systems "leak", some older ones just need a recharge every two years.