not as cool as it once was
 

My 2001 Supercrew needed a little freon this spring. Adding it made it cool, but not like it used to. Gauges show it is still full (both low and high sides) and I can tell the blend door is working (turning the temp knob makes it warmer or cooler) but even all the way to the cold side it is just not as much as it should be. Also it gets warm at idle. In previous years, it still blew cold at idle.

The air switches between defrost/vent/floor quickly so I don't think controls are issue. No visible junk in radiator area. Compress seems to be engaged as usual.

Anyone got advice on where to look next?

freon mixing?
 

Took truck by a recommended AC shop. When I told them that another "service station" had put freon in at the start of year, they said that the other station used things other than R134 and that I needed to have the system drained, pull a vacuum and new, correct R134 installed.

who is telling me the truth?

Hard to say....some of those guyz like to put each other's shops down....

Probaly Bs. We do our own ac work on our farm. R134A is 134A. Everything else uses their own fittings. However, Too much freon will lower performance. So thats actually one of the first things we do. Suck it out, See how much we recover. Vac for an hour and refill. 85% of the time that fixes it.

You could tell him to go ahead, but your only paying if it makes it better. That your not going to pay for his guess. Some shops will do it, some will tell you to pound sand.

Cool
 

Shop did vac and refill. Before turning on high was barely enough not to sweat. Now on hottest day of year i had to turn it down. I am cool and happy