a buddy of mine just got back from a trip to san diego. he has a 95 ranger with a 4 cylinder. the trip was from sacramento to san diego and back. the AC worked fine going south. the next day, the AC was Inoperative. he paid 135 bucks to small shop that said it needed a recharge. on the return trip, the AC never got as cold as it was, and 3/4 into the return trip, it blew hot air. any advice i can give him? thanks

 

Did that shop bother to check for a leak? Assuming it's a charge issue, tell your buddy to look at the lines at the connections for traces of oil. If there is a bad leak, oil will be in the vicinity of it. Does the clutch on the compressor engage?

 

Yeah, sounds like a leak to me too. Since it's a 95, it should be 134a. If possible, park the truck in a dark place (make sure it's well ventilated) and take a black light over it. Assuming that the oil in it is newer stuff, it should react to the light. If it's a small leak, you can get away with a leak stop can. Then take it back to an ac place (or do it yourself) and get a vacuum pulled on it and leave it for a day, then check it to see if it maintained it's integrity. If it holds its vacuum, then you can have them charge it.


As Bill said, does the compressor engage??

 

he just told me that his AC clutch is not engaging. he just may have paid for a re-charge that he didn't need. where should i send him? Wrecking yard, autozone?
thanks

 

You need to put direct power to the clutch and see if it comes on,it could just be a charge pressure sensor or a temp sensor.just for a second though,if all the freon leeked out the compressor wont come on because of the pressure shut-off switch,but this will tell you that the compressor does come on .

 

thanks guys, i'll pass this thread along to him.

 

Don't use "stop leak" it would be better to repair any leaks and replace the accumulator. The A/C system will work better if done correctly.

 

Please don't use stop leak or that dye stuff. I've seen examples of both of them cause problems with the orifice tube (plugging). If he for some reason cannot see a trace of oil near a connection, pressurize the system with nitrogen (no, don't use air, it's got moisture in it) and use some dish soap mixed with water applied to each connection to look for the leak. Bubbles will indicate the leak. Do NOT run the system with the nitrogen in it. I am, of course, assuming that he's lost his charge and that's the reason for the clutch not engaging. You can begin by hooking up a gauge and taking a reading without the engine running. The pressure should be roughly the same as the ambient temperature.

BTW, for the charge to have been lost so quickly, there should be traces of oil at the leak source. After looking at the connections, look carefully at the condenser coil. I've came across two of them where a flying rock had poked a hole in them. Also, check the fittings where the gauge set is connected. Usually they are a schrader valve, just like a bicycle tire. Make sure they are seated correctly and check them with the soapy water. I'm not gonna say why, but some sneaky shops like to loosen them a tad and leave the cap a bit loose, just to make sure you visit them every year or so. Pretty crappy trick in my book.

 

You should be able to turn the middle part of your compressor pulley to tell whether or not the compressor is bad. But you have to turn the middle part, not the actual pulley.

Also, what I was saying about the dye, some (or I thought almost all) new oil's already come with the dye, or am I wrong?

Stan

 

thanks all, i'll pass all this info along as i get it.