air conditioning quit working

[Jaguar5822]

Hi, a few days ago, my radiator got a hole in it, leaking out most of the coolant. I had to drive it home like it was, pretty hot outside too. I kept an eye on the engine temp guage, the highest it read was 230, no overheating. I have since fixed the hole in the radiator and fluched all the coolant. Before it happened, the AC blew nice and cold, now it blows air that is maybe 2 degrees colder than the air outside, no matter what. I bought some R134A with a pressure guage on it, and when I went to refill, the guage said the pressure was already too high, it read about 105. I had the car running and AC on full blast just like the can says to do. What could be the problem here?

thanks,
James

[AllTheGoodNamesAreGone]

well... the coolent is there..

maybe its the compressor..
or a fuse??

start there
~Billy

[Jaguar5822]

Hey, the compressor still turns on like it's supposed to. The small tube coming from the cooler to the compressor is still cold, but the larger tube that comes out of the compressor to the silver thing where you fill the coolant is warm, The only thing I can think of is somehow the compressor is either blocked up, or it is really heating up the coolant.

James

PS what pressure should I keep the sytem at?

[AllTheGoodNamesAreGone]

I am not too sure about the pressure.. the guage i have is color coded.. It pretty standard from what i remember..

I dont really have any other advice.. sorry..

any other takers?

~Billy

[Jaguar5822]

Nobody has any other ideas? I really don't want to take it to a shop and get reamed for the repair. Could it be like a vacuum line or something? Does anyone know what vacuum lines I should check?

James

[chas]

i have a pretty basic understanding of a/c cooling. i believe the following are true:

the compressors compresses the refrigerant. this heats it. the hot refrigerant is sent to the radiator (this is typically in front of your 'standard' radiator). typically this line is small.

the cool, compressed refrigerant goes to the evaporator in the dash somewhere. usually, there is a holding tank of some sort. this has a valve that slowly expands the compressed refrigerant. this cooled gas flows through the evaporator core. typically this cooled gas is returned via a larger tube to the compressor.

most systems have a low pressure cut off switch. not enough referigerant means not enough pressure. sometimes these switches fail. usually located on the 'holding tank' (i think its a dryer/receiver actually thinking about it).

if the smaller line leading away from the compressor is not warm, then your compressor is not operating. check the relay to the clutch on the compressor. check the clutch. does it engage? (you can typically hear more 'noise' when the clutch engages).

[Jaguar5822]

The small metal tube coming from in front of the radiator is cold, then it goes to the black thing next to the PCM, then the larger tube coming out frmo there is warm, and it warms up the metal tank where the low pressure filling port is on, and the tube coming from that is warm as well. The clutch is engaging.

[Jaguar5822]

No more thoughts? Thanks for the ideas, but I am not sure what the problem could be, considering just taking my car in. What do you guys think would be the cheapest chain place to take it to.
James

[chas]

well that sounds right i suppose. after going through the ducts in the dash the refrig would get warmed up. if its not cold enough and the cluch is engaging then you either have low pressure (apparently not the case), need air purged from the lines, or a weak compressor. (i suppose its possible that the low pressure cutoff not letting the compressor run long enough. if the pcm sees low pressure it will cycle the compressor briefly to see if it can get the pressure up).

[pvtschultz]

Let me see if I can shed some light on the subject or the Brayton refrigeration cycle.

Starting at the compressor, vapor refrigerent is compressed, increasing the temperature and pressure. From there it is sent to the condensor ("radiator" in front of the radiator) where the high pressure gaseous refrigerent is cooled, transforming it to a liquid state. From there is it run through a throtteling valve where the warm high pressure liquid refrigerent in throttled to a cold low pressure liquid/vapor mixture. From there it is routed through the <blockquote>quote:</font><hr> dryer/receiver <hr></blockquote> which is a drier to remove any moisture in the system and into the dash to an evaporator core which essentially boils any liquid refrigerent, removing energy from the air making it much colder. That is the cold air that is routed into your passenger compartment. After boiled, this low pressure kinda cold/warm vapor refrigerent is sent back to the compressor to start the process over again.

The only thing that I am unsure of is the actual placement of the drier, it is either before or after the evaporator core.

So, in laymans terms, the tube running into your condensor (in front of the radiator) should be very hot, it must be much warmer than the ambient air temperature. After the condesor, the temperature should be almost the same as that of the air surrounding everything. The drier should be very cold as well should the return line to the compressor should feel cooler. If the inlet to the condensor is not quite hot, you are either having problems with your compressor, or you don't have enougth refrigerent.

Check the center of the compressor to make sure that is spinning as well as the outside. There is an electric clutch that engages the compressor so the outside always spins, you should here the engine change when the compressor kicks in.

Hope this helps you find the problems.

Please excuse all spelling errors, I am headed for bed. Had an interview with Harley-Davidson today...still pretty stressed out from that.

~Carl