Hyundai Forums banner
1 - 5 of 5 Posts

·
Registered
Joined
·
43 Posts
Discussion Starter · #1 · (Edited)
I had high pr. a/c leaking hose fixed for leak. I believe this hose goes into compressor. I refilled refrigerant at low port and now car is having intermetint hissing sound when we turn a/c on....... Still a/c is not cooling car as it should

Can you help me trouble shoot hissing sound or what to do to fix a/c..

On the other note :-.

1) When A/c is off... at low port ..refrigerant quantity is reading little higher than green-zone...

However
2) When A/c is on...with low temp/full blower setting...then refrigerant quantity is reading low after refrigerant bottle refill.... I don't see leak around anywhere...Any idea what to do to trouble shoot ?
 

·
Registered
Joined
·
163 Posts
It sounds like you really need to get someone who knows about AC to work on it or with you.

You can't just refill the AC after opening the system. You need to pull a full vacuum on it for at least 30 minutes to boil all the moisture out. Without doing that, it's not going to work well, or long.

The pressure while the system is off is next to meaningless. That said, it should be higher than is sounds like it is. You can't tell very much just looking at the low side pressure. You need to look at both the low and high sides at the same time and compare that to a chart that take in the ambient temperature. Also the procedures to get correct readings vary from car to car. Almost always they want all the windows open, blower on high, and temperature on minimum. Some also want the engine at a specific higher than idle speed.

The correct way to charge an empty system is to weight in the correct amount of refrigerant. Also, you probably should have added a little of the correct compressor oil, as some (but not much) was probably lost when the system was vented.

If your car has a thermal expansion valve (it probably does, I don't know for sure with Hyundai), then the hissing sound is the expansion valve being unable to fully compensate for a low refrigerant level.
 

·
Registered
Joined
·
43 Posts
Discussion Starter · #4 ·
agree. it could have moisture trapped inside... I think pr. read around 10 just before I refill with a/c on...So it was not absolute zero... i see UV die can help me indicate leak or as you said holding full vacuum for 30min will be another way to see system can hold and indicate it has no leak...

I don't have vacuum pump to get moisture out, i was wondering if system will get rid of moisture itself as refrigerant level is or was not absolute zero.... Other way will be buy UV-die refrigerant bottle and try to check leak... & yes, refill kit indicated it did had compressor oil in...

Seems like i will need to shed $ to repair shop.
 

·
Registered
Joined
·
163 Posts
Nope, not remotely. The only way is with a good vacuum pump (not the kind that work from an air compressor). Zero is not close to vacuum. Also, you really should replace the dryer material anytime the system is opened. Even a fresh new dryer is not enough to remove all the moisture if you don't pull a full vacuum.
 
1 - 5 of 5 Posts
Top