auto a/c question

[Car Doc]

Most R134a systems are charged through the high side.

No a/c is charged thru the high side however you can preliminarily fill one using both ports but the high side has to be closed before running the system and finishing charging it!!!

A/C high side pressures are enough to explode a hand held can and at least blow the disc on a bottle and common sense should dictate this knowing the temp/pressure characteristics of gasses.

R-134a having a 32 degree evap @ 26 psi @ 70 degrees ambient for instance.

You need to have the system sucked out and weighed before you would know the state of charge its in and after that the tech will make suggestions but it sounded like it was low and freezing up to me and the fact you were not able to get any in makes me think the charging hose etc was to blame for that in some way?

 

[dstig1]

If it ices up the air will blow warm as the ice insulates the evap so it doesn't transfer heat out of the air very well, but air can still get by. Once it melts, back to normal. It can happen as I described and the system can still be functioning correctly, or there can be a problem that is causing it. The main problem that can cause this is the LP switch not cutting out soon enough.

If the low-side pressure in the system drops too low, the temp of the evap drops too low (below 32F) and ice starts to form on it. The LP switch is there to switch the clutch off before the pressure gets that low to prevent icing. That is what cycles the compressor clutch in normal use - especially in cooler weather. It also prevents the system from operating if there is a leak/low freon charge causing the system pressure to be too low to prevent compressor damage from running "dry".

If it continues to work fine, I would say it was just icing due to the conditions she was running it at and the temp/humidity. Don't run Max AC/Recirc with low fan settings, and that would solve that issue. Otherwise I need more info to go further on finding the cause.

 

[YesDeere]

You can charge on the high side (liquid) A fast way to do it. Just make sure the bottle is upside down and weigh it. Then give it at least twenty minutes to equalize. I never do this on 134a but you can. Just be careful.

Honda had some problems a few years back with their compressors. I've replaced a few. And when a small dealer has them in stock you know it's an epidemic.

Oh. Forgot to say. Most liquid charges are done with blends so they go in equal amounts. Because different gasses "boil" off at different rates or temps when "gassing"

 

[deerefan]

If it ices up the air will blow warm as the ice insulates the evap so it doesn't transfer heat out of the air very well, but air can still get by. Once it melts, back to normal. It can happen as I described and the system can still be functioning correctly, or there can be a problem that is causing it. The main problem that can cause this is the LP switch not cutting out soon enough.

If the low-side pressure in the system drops too low, the temp of the evap drops too low (below 32F) and ice starts to form on it. The LP switch is there to switch the clutch off before the pressure gets that low to prevent icing. That is what cycles the compressor clutch in normal use - especially in cooler weather. It also prevents the system from operating if there is a leak/low freon charge causing the system pressure to be too low to prevent compressor damage from running "dry".

If it continues to work fine, I would say it was just icing due to the conditions she was running it at and the temp/humidity. Don't run Max AC/Recirc with low fan settings, and that would solve that issue. Otherwise I need more info to go further on finding the cause.

Ok I see. Thanks for educating me. I will let her know about the fan speed and post back to any new findings.

 

[Car Doc]

Not one car manufacturer in the world uses a blend and it matters not anyway how they go in the system long as its done right. :laughing:

Anyone who believes some of this mis-info on this thread is in deeper than they want to be so better let the pros take care of it and forget about dispensing this garbage or listening to it. :thumbsup:

 

[YesDeere]

Car doc. Was just trying to clear up the high low side charge and talking about freon in general. The ports for 134a are different for a reason. So mistakes aren't made with different gasses. Never said any car had a blend. Do you feel better about yourself now??;-)

 

[Car Doc]

Car doc. Was just trying to clear up the high low side charge and talking about freon in general. The ports for 134a are different for a reason. So mistakes aren't made with different gasses. Never said any car had a blend. Do you feel better about yourself now??;-)

You said it not me dear so just how stupid do you think we all are?

This is you.........

"You can charge on the high side (liquid) A fast way to do it."

"Oh. Forgot to say. Most liquid charges are done with blends"

Here is me.....

"No a/c is charged thru the high side however you can preliminarily fill one using both ports but the high side has to be closed before running the system and finishing charging it!!!"

"You need to have the system sucked out and weighed before you would know the state of charge its in and after that the tech will make suggestions but it sounded like it was low and freezing up to me and the fact you were not able to get any in makes me think the charging hose etc was to blame for that in some way?"

Looks like this is more about how you feel than me I care less how you use freon in general your success at it will reflect your knowledge of the task at hand dont quit your day job.

cheers

 

[YesDeere]

Stick to cars please. Car cobbler

 

[deerefan]

Stick to cars please. Car cobbler

Guys, I appreciate all efforts to help. I would like to keep this thread above the belt and open as the problem is not yet solved. Please be respectful. If you need to bicker, do it thru private messages. Now, the car is on its way here and the a/c is still working. I will put my gauges on it, get a reading, and report back. I think the low pressure switch, from what I have read here, sounds like the culprit.

 

[YesDeere]

My apologies deerefan. Hope you get it fixed. But freon is a touchy subject.