Recharging refridgerant?

[spta97]

My buddy with an older Mercedes had his refridgerant recharged this weekend for about $80 and he said it made all the difference in the world likining it to a meat locker.

He described similar performance to mine - works fine at night, but not freezing while the sun is out. From a 2000 V8 what kind of cooling can I expect in the cabin? Is there an easy way I can tell if it's low? I would like to be blasted to the north pole if possible

 

[BradE.]

You need a set of manifold gauges to measure the low pressure side of the AC system to test if it's low.

 

[spta97]

You need a set of manifold gauges to measure the low pressure side of the AC system to test if it's low.

Sounds like it might be worth having it checked out professionally?

 

[Hokie-Dave]

You can also get a $20 kit at your local autoparts store that comes with a can of refrigerant and a gauge on it. Hook it up and see if it is low, if it is then squeeze the trigger and fill it up to the "normal" range on the gauge.

 

[spta97]

You can also get a $20 kit at your local autoparts store that comes with a can of refrigerant and a gauge on it. Hook it up and see if it is low, if it is then squeeze the trigger and fill it up to the "normal" range on the gauge.

Do they still sell those? I remember with R12 they stopped after it was banned.

 

[james t]

Yes, they sell them for 134. I just topped mine off a few days ago and dam its nice having cold air again.

 

[spta97]

Do you know where on a 5.0 V8 I would connect it to?

 

[james t]

Passenger side, black cap.

 

[spta97]

Excellent - thanks.

Was your cooling like mine? (good at night, not so good in day)

 

[Hokie-Dave]

It was cooling marginally. I really can't recall whether it was good at night and not during the day though, I just recall that it wasn't blowing as cold as I would have liked it too.

 

[spta97]

Thanks for the replies. I'll see if Autozone has the charger kit.

 

[spta97]

Ok, so I picked up the kit at AutoZone and took a reading. The pressure was reading around 30 lbs and according to the chart it should have been between 40 - 50. As I was adding refridgerant the gauge would jump up into the red so I would back it off. After a few times of this I was only able to get it up to 35 lbs. Figuring the can was empty I took off the valve and was surprised by a long woosh as the R134a rushed out.

I went back and put on a 2nd can and it would go up to 40 as I was filling but as soon as I backed off it would go back to 35 - the can still having refridgerant in it. So here are my questions:

1) How long does it take for the can to empty?
2) Can I expect the a/c to get any colder than 47 degrees farenhight at the vent?
3) Is it bad to allow the pressure to climb into the danger zone while filling?

Please help me

 

[Bruce Rock]

1) How long does it take for the can to empty?

That depends on the temperature. I added some to the sable a couple of days ago. I'd say it took at least 15 minutes.

Remember, in the can the R134a is a liquid. It has to change to a gas to get out. That takes energy. It get the energy by lowering the temperature of the can. When the can no longer feels cold, the can is empty.

2) Can I expect the a/c to get any colder than 47 degrees farenhight at the vent?

Not really

 

[spta97]

Thanks for the reply - I thought it would be like 1 minute! I did some research online last night and there were ideas to put the can in warm water to help it despense better. Since it is low I'll try to be more patient and give it another shot but I won't expect too much more cooling from the vents.

 

[Bruce Rock]

2) Can I expect the a/c to get any colder than 47 degrees farenhight at the vent?

Let me explain. The closer the temperature gets to 32 degrees the more risk you will have that the condensate from the evaporator, instead of running onto the ground, will freeze blocking the air flow thru the evaporator.