How many pounds of freon?

How many pounds of freon should my 2000 4964ex with 72" sleeper take and what temp should I get out of the vents?

 

Depends on how much is in the system now. Get the cans of R134 with a gauge on them and it will tell you when it's full. Should be 40-50 degrees if all is well with the system.

 

I have gotten as low as 30 degrees from a AC system which is really bad. You freeze up then.

We always aimed for 40 degrees below ambient though.

System capacity should be listed somewhere.

If you are having it topped off all the time, have it sucked down and evacuated and vacuum tested for a leak. It should hold a 29" vacuum for over 1/2 hour or more.

If it doesn't, you have a leak that needs to be looked at.

 

Just had it redone at an automotive a/c shop. He said he couldn't put more than close to three pounds in, although another shop quoted me 4 pounds. So for a brand new system, approximately how many pounds. I think he used the wrong dryer because he kept talking about a sight glass, and I've never seen one on a big truck dryer.

 

I have seen them. They aren't common. A replacement might have it on it.

3-4 lbs sounds about right. Like 3.4 to 3.6 is what I remember using the most. I know some systems also had 2.8 lbs in them.

So yeah, they would charge for a full 4 if they used small cans.

Did they charge for oil too?

If you look at the cans, you should notice most are also only 14 oz too.

 

Yep if your running a system with a expansion valve then you most likely have a dryer with a site glass pretty common

 

Yeah they charged 10 for oil and it is an expansion valve sytem. It's blowing 30 below ambient at full blast recirculation. Any ideas?

 

that's not horrible.

Especially if it hasn't been properly evacuated and taken back up.


Was the system just low? or was it recently opened up and serviced?

 

MN new compressor, dryer and some lines and fittings replaced, and the system gone over. It should be doing way better than that.

 

heck yeah it should.


Ask them if they evacuated it and put in a new o-tube. (OK, my memory is OLD on that part. you may not have an o-tube (orifice tube) with an expansion valve.)