[turkxmax]

Hey guys,

I decided to fix my A/C after a year so. I read up almost every AC issue related threads so as a result:

I recharged it. It did not work, but it kept turning on and off. I did not want to bother with checking the compressor clutch so I bought a new compressor for cheap. Recharged it again.

It still does the same thing. Here is the video:
As you can see, the pressure is good, it goes down when the compressor spins. No cold air still.
There are no visible leaks

Any thoughts? I'm about to order a service manual for wiring diagrams.
I am tempted to take it to AAMCO but I wanted to get some inputs from your guys first.

Thanks in advance

 

[RT]

Take the wire off of the low pressure switch - on the drier. Temporarily short it with a paper clip. If that keeps it running, the low pressure switch is causing the cycling. If that's not it, it has to be the high pressure switch.

When you changed the compressor, did you vacuum the system down? Did you change the orifice tube? The drier? It really takes a gauge set monitoring both high side and suction side pressures to accurately diagnose this. You could very well have an internal obstruction.

 

[turkxmax]

The compressor works constantly when i jump the switch! (Do you know what needs to be changed? )

But there's still no cold air...the pressure is low and I cant fill it up with freon for some reason.
I guess I need a full flush?

 

[RT]

That test indicates either the switch is bad or that the pressure is dropping below about 25 PSI the second the compressor kicks in. So, ask why would it be doing that. The most common cause is being low on freon. You want a steady 32-34 psi on the low side. Again - did you completely vacuum your system after the compressor was re-installed? That is absolutely critical. Air is essentially a non-compressible gas in relationship to freon. Plus, vacuuming to as close to an absolute vacuum you can get removes moisture from your system - not doing that is a death sentence for your new compressor

That said, if you did vacuum it properly, and did put on a new drier, then you should be able to add freon. Flushing isn't the answer. The pressure from the can should be enough to keep the low pressure switch from cycling. Just out of curiosity, what's your location? There might be someone close with gauges and a vacuum pump.

 

[turkxmax]

I got a vacuum but don't have the right connectors.
I think I will go to PepBoys so they can vacuum it and fill it in for me tomorrow.

Rockauto has the Accumulator/Drier for $23+shipping
Napa has the A/C Low Pressure Cut-Out Switch (Part #: ECH RPS619) for $20.

So should I vacuum the system before or after I change the Accumulator/Drier and the Orifice tube?


I am in Central Jersey near Rutgers University.

 

[RT]

You would have to evacuate the system - then change out the parts - then pull a full vacuum - the longer the better. I frequently leave it on for a few hours, but anything is better than nothing. Then you would charge it.

If you've never changed an orifice tube before - you might want to have an experienced friend give you a hand. They sometimes are hard to pull. The reason to change it is there is a screen on the tube that becomes plugged over time. Its just a good thing to do while you've got it open.

 

[turkxmax]

OK. I ordered everything and will be keeping the thread updated.

Thanks sir!

 

[lance1955]

Rt is correct. I will add though you need to look at the fan shroud. It will tell you in LBS and Ounces how much R-134A the system holds. When you go to recharge the system next time after the vacuum is pulled. Have a helper in the truck and hold the Idle at 1500 RPM while charging.

 

[turkxmax]

I found a leak where the hoses attach on the Accumulator/Drier.

I believe its the O-ring. I'm gonna try to do the vacuum myself but I dont know how to do it. So I'm going to try to follow this guy.

I bought one of those things with the 3 hoses

 

[RT]

Did you change out the orifice tube yet? To vacuum it, attach the blue hose to the low pressure side. You don't have to attach the red tube to the high side, but you can if you want. Attach the yellow tube to your vacuum pump. Turn the vacuum pump on and then open the valve on the blue side of your gauges. You want to get as close to -30 psi (absolute vacuum) as you can for as long as you can - a couple of hours is good. You can then close off the blue side valve and then turn your vacuum pump off. Some people will then watch the vacuum for a few hours to make sure there aren't any other leaks present. Then you charge your system. When you put your can of freon on and puncture the top with the tap, you should crack the yellow hose where it mates with the gauges for a second to expel the air that was in the hose. Then charge it. Like Lance said, the total charge weight will be posted on a sticker under the hood. Ultimately, you want a low side pressure of about 32-34 psi.

Personally - I wouldn't do any of this if you still have your old orifice tube and drier - better to do it right once than to have to spend $$$ for multiple charges.

When you installed the compressor and changed the o-rings on the drier - did you wet them down with refrigerant oil first?

 

[turkxmax]

I'm waiting for the orifice tube and drier to come, once they're here I'll do this procedure.

 

[turkxmax]

Need some more help please.

It sounds like the leak is coming from the area with BIG RED dot.
What is under than plastic cover...It is well hidden and covered so need to take a lot of bolts to get to it.


The SMALL RED dot goes to whatever is under there.

Anything on that "thing" that would cause the leak?

Thanks

EDIT:

So I found out that its the evaporator core and I'm going to replace it because it's leaking from one of the lines on it

 

[RT]

That's the evaporator core. Its a smaller radiator like device that does the heat transfer on the "cold" side of the a/c. Basically, the freon is sprayed out past the orifice tube into the evaporator which is what your blower moter blows through to get cold air into the cabin.

View attachment evapcore.pdf

Are you sure its a leak? There is a sound produced as freon flows through the orifice tube. Sometimes for a little while after the motor is turned off as pressure equalizes. I would see if your pressures decrease after a day or two before I pulled it apart.

 

[turkxmax]

I could feel freon shooting out from the evaporator so I decided to take it out. And since it was never taken our before, it would be a good maintenance.

Here's what I found:

So next step is to put the new evaporator in, vacuum again, then recharge.

Am I also supposed put any refrigerant oil after vacuum?

 

[RT]

You can put in 1-2 ounces of PAG - put it in before you vacuum - pour it directly into the drier. That picture is EXACTLY why I suggest changing the orifice tube any time you've got your system open. That screen is the only "filter" in the whole system. Good work. I predict you'll be freezing your butt off shortly.

 

[RT]

OK - time for an update? I guess you've been too busy driving around your ice cold PSD to get back on..

 

[turkxmax]

Not yet,

Rockauto takes 2-3 days to ship.
I should be ready by Thursday.

Happy Independence Day to you in advance sir.

 

[RT]

And to you as well - although we celebrate independence day on March 2nd in the Republic of Texas...