134A freezing up Dryer

[katugly]

I was charging my system after getting it all vacuumed up and the dryer and the lines were getting cold enough that it had a thick layer of frost on it, hard enough that you could not scratch it off without some umph. Today I run it and the system was getting cold but not near like it was yesterday. I still have good readings on the gauges but I guess I’m worried I got the adjusting orifice tube in wrong or something. How do those adjusting tubes work?

 

[Fordum]

When you say dryer, do you mean the one in the high side? If so you have a restriction in it. Its not supposed to get cold.

If you mean the accumulator next to the evaporator, it should not be frosting either.
When those variable orifice tubes first came out, I bought one, but it never worked right. Kept stopping up, or flooding.
Since they are still selling them, I assumed that they had been improved.
But maybe not.

The one I had was "automatic". It self adjusted according to flow, or temp, or something.
It was supposed to give good service at speed and much better than stock at idle.

 

[Blue85]

A little frost is normal, even all the way back to the compressor inlet. However, if it's building up, your low pressure cycling switch is stuck or mis-adjusted. You have a gauge, look at it and you can tell the temperature in the low side. If you're below 32F, then tweak the switch screw a little.

You say it runs different from one day to the next - has the ambient temp changed? Have you changed the fan setting?

If the system is cooling at all, I would be surprised if the tube is blocked or stuck. This is the VOV?

 

[katugly]

I think what may have happened is that The Mixer door was shut on both sides baically not blowing air any where. Thus not warming the evap box enough to keep it from freezing. I opened up the box by hand under the dash the next day and that when it was just condensating but not freezing. I still need to adjust the low pressure switch though becuase its just on all the time. I did get the clevis to fix the door so it opens correctly when you turn on the A/C. I also may have but to much freon in so I will have to take a look at that when I can pull it out of the garage and get a hose on the condenser.

On a related note does any one know if there is a pusher fan out there that I can find in a salvage yard to go on the front of the condenser? I was looking through the yard the other day and there was a late model burb that had one but it was only covering the passenger side of the condenser. Is that how most of the OEM setups are?