AC folks - a question

[White Horseradish]

The Minnesota heat finally got to me and I decided to fix the AC in the truck before I fell asleep in traffic and ran off the road. To that end I took off the drier and the twin hose that bolts to the compressor, I have new replacements for those. For the rest I got one of those big "AC flush" cans. The flush backflowed a bit  and was kinda hard to push through with compressed air. I thought for a few minutes and realized I forgot all about the orifice tube. With that in mind I undid the lower fitting of the condenser and found nothing. No orifice tube. The condenser I can get air through, but is seems to be the source of the resistance to the flush.

So, is it possible I have a Chevy that does not use an orifice tube? Or is this an artifact of the previous owner?

Also, is the condenser supposed to be fairly hard to blow through? Or should I be looking into a new one?

[Jim147]

Condenser could be full of oil. Do you have any nitrogen or CO2 you could try to blow it out with?

It could have a TXV instead of an orifice tube. What make, model and year do you have?

I would have skipped the flush unless you had a compressor burn out.

jim

[White Horseradish]

It's a 93 Chevy pickup. I went with the flush because it's an R12 setup. I don't have any nitrogen, just an air compressor.

[Jim147]

That is an orifice tube system. I haven't looked at a chevy in a while. It should be in the small line between the condenser and evaporator. It might also be in a fitting in that line between the two coils.

Blowing a system out with air isn't really recommended. Adds a lot of moisture to the system. If you do, you might want to put it back together, pull a vacuum and then add some POE oil and then pull another vacuum before charging.

jim

[White Horseradish]

Bottom fitting of evaporator is the only place straight enough to house it.

I know about the moisture, but I did plan on vacuuming it for a while.

[Parker Dean]

I can't remember specifically what the underhood area of a 83 Chevy truck looks like. I mean, I have a general mental picture but specifically how the refrigerant lines are connected I no longer remember, Anyway it's a CCOT system for certain and the orifice is either in the inlet of the evaporator or in a metal section of the high pressure liquid line, identified by crimped areas in the metal. I do recall these were the trucks that used steel nuts to connect aluminum components with predictable, and expensive, results

[White Horseradish]

I had one bad nut - connecting soft brass fitting of the condenser to aluminum  tube. I managed to get it apart without major losses by cutting the nut since i am replacing that hose anyway on account of it being old rubber.

[never_retreat]

You could set up one of these.

[280plus]

Hey!! I installed that!! The customer's name really was "Bubba" too!  

PS, sorry, don't know nuthin' bout no car A/C

[White Horseradish]

Mystery solved. Bubba wuz here.

The orifice tube was where it was supposed to be, but the tail on it was broken. Surgical clamps FTW!. Perhaps someone tried to get it out and failed.

I think I got about all of the flush out of the condenser and just about all of it from evaporator. I an going to start hooking it back together and out the vacuum to it for a couple of hours.

[280plus]

put a little refrigerant vapor in there to like 20 psi, let it out, evacuate to 28", repeat this process three times. THEN let it sit as long as possible on the pump. 24 hours is best. using air is a scary option especially when it's humid out. Good luck!

[White Horseradish]

I think I should have waited to start putting things back together until you wished me luck. The damn accumulator can does not fit. Size and shape are right, the threading is different. Grrrr...