Correct AC orifice Tubes

I have two trucks that are AC / 1990 that have been retrofitted to r134a, they both work OK but I never changed the orifice tubes when I revived them. I remember reading about some people switching to a different color tube, and I wanted to try that (or just replace one) on one of my trucks and see if that does anything to my cooling performance but I can't find a thread that specifies which color it was.

Recommendations? And I read online you need a puller to get the orifice tube itself out of the line going to the evaporator but I never see the tool. The ac in these isn't bad, I'd say it's 8/10 honestly it freezes you to death unless it's above 90 out and then it's just good enough to keep you cool but I'm wondering if a partially blocked orifice tube could be my missing link to slightly better performance when its above 90 as both trucks have new evaporators / condensers as well as O rings when I revived them.

I used a red one in my Crew cab. Seems fine but someone mentioned I should have used an orange one...

From what I've read I'd put a red one in if you change it. I didn't use a puller because I had a brand new evaporator core. If you decide to go with a blue one instead I think I have a new one that came with the evap core but I didn't use it.

On removing the orifice tube: When I tried to remove mine, with small needle nose pliers, the plastic "tab" on top broke. I tapped (knocked) a sharp probe into the interior of the tube and used the "flush tank", from O'Reilly's, to push air through the evaporator wile I worked the orifice tube out with the probe. This method has worked for me twice.

Autozone rents the orifice tube tool. I've never had issues breaking one off using the correct tool. Have had to fix plenty by people not using the tool.

It's been several years since I've converted a system, but I usually reinstalled the stock valve for r12. I've heard you could go one size smaller for better cooling at idle, but have never done it. The stock size always seemed to cool fine.

If you're looking to change/upgrade. Get a variable orifice tube and use that. Everybody I've talked to that has done the switch speaks highly of it, especially in high ambient temps or high humidity. I haven't done one though so I can't comment from personal experience.

Booyah45828 said:

Have had to fix plenty by people not using the tool.

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How'd you fix them?

Remove it, put a new one in the correct way.....


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79jasper said:

Remove it, put a new one in the correct way.....

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My question was regarding the "fix" after the wrong tool has been used for the attempted removal.
As far as I know, the only tool required for install is a finger.

A little tool that looks similar to an easy out. It's really long and slender tool steel shaft with threads on it and you essentially screw this in until the tube rotates and then, using a lever action, you pull the tube out.

It threads into the actual tube, after the plastic housing is out of the way. Works pretty well. Sorry I don't have a brand or part number for you, there is nothing on the tool itself.

The challenge (at least for me) was separating the flexible line from the rigid line to gain access to the orifice tube. This requires a special, inexpensive tool (see pic). Removing the orifice tube itself, I just used a pair of needle nose. Also, I used a "blue" replacement orifice.

Kizer said:

My question was regarding the "fix" after the wrong tool has been used for the attempted removal.
As far as I know, the only tool required for install is a finger.

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I've seen some use a screw to grab it, then just pull it out.

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I used the orange orifice tube on my '88 van.



As for the tool, I just bought the thinnest harbor freight needle nose pliers, and used my bench grinder to make a groove on each side so that the tip had a tooth to catch the tube with.

That's the tool HFT I use, always pour a little refigerant oil in there to help loose it up. The o rings will be dry and they will stick, take the needle nose pliers and trun it left and right and it should pull out. Good luck.

Read somewhere that the 94+ factory R134 systemd usually used the red tube. That's what I installed in mine when i rebuilt the entire system and it is colder now than with the old system 'converted' to R134 (had the blue tube). However it's not quite an apples to apples comparison either as I also installed a new evaporator and condenser from a factory be 1994 R134 system while I was at it.

I also tried a variable orfice tube, a supposed high quality expensive one, failed within a few minutes blocking the flow of refrigerant.

1993 F350 Crew Cab Dually
XLT
7.3 Factory IDIT w/Banks Sidewinder
5spd Manual

I don't remember the color, but I used a variable orifice tube. Vent temps of 35*F on a 95* East Texas summer day.

When retrofitting to r134a you use 15% less refrigerant. You should also use an orifice that's 15% smaller. The orange tube is very close to this if you removed a blue tube.

You my also need to adjust your cycling switch to go off @ 20, on @40.