Blue Orifice Tube or White? Which is best? R134A

[Sal 87WE2]

I am in the process of converting my system over to R134A and i have searched extensively on this topic. Which is the best orifice tube to use? I do not have a front mount right now but *may* consider one in the future. From the search i have gathered a couple say use the blue and others say the white is fine. Some say the blue does not work well with a front mount.

 

[charlief1]

Do yourself a favor and get one for a 95 Ford (yes I did say Ford) PU. Make sure it's the red one. It's almost identical but it has 2 holes in it so it will drop the temps between 5 and 10 degrees. I do this all the time when converting AC systems.

 

[Sal 87WE2]

Do yourself a favor and get one for a 95 Ford (yes I did say Ford) PU. Make sure it's the red one. It's almost identical but it has 2 holes in it so it will drop the temps between 5 and 10 degrees. I do this all the time when converting AC systems.

Ok, will do.

Have you heard anyone complain about the red one when they have a front mount installed?

 

[charlief1]

Never had any complaints yet but there's always a first.

 

["Turbo-T"]

Do yourself a favor and get one for a 95 Ford (yes I did say Ford) PU. Make sure it's the red one. It's almost identical but it has 2 holes in it so it will drop the temps between 5 and 10 degrees. I do this all the time when converting AC systems.

I'm in the same dillema...I'll presume that's an F series truck you're speaking of ...do they all use the same one?

Also someone once told me the one off of a 91-94 Lumina is good to use....???

 

[t-topflyer]

Anyone have a part number for the orifice tube? If I go in to autozone and ask for a red orifice tube for a 95 Ford PU there going to ask me 2 or 4x4, F1, 2, or 350, 4.9, 5.0 or 5.8L......you get the picture............

 

[Sal 87WE2]

Anyone have a part number for the orifice tube? If I go in to autozone and ask for a red orifice tube for a 95 Ford PU there going to ask me 2 or 4x4, F1, 2, or 350, 4.9, 5.0 or 5.8L......you get the picture............

Haha, yes they will! I told them 95 F150 5.0

Here is the p/n: Factory Air - 38635

see pics:

 

[t-topflyer]

awesome thanks!

where is the orifice tube located on the GN?

 

[Roger]

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To get optimum results, you'll also have to update the condenser & evaporator. 134 is not as efficient as R12 & runs at higher pressures.

Replace the rubber hoses in the lines which run to the compressor (I have seen them leak - not good when your working under the hood) & they are at least 23 years old.

 

[charlief1]

If you get an idiot parts guy then just make it up as you go. Any 95 Ford PU and any options you want. 1/2 to 1 ton will work.

 

[Sal 87WE2]

Another question: How the heck do you spin the compresser while its off the car to move the oil around?

 

[charlief1]

Inside the center of the hub is a bolt head. Use a rachet and slowly turn it.

 

[TURBOTWIN2]

Charlie sounds like he knows his stuff.
How much R134A freon do you like to use? 80% of the R12 amount? Which I'm thinking is 3 1/4 lbs. off the top of my head.
I'll be doing this retrofit soon.

 

[charlief1]

The best way is to use a remote temp system to check temps on the inlet and outlet of both the condensor and evaporator. Kinda pricey for me right now. If you acheive a low side pressure of 45 PSI you should be fine. the high side won't matter that much since it's R-134 but it should be lower than 250. If it's higher than that you have a condensor that's not working right or a cooling fan that's not working.

 

[norbs]

You will choke off your a/c at higher speeds the smaller the orifice tube resulting in less cooling at highway speeds, however the smaller tube will help idle. What the diameter of the red tube? I had a little bit better results with a variable tube.

 

["Turbo-T"]

You will choke off your a/c at higher speeds the smaller the orifice tube resulting in less cooling at highway speeds, however the smaller tube will help idle. What the diameter of the red tube? I had a little bit better results with a variable tube.

Same thing I'd like to know, and how well the 95 Ford orfice tube works at both low and high speeds.

 

[49-blues]

Sal- how did you do with that leak? Did you change the oil out to Ester? Charlie-did you go to school for Ac or back yard mechanic, at 45 psi the refrigerant temp is already at 50*-I set mine up at 30 psi where refigerant temp is about 35*.

 

[87GN_70GS]

The stock GM orifice tube will cool better at low engine speeds. Do a search on the ac kits forum.

The ford orifice will do better at highway speeds, but that is not where extra cooling is needed.

 

[charlief1]

Same thing I'd like to know, and how well the 95 Ford orfice tube works at both low and high speeds.

The big difference is in the pressure differentiation. The higher the pressure drop the more it will cool. At low speeds the pressure doesn't have that big a difference but at high speeds the change of state and the pressures are much further apart.

Sal- how did you do with that leak? Did you change the oil out to Ester? Charlie-did you go to school for Ac or back yard mechanic, at 45 psi the refrigerant temp is already at 50*-I set mine up at 30 psi where refigerant temp is about 35*.

I'm a degreed ASE Master Tech blues. I spent 2 years in school to earn my Associates with a 3.42 GPA, Texas VICA runner up in competition, and have been working on cars since I was 18. So does that help?:biggrin:

 

[Sal 87WE2]

Sal- how did you do with that leak? Did you change the oil out to Ester?

No, since my system was completely empty AND everything is/was brand new i went wth PAG. Originally i had ester but that was with the original Evap core....

The stock GM orifice tube will cool better at low engine speeds. Do a search on the ac kits forum.

The ford orifice will do better at highway speeds, but that is not where extra cooling is needed.

I that it was the other way around