R134a Red or Blue Orifice Tube - Ford Bronco Forum
LinkBack Thread Tools Display Modes
post #1 of 8 (permalink) Old 09-01-2007, 07:44 PM Thread Starter
Registered User
Join Date: Sep 2006
Posts: 50
iTrader: (0)
R134a Red or Blue Orifice Tube

I did a quick conversion on my AC system last year. Just grabbed a conversion kit from Autozone and put it in. I did not change the receiver dryer, orifice tube or draw a vacuum on the system. It worked OK, but the charge leaked out by this year. At the begining of the summer I refilled but it has leaked down and I had to top it off already. We've got another month or so of 100 plus, so I'm going to go ahead and do it right.

The compressor was changed over a few years back (6-7) and is rated for
R12 or 134A. I picked up a cheap venturi vacuum pump ($9) and gauge set ($39) from Harbor Freight. I know they are not the best, but will work for me. I am going to do it right and put in a new Receiver Dryer, change the O-Rings and Orifice Tube. My question is this (and yes I searched) which color of Orifice Tube do I use? Red, Blue, or the cheap variable one from Checker? I know a smaller size is recomended for a conversion. For GM conversions they recomend using a Ford blue Orifice Tube, but the red is slightly smaller. Right now I plan on using the red. Does anyone have any experience, or does it matter? My Bronc is an '89 with a 302.

Thanks in advance!
Redmonaz is offline  
Sponsored Links
post #2 of 8 (permalink) Old 09-01-2007, 09:11 PM
Registered User
tonythetiger57's Avatar
Join Date: Dec 2005
Location: St.Louis MO
Posts: 156
Bronco Info: 1984 Ford Bronco XLT 408 W
iTrader: (0)
Mine in my 84 is blue...

1984 FSB XLT, 408 Stroker ,8 inch lift, SAS, powdercoated frame, ram air hood, c6 tranny, shiftkit w/deep pan, 4:11 gears, detroit locker in rear. New pics in about a year when its all together.
tonythetiger57 is offline  
post #3 of 8 (permalink) Old 09-01-2007, 09:27 PM
F*ck 'em all
92builtbronco's Avatar
Join Date: Sep 2006
Location: San Antonio, Tx
Posts: 2,422
Bronco Info: 1992 Bronco XLT 351, E40D, York OBA, 3G Alt, 3" body lift, 4" susp lift, 4:56s, 36"x15.5 Dick Cepeks
iTrader: (0)
I just rebuilt my a/c system last week. Iirc, according to the Ford parts catalog 90-96 are red. That being said, I pulled what was left of a blue one out of mine and replaced it with a red one. It works great now.

It had been converted to 134 by the PO.
92builtbronco is offline  
post #4 of 8 (permalink) Old 09-01-2007, 10:09 PM
Satyr of the Midwest
SigEpBlue's Avatar
Join Date: Nov 2005
Location: Ida & Grand Rapids, Michigan, a.k.a The Unemployment Capital of America
Posts: 17,752
Bronco Info: 1993 EB, 5.8L, BIO0 MAF, GT40Ps, Mustang cam, GT40 Intake, Custom Headers, Moates QuarterHorse
iTrader: (2)
Go red. Blue is too large and will perform badly, i.e. not cool down the evaporator. R134a needs a larger pressure differential, and using a smaller orifice tube is how you do it. Don't bother with the variable orifice; it's overpriced and just another thing to fail, IMHO.

Wheelin' across Michigan from Ida to Grand Rapids, baby!
Nemo nisi per amicitiam cognoscitur -- No one learns except by friendship.
Originally Posted by Adlai Stevenson
Isn't it conceivable to you that an intelligent person could harbor two opposing ideas in his mind?
SigEpBlue is offline  
post #5 of 8 (permalink) Old 09-04-2007, 10:28 PM
Registered User
Join Date: Jul 2007
Location: Forsyth, Ga
Posts: 6
Bronco Info: 1989 bronco eddie bauer edition 4x4,
iTrader: (0)
i have an 89/302 also and just swapped my AC about 2 months ago; the book called for the blue oriface. Just make sure you vac it down good and be sure you dont charge it on an extremely hot day or it will not fully charge. you may get a vapor lock in the system also. as i said though make sure you vac it down good. if you use the venturi vac let it vac for about an hour to remove all of the oil and moisture.
scott2007 is offline  
post #6 of 8 (permalink) Old 09-20-2007, 03:34 PM Thread Starter
Registered User
Join Date: Sep 2006
Posts: 50
iTrader: (0)
I wanted to add an update so if anyone finds this with a search they will know the final outcome.

I finaly got the system properly swaped to 134 and it works great. You can't have it blow directly on you, after a couple of minutes its too cold!

I used the red orifice tube. From my research the red or blue would have done the job, but the red is what was used in newer trucks designed for the 134A. I had to buy a large kit of O-Rings ($20) to make sure I had all the ones I needed (it costs $7 in gas to run back to the parts store). It turned out I needed 2 large ones for the compressor that were not in the kit, another $2. I put in four 12 oz cans of R134A (2.50 ea. On sale + rebate) and 1 can of oil ($10). A new receiver dryer ($40) and a red orifice tube

I also bought a set of gauges ($40) a venturi vacuum pump ($10) and the tool for the orifice spring clamp ($5) from Harbor Freight.

I opened all of the connections, removed the orifice tube, and blew out all the lines with a compressor. Then I changed out the receiver dryer, orifice tube, and replaced all the O-Rings. Using the new gauges and vacuum pump I drew a vacuum on the system for about 10 minutes and closed the gauges and went in to dinner. 30 min late it was still holding a vacuum so I hooked up the vacuum pump and drew another 20 min of vacuum. It sucked in almost one can of R134A on its own. I then cranked it over and added one more can of R134 then the can of oil and then the remaining 2 cans of R134.

Total cost $85 in parts and $55 in tools. That includes enough O-rings for 10 cars! Would I do it again? YES! It was very straight forward and simple! What I wish I would have known before: 1) The harbor freight scissor type tool for the spring clamp is a piece of junk and does not work. I had to grind the edge so it would get under the spring. Pay the money to get a good one, even if it is only one size. 2) You can get the orifice tube out by blowing air into the condensor opening, but put a towel over the opening so you don't launch it into your neighbors house!

The system is not showing any signs of leaks and I'm sure it will work great next year. I may not own it to make sure though. I'm picking up another proect car and we don't need 5 cars for 2 drivers.
Redmonaz is offline  
post #7 of 8 (permalink) Old 09-20-2007, 03:47 PM
crank trigger
Join Date: Jul 2005
Location: Colorado
Posts: 8,160
Bronco Info: 94 XL M5OD, 5.0, Ghetto K&N, 130A G3
iTrader: (0)
i thought you were supposed to add oil to the different parts then pull the vacuum.
ScorpionBoy is offline  
post #8 of 8 (permalink) Old 09-20-2007, 04:16 PM Thread Starter
Registered User
Join Date: Sep 2006
Posts: 50
iTrader: (0)
I think the Ford compressors take the oil directly. My compressor was replaced a few years back and looks different than what I've seen pictured on here. I assumed it was a standard after market compressor. I could not see where to add the oil directly and I thought if I put it in the hose openings I would vacuum it out. I could be wrong, but it seems to run smoothly.
Redmonaz is offline  

  Ford Bronco Forum > Bronco Discussions > 1980-'96 Bronco Tech

Quick Reply

Register Now

In order to be able to post messages on the Ford Bronco Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Please enter a password for your user account. Note that passwords are case-sensitive.


Confirm Password:
Email Address
Please enter a valid email address for yourself. DO NOT USE Gmail.com accounts. If you only have a Gmail.com email please contact the administrator here

Email Address:


Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.

Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode

Posting Rules  
You may not post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

For the best viewing experience please update your browser to Google Chrome