variable orifice tube ?

Well, I'm finally getting around to fixing and converting from r12 my AC, it died a couple years ago. Now with the truck running great with new IP, brakes, tires, smf and clutch, making long hauls this summer is pretty uncomfortable.
I've purchased : compressor
receiver dryer
o rings
Estor oil
r134
flush
blue orifice tube (variable)
orange orifice tube ( I guess fixed)

The rest is original, including condenser (old style). One question I have: is a variable blue orifice tube as good , worse, or better than an orange one?
Any of you experts I would appreciate your opinion, and especially chris142 I know you really are the
pro with this.
Also how many ounces of oil, and how many ounces of R134? I understand it should be 15% less R134
than R12, but I'm not sure what was original. 1993 factory installed AC. Did I read here 8 ounces of oil?
Thanks for your time.

All I have is a manual for 1984. Back then, the trucks held 56oz r12, plus 4 oz, minus 0 oz. I can't seem to find the oil charge except I found the compressor holds 10 ounces.

Napa lists two different variable orifice tubes, one for 95-105* ambient and one for >105* ambient, one looks red and the other looks black. See them Here. Make sure you get in the duct work and clean the evaporator as well, they are mostly gunked up after this many years. In our '91 I used the newer larger condenser, variable orifice tube, new evaporator and dryer and I consistently had vent temps in the low to mid 30s running down the road with the high humidity heat here in Houston. In stop and go it would rise to the low to mid 40's.

I thought retrofits needed PAG oil.

For '96-'97 F-series they took 38oz of R134.

This post has some of the volumes you need in the documents posted there.
https://www.oilburners.net/posts/1058665/

Also consider installing a heater core isolation valve as described in a later post.
https://www.oilburners.net/posts/1058849/

Don't forget to adjust your low pressure switch as described in those docs as well.

The Service manual doesn't describe a total volume for oil in the system but describes how much to place in each component as they are replaced.

Section 12-00: Climate Control System, Service
1996 F-150, F-250, F-350, F-Super Duty and Bronco, F-Super Duty Motorhome Chassis Workshop Manual
SERVICE PROCEDURES
Refrigerant Oil Addition

The FS-10 A/C compressor (19703) uses a unique high-quality refrigerant oil (F2AZ-19577-AC), Motorcraft Part Number YN-12B or an equivalent refrigerant oil meeting Ford specification WSH-M1C231-B. It is extremely important that only the specified type and quantity of refrigerant oil be used in the FS-10 A/C compressor. If there is a surplus of oil in the system, it will circulate with the refrigerant, reducing the cooling capacity of the system. Using too little oil or oil not meeting the Ford specification will result in poor lubrication of the A/C compressor.

When replacing a component of the refrigerant system, the procedures in this section must be followed to ensure that the total oil charge in the system is correct after the new part is installed.

When the A/C compressor is operated, oil gradually leaves the A/C compressor and is circulated through the system with the refrigerant. Eventually, a balanced condition is reached in which a certain amount of oil is retained in the A/C compressor and a certain amount is continually circulated. If a component of the system is removed after the system has been operated, some oil will go with it. To maintain the original total oil charge, add oil as required to the new replacement part.

The procedures for replacing oil are as follows:

During A/C Compressor Replacement

NOTE: The suction accumulator/drier (19C836) and orifice tube should also be replaced when the A/C compressor is replaced.

A new service replacement FS-10 A/C compressor contains no refrigerant oil. Prior to installing the replacement A/C compressor, drain the refrigerant oil from the removed A/C compressor into a calibrated container. The shaft should be rotated about six to eight revolutions while pouring the oil from the ports. This effectively empties the A/C compressor of oil.

1. Obtain a clean container that can also be used as a measuring device.
   

1. Place the disc and hub assembly on the compressor shaft so the shaft can be rotated.
   
   • If the amount of oil drained from the old A/C compressor was between 85 and 142 ml (3 and 5 oz.), pour the same amount plus one ounce of clean Motorcraft YN-12B refrigerant oil into the new A/C compressor.
   • If the amount of oil that was removed from the old A/C compressor is greater than 142 ml (5 oz.), pour 142 ml (5 oz.) of clean Motorcraft YN-12B refrigerant oil into the new A/C compressor.
   • If the amount of refrigerant oil that was removed from the old A/C compressor is less than 85 ml (3 oz.), pour 85 ml (3 oz.) of clean Motorcraft YN-12B refrigerant oil into the new A/C compressor.

R-134a Refrigerant Oil

CAUTION: Do not add R-12 refrigerant oil YN-9 to an R-134a system. Also, do not add R-134a refrigerant YN-12B to an R-12 system. These two refrigerant oils are not compatible and mixing the two could result in A/C system damage.

The refrigerant oil used in an R-134a refrigerant system is a polyalkylene glycol (PAG) oil meeting Ford specification WSH-M1C231-B or equivalent. This type of refrigerant oil, Motorcraft YN-12B, was made especially for R-134a A/C systems and is not suitable for use in R-12 systems. Never use an R-134a refrigerant oil in an R-12 system.

R-12 systems require the use of a mineral-based refrigerant oil with special additives. This refrigerant oil is known as YN-9. This refrigerant oil was developed for use in R-12 systems only and is not suitable for use in R-134a A/C systems.

During Component Replacement

When replacing other components of the air conditioning system, measured quantities of the specified refrigerant oil should be added to the component to ensure that the total oil charge in the system is correct before the system is operated.

Clean refrigerant oil should be poured directly into the replacement components as follows:

• A/C evaporator core (19860) (19860): add 90 ml (3 oz.).
• A/C condenser core (19712) (19712): add 30 ml (1 oz.).
• Accumulator: drain oil from removed suction accumulator/drier. Add same amount plus 60 ml (2 oz.) of clean refrigerant oil to new accumulator.

Other Refrigerant System Components

If any other component such as an A/C evaporator core orifice (19D990) or a hose is replaced, 59 ml (2 oz) additional refrigerant oil is necessary unless a hose bursts with a fully charged system. Then, the addition of refrigerant oil will be necessary with the amount to be determined by the technician. The suction accumulator/drier should also be replaced under these circumstances.

Are you having a shop install the refrigerant? Check with your computer which type pag oil you need for sure and definitely choose some with dye or add dye! Will save you so much time later. I vacuum and flush twice when I do conversions on older vehicles, you should see the snot that comes out haha.

The condenser can be flushed out manually ahead of time while system open and I would also power wash any and all road debris and bugs out of it.

Retro fit kits usually use Ester oil. It plays nice with any old r12 oil left in the system. You pull a vacuum, throw it in and go. If you are going to clean and flush the system of all the old r12 oil, then you can use the PAG oil.

Stay away from those variable tubes.You will be replacing it with a normal tube in 2 weeks when it sticks.

like said, don't put the variable tube in...it WILL stick.

That truck wont need anything fancy to get cold air....

I really appreciate all the informed replies. I got really busy with work and life to sit down and respond until now. It sounds like the variable orifice tube will very likely be problematic, so I'll stick to the orange fixed. The blue variable one came with the kit from Rock Auto.
With the oil, I thought I'd flush the remaining old parts in the system, and not sure I'd get all traces of old mineral oil out, thought it would be safer to use the estor oil. Which also happens to have the dye in it.
Will try to clean the evaporator like you all have recommended. I can only imagine the crap that's accumulated down in the box, although I've never tackled cleaning out the heater evaporator air box.
Adding the oil to each part sounds great and although I haven't had a chance to reread all those pages of documents over again, some referred to the '96 year. Would it be the same amounts for my '93? (old style condenser) I got a fx-10 compressor.
I will adjust the low pressure switch if it's recommended, didn't know about that.
I'll be doing this work myself. Had the r12 evacuated a while back. worked some on r12 systems in the past, but this is my first conversion to r134a.

How far are you from me? I can do the final vacuum boil and refill for you (free, just pay for the refrigerant) if you want so you can charge system rightwright no air and pull in ester oil instead of the cans

The only item significantly different on a '96 vs yours is the condenser. Your condenser may be ~10% smaller so maybe a smidge less oil kept in it.

Danielle said:

How far are you from me? I can do the final vacuum boil and refill for you (free, just pay for the refrigerant) if you want so you can charge system rightwright no air and pull in ester oil instead of the cans

Click to expand...

If he pours all the old r12 oil out of the compressor, I would be afraid of running the compressor dry before the cans of ester got to it. If he pours the r12 out, he should pour the ester in the compressor before he takes it to you for a charge I would think.

Another example of how just going to Walmart and getting a conversion kit, pulling the remaining r12 out and just putting the ester/gas conversion cans into the system just works.

True, or come here with no belt haha

franklin2 said:

If he pours all the old r12 oil out of the compressor, I would be afraid of running the compressor dry before the cans of ester got to it. If he pours the r12 out, he should pour the ester in the compressor before he takes it to you for a charge I would think.

Click to expand...

This is the right way to do it.

franklin2 said:

If he pours all the old r12 oil out of the compressor, I would be afraid of running the compressor dry before the cans of ester got to it. If he pours the r12 out, he should pour the ester in the compressor before he takes it to you for a charge I would think.

Another example of how just going to Walmart and getting a conversion kit, pulling the remaining r12 out and just putting the ester/gas conversion cans into the system just works.

Click to expand...

The compressor wont be running with no charge in the system......

But to be sure, just unplug the electrical connector at the compressor.