AC Orifice Tube

[70GMCer]

I am starting to get together the parts needed to bring back to life the AC in my 83.

It looks like the system had already been converted to 134 as there are the correct manifold connectors present, but I'm going to replace the orifice tube.

I need to know if the orifice tube for the R134 is the same as R12.

If not, anyone have the part number of the tube I would need?

I'm going to be replacing the dryer, hoses, evap unit & condenser as well as installing a Sanden 508 type compressor.

[v30crewcab]

it will work with the stock one, but a slightly smaller orifice works better. stock is .072. a 38621 is .067, or a 38635 is .062, which is what I am running in my truck. With the sanden I would run the .062 it will work great.

[70GMCer]

Originally Posted by v30crewcab

it will work with the stock one, but a slightly smaller orifice works better. stock is .072. a 38621 is .067, or a 38635 is .062, which is what I am running in my truck. With the sanden I would run the .062 it will work great.

Where did you get yours?

Never mind....found it....thanks.....

[Jeepwm69]

Originally Posted by 70GMCer

I'm going to be replacing the dryer, hoses, evap unit & condenser as well as installing a Sanden 508 type compressor.

You replacing an R4?

Where are you getting your replacement components?

[70GMCer]

Bought all the replacement parts from Rock Auto & eBay

[DieselSJ]

They are color-coded by size. Get the blue one.

[Woodyboat]

Originally Posted by 70GMCer

I am starting to get together the parts needed to bring back to life the AC in my 83.

It looks like the system had already been converted to 134 as there are the correct manifold connectors present, but I'm going to replace the orifice tube.

I need to know if the orifice tube for the R134 is the same as R12.

If not, anyone have the part number of the tube I would need?

I'm going to be replacing the dryer, hoses, evap unit & condenser as well as installing a Sanden 508 type compressor.

You just stated here that you're replacing the DRYER? If your system uses a dryer, I don't believe it will use an orifice tube. Instead, a system with a dryer uses an expansion valve that will be near the evaporator somewhere under the dash...I think.

A system with an accumulator will use an orifice tube. I'm not totally sure that I'm correct on this but I feel pretty certain that I am. One problem is that there is SO much MISinformation out there that it's really difficult to know what you have, how it's supposed to work and so forth. I honestly believe that the industry does NOT want DYI folks like us fooling with their AC systems when so many mechanics have spent thousands of dollars on machinery to reclaim refrigerants and so forth. It's such a huge profit margin for them too.

Here is one very important lesson that I've learned by working with the AC systems on my cars and trucks: DO NOT BUY A REMAN CONPRESSOR! THEY ARE WORTHLESS! Spend a few more dollars and get a brand new compressor. It's not important how I know this.

[SunSoaked]

Originally Posted by Woodyboat

You just stated here that you're replacing the DRYER? If your system uses a dryer, I don't believe it will use an orifice tube. Instead, a system without a dryer uses an expansion valve that will be near the evaporator somewhere under the dash...I think.

A system with an accumulator will use an orifice tube. I'm not totally sure that I'm correct on this but I feel pretty certain that I am. One problem is that there is SO much MISinformation out there that it's really difficult to know what you have, how it's supposed to work and so forth. I honestly believe that the industry does NOT want DYI folks like us fooling with their AC systems when so many mechanics have spent thousands of dollars on machinery to reclaim refrigerants and so forth. It's such a huge profit margin for them too.

Here is one very important lesson that I've learned by working with the AC systems on my cars and trucks: DO NOT BUY A REMAN CONPRESSOR! THEY ARE WORTHLESS! Spend a few more dollars and get a brand new compressor. It's not important how I know this.

I think you're correct. I was wondering about that too. I'm currently swapping in a Vintage Air Surefit system in place of the OEM in my 85. There is NO orifice tube included or mentioned in the kit or instructions. And like you said, there is a " mushroom shaped" copper or brass valve thingy with a copper capillary tube coming out of the EVAP case.

[Woodyboat]

Yup, that mushroom shaped copper/brass thingy is the Thermal Expansion Volvo. ...er VALVE. LOL It's often just shortened to TXV. The capillary tube will have a bulb on the end of it that gets fastened up against one of the lines of the evaporator. It's really important that that bulb makes a very good contact with the tube that it is fastened to. I have always used a small hose clamp on it to make sure - which is way better than whatever I've ever seen any factory use. Anyway, it just gets attached to the side of the tube so that it can sense the temperature and adjust the TXV accordingly. So, go get yourself a little hose clamp... unless of course, it's already connected for you.

[70GMCer]

Some ac systems had a POA Valve or "Expansion Valve". My 83 has the "Orifice" that goes into the liquid line prior to the "Evaporator" to meter the refrigerant. The "Dryer I refer to is a dryer/accumulator that is attached to the outside of the Evap Box. The Vintage Air systems have "Expansion Valves" in their systems & their dryer/accumulator is attached to the Condenser....

[Woodyboat]

Ok, I just went to the Vintage Air website and had a look. In the photos (at least for the system they show for MY truck - an '86 crew cab) they show the dryer mounted to the condensor. This is definitely then a TXV system and not one with an orifice tube and there is no accumulator. The Thermal Expansion Valve is mounted inside the under dash unit and it's already fitted for you. You won't have to do anything else. Yayyyyy!

By the time a man would go out and buy all the replacement parts to revamp the original factory system, he would only be a few dollars away from Vintage Air's entire kit. I can tell by experience that their prices seem really reasonable - especially if you're upgrading a truck that has never had factory air.

[v30crewcab]

I just spent 75 on custom hoses, 150 on a new compressor, and 35-40 for a accumulator and orifice. not even close to a vintage air system. I have over 1200 in my vintage air system in my 53 belair.

[SunSoaked]

Originally Posted by v30crewcab

I just spent 75 on custom hoses, 150 on a new compressor, and 35-40 for a accumulator and orifice. not even close to a vintage air system. I have over 1200 in my vintage air system in my 53 belair.

True, but, keep it a fair compareson. A complete kit is around $1300. The EVAP itself is 750 of that. I swapped everything under the hood intending to keep my factory EVAP and controls. When I got to that point a week ago I had second thoughts when I began trying to hook up 30 year old parts to my new, modern vintage air parts. I decided not to half-ass it so I bought the EVAP kit. Soooo glad I did! Now I have a completely new system from end to end. I must have yanked 100 pounds of vacuum lines, wires, old brittle plastic connectors and spaghetti ducting, cables, etc out of there!

It's now simple, clean, insulated, and hopefully works as good as it looks. In my case, I plan to keep the truck forever and it's supposed to be 115 degrees here today!!! I think the price will be worth it. I

[70GMCer]

I bought a new Evap, Condenser, Sanden 508 Compressor & compressor brackets, orifice tube, dryer/accumulator and I'm into it for $450.00

I haven't bought the AC lines yet, but I figure about another $100.00

When all done, I'll have a new system for around $550.00

[70GMCer]

Rock Auto Four Seasons 54275 Evap $53.79
Four Seasons 33204 Drier/Accumulator $13.75
Spectra 73642 Condenser $72.79
Four Seasons 26739 O-Ring kit $3.83
10% discount $7.21
Shipping $16.98

Amazon Four Seasons 38635 Orifice Tube $5.61 free shipping

Ebay Sanden 508 Compressor $119.00 free shipping

Summit Vintage Air Side-Mount Compressor Brackets 151370-BCA $101.00 freeshipping

total $493.96

[hatzie]

Originally Posted by 70GMCer

I bought a new Evap, Condenser, Sanden 508 Compressor & compressor brackets, orifice tube, dryer/accumulator and I'm into it for $450.00

I haven't bought the AC lines yet, but I figure about another $100.00

When all done, I'll have a new system for around $550.00

You know these don't have dead insects, mud daubers, and old mineral oil that turned to shellac inside em.

[SunSoaked]

Ok I got a question. Why don't my V/A kit use any hardlines? It's hoses, 100%. I'm assuming technology has evolved and the hoses don't collapse on the suction side? Or, is it a durability issue on mass produced vehicles?

[70GMCer]

Originally Posted by SunSoaked

Ok I got a question. Why don't my V/A kit use any hardlines? It's hoses, 100%. I'm assuming technology has evolved and the hoses don't collapse on the suction side? Or, is it a durability issue on mass produced vehicles?

I think it has a lot to do with production costs.

There are so many different hard lines out there, it would not be cost effective for an aftermarket company to make them.

Even the Vintage Air I installed in my 63 Impala has all rubber lines.

[Woodyboat]

Yes, and if you think about it, hard lines are made for production cars that have their routes already mapped out. All rubber lines can be very flexible making installations in a variety of vehicles possible. Interestingly, the mobility van that I use to carry my parents' wheelchairs has a front and a rear AC. From the compressor back to the rear, all the lines are rubber - no hard lines at all.