An expansion valve and orifice tube are two different things dude. He's here asking for help from people with more knowledge, not asking for a preacher. There is nothing illegal about working on an a/c except venting freon into the atmosphere. I don't know where you shop but you must not make much money because the tools aren't expensive.

 

Expansion valves (blocks) and orifice tubes are different but they do the same thing, seperating the pressure from low to high. His truck has an orifice tube.

It sounds like you have a pressure issue, which is impossible to diagnose without a proper measurement. You need a set of accurate gauges, my set was around $150. Im curious as to why the compressor is cycling but you arent getting any cold air. If the compressor is running, but not quick cycling then you should atleast have enough charge to cool the air atleast until the pressure builds too high.

Get some gauges and give us some readings and we will be able to help more.

 

It seems this is directed at me. Thanks for confirming what I said, and I know he has an orifice tube. I just installed a/c on my non a/c truck.

I don't see how he is having a pressure issue, his pressure is good on the low side. You can tell a lot with just the low side gauge, but yes you can tell more with both. You can get decent gauges for around $60ish, but I get by just fine with the low side only so far. His compressor is cycling but no cold air because he didn't vacuum the system and air doesn't transfer heat like the freon that's supposed to be in there.

 

I wasnt trying to be nasty, I was just trying to explain it to the masses. If he has too much air in the system then it either wont take a proper charge or the pressure will be too high. Im not disputing he has air in his system, Im sure he does, I just believe he has other issues.

Theres no way to diagnose it without knowing what his pressures are. "Midway in the green" isnt an accurate reading.

Maybe he has 50psi on the low side? But what if he only has 50psi on the high side? No way of knowing.

 

I didn't really think you were trying to be nasty, I just had to let you know that I knew his was an orifice tube system. If he turns off the system the low will come up when the pressure balances out so he can sort of check for proper freon level that way. I would go ahead and change the orifice tube, it's only $2. Your input is appreciated, I don't know everything.

 

Where is the oriface valve?

 

In the high-pressure side (it actually defines the end of the high-pressure side,) immediately before the evaporator. It's a small thing installed inside the plumbing -- you can't see it without disassembling the plumbing leading into the evaporator.

As far as special tools are concerned, there aren't many:

• Gauge set -- $49.95 at Harbor Freight
• Spring-lock coupling tools - about $10 at any auto parts stores. These are also used to disconnect fuel couplings.
• vacuum pump (many auto part stores will loan you one -- Auto Zone will.)
• themometer -- $2 at auto part stores. Used to measure the temperature of the air coming out of the vents.
• Orifice Tube Wrench - $10-15 at any parts store or online

So for about $85 (and probably less,) you can get all the special tools you need.

Oh -- and buy the Haynes book on auto air conditioning.

This ain't rocket science, guys...

 

The orifice tube is typically in the line going from the dryer/receiver to the condensor. It will be right after the line connects; look for small impression or crimp in the line, thats where she is, and they can be a pain to get out sometimes!

 

Ummm. I have a chilton for my truck. I havent looked in it to see if it has anything about the ac system... but i will

 

It's inside the line that is held together only by that cheap *** plastic clip, right by the a/c box. Seems an unsafe type of clip for the a/c system, but I didn't make it. The system needs to be empty too, I sure hope you knew that already. I used a small pair of needlenose pliers to pull out the tube, but I still had to grind them down to fit inside the pipe.