How to know if my A/C evaporator has standard, metric or flared threads?

[Zach]

Other than removing the evaporator, is there a way to find this out? I know I can take it out and see, but I'd like to avoid taking everything apart and putting it back together just to find this out if possible. If I do that, then I have to order the expansion valve and disassemble, replace and install again. Wondering if it's something like if the truck is made between this date and that it should have metric, etc.

 

Thanks y'all

[Zach]

Wait, I'm learning more after I wrote this, does the evaporator come straight through the firewall? If so I may have just answered my own question

[Wildcat Walker]

You can look up replacement components on Rock Auto. Sometimes the Info tabs will have what you need, if not, you reach out to manufacturer to ask. This applies to direct fitment parts only. Universal is a whole different ball game. 

 

My question to you, if your system is sealed and full of refrigerant then what are you trying to accomplish? If your system is not sealed or in working order, then just take apart and inspect the fitting of interest. 

 

I do believe the factory AC 720 has high and low side fittings that protrude into the engine bay from the firewall. Your questions seems to be WRT fitting location. Almost all piping for all AC goes through firewall. If you're opening the system, change the drier and get it sealed and evacuated as quickly as possible. 

[Stoffregen Motorsports]

And in case you didn't know, an A/C system that is discharged or has been exposed to atmosphere will need a new drier and a flush. You can get away without the flush if it has been closed up, but it's a safe thing to do. Also, oil. It will likely need oil. New o-rings are always a good idea too. I believe the green ones are R134 compatible, or is it orange...?

 

If you have an A/C shop nearby, it's not that expensive to have them make new hoses and then flush, charge and check for leaks.

[Zach]

1 hour ago, Wildcat Walker said:

You can look up replacement components on Rock Auto. Sometimes the Info tabs will have what you need, if not, you reach out to manufacturer to ask. This applies to direct fitment parts only. Universal is a whole different ball game.

 

Yeah, unfortunately on Rock Auto there are three different kits listed for my truck without any info on what I should use. All with the same compressor, but the expansion valves have different thread types on their three different kits.

 

 

1 hour ago, Wildcat Walker said:

My question to you, if your system is sealed and full of refrigerant then what are you trying to accomplish? If your system is not sealed or in working order, then just take apart and inspect the fitting of interest.

 

I bought the truck with no A/C compressor, so it's not sealed, but I was just hoping to avoid removing the dash to get to the evaporator if possible. I'll do that if it's the only way to find out, but wanted to ask around first before I went to the trouble of removing the dash.

 

 

26 minutes ago, Stoffregen Motorsports said:

And in case you didn't know, an A/C system that is discharged or has been exposed to atmosphere will need a new drier and a flush. You can get away without the flush if it has been closed up, but it's a safe thing to do. Also, oil. It will likely need oil. New o-rings are always a good idea too. I believe the green ones are R134 compatible, or is it orange...?

 

Yeah, I'm just getting a kit that includes a new drier. The one that was on the truck had been sitting exposed for who knows how long, so I'm just gonna get a new one to be safe.

 

 

28 minutes ago, Stoffregen Motorsports said:

If you have an A/C shop nearby, it's not that expensive to have them make new hoses and then flush, charge and check for leaks.

 

Luckily I have a friend with an A/C shop, so will get free freon charge and if new hoses are needed I can get those done fairly cheaply.

 

___

Thanks for the help so far.

[thisismatt]

I would start by seeing what size wrench they take?

 

You should change out the expansion valve also.

[Zach]

1 hour ago, thisismatt said:

You should change out the expansion valve also.

 

Yeah, the kit I'm looking at comes with that too.

 

1 hour ago, thisismatt said:

I would start by seeing what size wrench they take?

 

Nice! If you read my initial question, you'll see that I'm fully aware that I can take out my dash and check what size the threads are. Again, the reason for the post / question is simply because I was hoping to avoid having to do that since it will take some time, and I hoped someone on the forum might know what type of threads my truck is likely to have. The expansion valve is next to the evaporator, so it's not as simple as just grabbing a wrench and seeing what size they take

[NC85ST]

You don’t take the dash out to remove the evaporator. It’s in the black box under the dash on the passenger side. It’s not that difficult to remove, but there are a bunch of clips to remove. The 2 or 3 between the box and firewall are the most difficult.

[Zach]

Ahh ok great! I didn't think it was that easily accessible, thanks! 

[Wildcat Walker]

Add your oil into one of the components before you seal the system and pump it down. You will need to guesstimate that amout of oil you have lost and need to replace, unless you flush out the system and start from scratch. If the system was R12, try to use R12 if you can find it. You will get better performance. Make sure you let the system sit with gauges on it overnight to check for leaks BEFORE you charge. You dont want to waste refridgerant. Hazard Fraught aka Harbor freight sells some decent starter tools if you dont have any. 

 

DO NOT JUST ADD R134A FROM A PARTS HOUSE MINI CAN. 

[builte]

What year is your truck im removing all my ac stuff and if you want it you can have it

[datzenmike]

Nissan switched from SAE to metric back in the late '60s early 70s. Can't see why they would use non metric in the '80s on anything.