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2004 Suburban 2500 LB7
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Discussion Starter · #1 ·
Just bought my 2004 Suburban 2500 with a 2002 LB7.

I bought it already swapped and was told the A/C worked as it should. It didn’t…surprise.

Doing a little research, it may seem I have an incorrect line? I only have 1 port and it’s the high side. Looking at pics online, the LB7’s did have a high and low port and they are on the same line.

Should I buy the line with the high and low ports and install it? Or is what I have fine and it can be used as it sits?? I have zero clue.

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2004 Suburban 2500 LB7
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Discussion Starter · #2 ·
Here is a pic off the web of the line I’m thinking should be in my truck.

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Discussion Starter · #3 ·
So after some discussion with a buddy, I think we came to the conclusion that because my Burb has rear A/C, the line is specific for that setup. The truck LB7 obviously doesn’t have rear A/C so the line setup is different.

So, I might buy the truck line setup and see if that gets it to at least be able to have a high and low port? I dunno….

Any experts up in here? 😄
 

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I think the system must have a low side port somewhere. Adjusting refrigerant levels is done thru the low side port as well as monitoring the system's low side pressure.

If you go to GM-based parts websites you may find enough detail to see where that low side port would be. Perhaps you are correct in your thinking and seeing the parts detail would confirm it.
 
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Yes sir give me just a few minutes, it’s raining cats an dogs outside right now! Haha
 

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Discussion Starter · #8 ·
Yes sir give me just a few minutes, it’s raining cats an dogs outside right now! Haha
No rush, sir!!! Lol, whenever you catch a free minute!

We had a freakish random hail storm over us yesterday with 90 degree heat all day. It was wild! Golf ball sized nuggets.
 

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Discussion Starter · #9 ·
I think the system must have a low side port somewhere. Adjusting refrigerant levels is done thru the low side port as well as monitoring the system's low side pressure.

If you go to GM-based parts websites you may find enough detail to see where that low side port would be. Perhaps you are correct in your thinking and seeing the parts detail would confirm it.
Thanks Ron, I’ll give it a look to try and narrow it down.
 

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If @Super gets drowned or something, I can probably grab some pictures tonight. My 02 still has the factory lines on it, though I do need to change the line from the condenser to the compressor and drier- on the 99-02 trucks I'm pretty sure they were all a one-piece line but change to two different lines in 03 I believe
 
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Discussion Starter · #11 ·
If @Super gets drowned or something, I can probably grab some pictures tonight. My 02 still has the factory lines on it, though I do need to change the line from the condenser to the compressor and drier- on the 99-02 trucks I'm pretty sure they were all a one-piece line but change to two different lines in 03 I believe
I appreciate it! All the pics I can get before I start buying lines.
 

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Dont mind those couple ugly hose clamps, I really need to change them- and wash the engine bay. But that is the factory line setup on my 2002. I would be interested to look at a factory line setup on a burb to see if it is different because of the rear ac- I'm sure it is, but maybe they did cobble something together with yours.
 
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OOOHHHHH I just took another look at your first picture- it looks like they combined two lines just on the back side of the fitting there between the fitting and the threaded junction, like they are two different sizes- and I see the line that would go to the rear ac just kinda hanging out there to the left. So I'm gonna guess they cobbled some stuff there
 
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Pardon my ignorance here but how can you have both the high pressure port and low pressure port on the same line? I never paid any attention to my AC ports on my truck. I would expect one line would have the same pressure at either spot. I am no AC expert but my limited understanding of it is the low pressure port is on the "in direction" side of the compressor and then the high pressure side would need to be on the "out direction" side.
 

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Discussion Starter · #15 ·
OOOHHHHH I just took another look at your first picture- it looks like they combined two lines just on the back side of the fitting there between the fitting and the threaded junction, like they are two different sizes- and I see the line that would go to the rear ac just kinda hanging out there to the left. So I'm gonna guess they cobbled some stuff there
Thanks so much for the pics! I think you’re exactly right. Looks cobbled together at that union joint. Yes, the dangling line is for the rear A/C which I’m not so worried about at this point. If I can get the front working like factory, I won’t really need the rear to work.

So I think I’m going to buy and replace that one line and go from there. But before that, I’m going to look over all the lines again and make sure I didn’t miss seeing the low side port at a different location, as someone suggested.

I appreciate you guys!
 

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@RaticalM4 There between the fittings where the threaded joint is, thats where the orifice tube should be- the controlling part of the ac kinda in these trucks. Thats why the high pressure port is on one side and the low pressure port is on the other.

@BOOM_FIST I think if you get the complete line assembly between the condenser and the evaporator, including the orifice tube, you should be in good shape to get the front ac working at least
 

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Discussion Starter · #17 ·
@BOOM_FIST I think if you get the complete line assembly between the condenser and the evaporator, including the orifice tube, you should be in good shape to get the front ac working at least
Yes’sir, I’m on board with that. Now to figure out what that line is called! And find the part number!

Another question, the lines that are directly over the A/C compressor, why does mine look different than yours? Like, what is that dual canister looking deal that attaches to the top of the compressor? Should I swap over to that style line too?
 

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Discussion Starter · #18 ·
Alright, found the lines and part numbers. The more expensive one I’m not sure I need, but I looked at it anyway. The ones that are on my truck now are brand new so I don’t want to replace them if I don’t need to. I think I’m going to order the 19210875 line for sure though.


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I think they are different because your compressor is off an 03 or newer setup-- they changed it after 2002 Im pretty sure. They went from whats on my truck- one single line from the top of the condenser to the compressor to the drier, to the 03-newer design with two separate lines- one from the condenser to the compressor, and one from the compressor to the drier. Just a design change that was probably for better serviceability. If i ever change my compressor, i will probably change it to the updated line setup like you have. And yes, yours looks new so I wouldn't worry about that side of it
 
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Discussion Starter · #20 ·
I think they are different because your compressor is off an 03 or newer setup-- they changed it after 2002 Im pretty sure. They went from whats on my truck- one single line from the top of the condenser to the compressor to the drier, to the 03-newer design with two separate lines- one from the condenser to the compressor, and one from the compressor to the drier. Just a design change that was probably for better serviceability. If i ever change my compressor, i will probably change it to the updated line setup like you have. And yes, yours looks new so I wouldn't worry about that side of it
Matt, you’ve been a gentleman and a scholar! I appreciate your input and knowledge, brother. Thank you.

Just ordered that high/low port line so hopefully that’ll at least give me front A/C! I’ll update this once I get it straight.
 
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