Orifice tube location

WPHARDING

MEMBER
1997 BUICK RIVIERA
6 CYL
FWD
AUTOMATIC
220,000 MILES

Where is the orifice tube located on a 1997 Buick Riviera (not S/C)? I see two ports (one is larger than the other). I am assuming one is the high pressure port and one is the low pressure port (but they are both in the same line, is that correct?). There is a connection of the line between the two ports, and my guess is that the orifice tube is in there, but I don't know for sure?

6 Replies

WRENCHTECH

MECHANIC
20,761 POSTS

They are both in the same line because they are separated by the orifice tube. That is the point where it changes from high to low pressure. The tube will be between the 2 ports. You will see the dimples in the line that hold it in place.

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Friday, August 12th, 2011 AT 4:29 PM

WRENCHTECH

MECHANIC
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I just double checked the location on this one. I don't know where you are getting the impression that both ports are in the same line because according to the service manual, the tube is in the condenser outlet on this one.

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Friday, August 12th, 2011 AT 4:32 PM

WPHARDING

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I don't know that they are both in the same line, that was part of my question. I know that there ARE two ports in one of the lines. One of them is smaller and one is larger (but they are both shaped the same and have the same type of plastic cap). They may both be low pressure ports (just different sizes), I don't know.

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Friday, August 12th, 2011 AT 5:49 PM

WRENCHTECH

MECHANIC
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One is just a factory fill port.

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Friday, August 12th, 2011 AT 6:21 PM

CHARLES W

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1 POST

The two ports are both in the same line on my 1997 Riviera. My gage set has the large red fitting for high side and smaller blue one for lower. On my other cars, the red coded fitting is the one which gets hot while other line gets cold. On these other cars, the conventional tubing size of the suction (blue) line in larger than the pressure side tubing. The AC on the Riviera is not performing well. Is the orifice tube the likely problem?