A/C Orifice Tube and Recharge..

[artrenee10]

Hi all...
Newbie here and an armchair mechanic LOL...

Anywhoos, I have a 1997 Chevy Tahoe, no rear a/c. I need to change the orifice tube. However, where exactly is it? I dropped the front of the truck (grille etc) and there are two tubes, one upper and one lower. Which one is it? Also, how can I get the actual line off without mangling it. Seems to be on there pretty good. Finally, which port does the refrigerant go in on top. Is it the one leading to where the refrigerant label is or the one leading to the front of the car.

its 91 here in Chicago, and I have identical twin boys....

[j cAT]

Originally Posted by artrenee10

Hi all...
Newbie here and an armchair mechanic LOL...

Anywhoos, I have a 1997 Chevy Tahoe, no rear a/c. I need to change the orifice tube. However, where exactly is it? I dropped the front of the truck (grille etc) and there are two tubes, one upper and one lower. Which one is it? Also, how can I get the actual line off without mangling it. Seems to be on there pretty good. Finally, which port does the refrigerant go in on top. Is it the one leading to where the refrigerant label is or the one leading to the front of the car.

its 91 here in Chicago, and I have identical twin boys....

I would have a pro do this..

[bowhuntrrl]

You will need to evacuate before you do this. On my '98 LT w/rear air, the tube is in one of the lines in the engine compartment on the pass side. There is a square crimp on the line that holds it and a double nut connection right behind it.

[MT-2500]

Rear air can be knocked out by a low R-134a charge.

Have you got a leak some place?

What is the low and high side presser readings at idle and at 2K with compresser running.
Post back pressure readings before and after recharge.

[brcidd]

Is your failure mode that you have rear a/c system with no cooling in the rear? or you telling us you don't have a rear a/c unit as part of the details of your diagnosis?

Number one cause of no a/c is loss of refrigerant due to a leak- look at the "belly" of your compressor- is it oily/greasy-- if so, that is probably where you are leaking from-

The recharge port is on the suction side pipe- that leads to compressor from firewall--

Why do you want the orifice tube? Is your discharge pressure excessive?
or do you want to see if it is clogged? Loss of refrigerant does not usually clog OTs-

If you have a non-functioning rear system- it has an expansion valve (TXV) at the rear evap inlet, that may be stuck - it does not use the front systems OT.....

please elaborate...