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A/C Accumulator and Orfice Tube Change

19K views 10 replies 5 participants last post by  J83 
#1 ·
I had an A/C leak in my 2007 classic Silverado 2500HD Dmax. I used dye and found that it is leaking where the pressure sensor connects to the Accumulator or filter/drier. I am going to replace the Accumulator and the Orifice tube. I have 4 questions.

1. Where is the Orifice tube located. I found an older thread on this but the pics are gone and one person said it was by the condenser while another said it was near the accumulator.

2. Do I need to add oil to the compressor since there was a leak or just refrigerant?

3. How much R134a does the entire system take? I read 1.8 lbs for the 2004. My stick under the hood is no longer legible.

4. A vacuum pump used for R12 can be used for R134a correct?

Thanks for any help!
 
#2 ·
The orifice tube is "in-line". Not sure on 2007, but on my 2002, passenger fender where line breaks apart. (2 lines connected together with "nuts"). You can usually spot where the orifice is by looking for the slightly enlarged diameter of the line near the connection of the 2 lines.

You're probably fine on oil. Most of it stays in compressor and lower points in the system. When draining the system before opening, make sure you just barely crack the valve on your gauges and let it out slowly - so as to keep the oil from spewing out.

Not sure on capacity.

Vacuum pump - yes - but you will need the adapter for R-12 fittings to 134 fittings to connect to your gauges.

I'd also suggest changing the hi side charging port while you have the system down. I've had to change mine twice over the last 14 years.

Bet your leak at the pressure switch is the o-ring or the switch itself.
 
#5 ·
have you changed the cabin air filters? there is no actual connection between the accumulator and the air that is entering the cab. the AC system is sealed, which is why you need the vacuum pump, to smell inside the accumulator you would need to have air from that system entering the cab, which would make it no longer a sealed system.
 
#4 ·
1, i believe its near the front of the vehicle in the line that runs to the condenser but im not positive on that.

2, yes, you will need to add 2 oz or oil if memory serves. i just replaced an accumulator myself. the GM specs for replacement of the part require oil to be added to make up for what oil would be in the old accumulator.

3, 24 oz sounds familiar, but really you should be filling with a manifold and stopping when the pressures are right rather then just adding x amount of refrigerant.

4, as long as the fittings are right, the seals in the pump may or may not be rated for the oil though.


they have pressurized oil cans that fit your manifold gauge set, its MUCH easier then trying to get the liquid in the bottle down the hose if you dont have the oil injector for the line.
 
#7 · (Edited)
1, i believe its near the front of the vehicle in the line that runs to the condenser but im not positive on that.

2, yes, you will need to add 2 oz or oil if memory serves. i just replaced an accumulator myself. the GM specs for replacement of the part require oil to be added to make up for what oil would be in the old accumulator.

3, 24 oz sounds familiar, but really you should be filling with a manifold and stopping when the pressures are right rather then just adding x amount of refrigerant.

4, as long as the fittings are right, the seals in the pump may or may not be rated for the oil though.


they have pressurized oil cans that fit your manifold gauge set, its MUCH easier then trying to get the liquid in the bottle down the hose if you dont have the oil injector for the line.
The small cans of pressurized oil are easy but so is sucking the oil out of a bottle. Once you pull the system down with your vacuum pump, close the valves on the gauges and disconnect from the pump. Now, drop the loose end of the suction hose (charging hoses) down into the oil bottle and slowly crack open the low side (suction) manifold valve. The vacuum in your system will suck the oil right into the system. When you have enough oil sucked out of the bottle, close the valve, attach a can of 134 and charge it up. this works well enough to get the entire oil requirement into the system on a complete flush & rebuild.


And I seriously doubt there will be any appreciable amount of oil in the old accumulator.
 
#8 ·
have you changed the cabin air filters? There are NO cabin filters after 2002 on the truck.
 
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