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Help! DIY How to Replace A/C Orifice Tube?

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Old 07-16-2013, 12:13 PM
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Didnt even think to check the condenser coil fins... Ill see how much dirt and grime has built up in the fins.
Thanks for the help with A/C knowledge... This is one area that I know NOTHING about!

Originally Posted by jcman
You might be surprised how much road dirt is in the condenser coil fins, I use purple power and a water hose rinse on mine every two years. As with any refrigeration system it becomes very hard to condense freon over 90 degrees as the capacity drops off hence heat rejection in a rated time frame, "we are not making an area cold we are removing heat from an area"
Old 07-16-2013, 12:39 PM
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Originally Posted by aca6c5
Didnt even think to check the condenser coil fins... Ill see how much dirt and grime has built up in the fins.
Thanks for the help with A/C knowledge... This is one area that I know NOTHING about!
No problem Buckeye member.
Old 07-16-2013, 12:55 PM
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Originally Posted by aca6c5
Didnt even think to check the condenser coil fins... Ill see how much dirt and grime has built up in the fins.
Thanks for the help with A/C knowledge... This is one area that I know NOTHING about!
try and flush the condenser from the back to the front.....bugs come in the front.
You're also flushing the radiator...people don't realize how much stuff collects on it.

IIRC there was at least one Sprint Cup car that had to pit recently because rubber ***** off the track got into his radiator and the car overheated.
Old 07-16-2013, 12:57 PM
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Originally Posted by aca6c5
Well seeing that I have to evacuate the system I might just skip replacing the OT. The reason why I was looking @ replacing the tube was due to when the A/C is on, the air doesnt feel as cool. Sure I could just add some more refrigerant but I saw an article that a clogged OT can cause the same behaviour. When the temps are over 95degrees the HVAC is set @ 72 and the air is not as cool as if its 80degrees out.
That makes no sense...if you have to evacuate the system that is the time to replace the OT and the dryer. You also need to replace the condenser oil but that's another story. Unless you really know what you're doing, replacing the OT, dryer, and compressor oil is one service left to the pro shop.

If you want to evacuate and refill yourself, that's probably ok...you DO have a scale to measure the refrigerant charge, right?
Old 07-17-2013, 05:19 AM
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Originally Posted by jcman
If POE or PAG oil becomes moisture laden sludge will slam the drier and metering devise, the mesh screen can be cleaned with a solvent dip and compressed air, agreed the drier should be replaced if this is the case.

Along with a blown-out compressor one of the most nasty conditions is metal debris jamming the condenser coil causing a pressure drop "system restriction" even after a drier change, I have had to liquid flush backed with compressed air in a reverse method flow to dislodge debris from the entering header of the coil "broken reed valves".

But at this point we don't know what the OP's problem is.
All good points...OP didn't even slap a gauge manifold on it or post the pressures.
Old 08-06-2014, 08:38 AM
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Originally Posted by jcman
The orifice tube is just before the evaporator forward of the mechanical block connection in the high side line "smaller line", loosen the compression block bolts after you evacuate the system and look in the line for a plastic centered tab "orifice tube" that can be pulled out with a pair of needle nosed pliers.

Note: Not all models use a restrictor aka orifice tube some use txv's aka thermal expansion valves.

It would be very rare to replace a OT unless the mesh screen is slammed with debris that can be cleaned and reinstalled, on the other hand if you do have a txv the only reason to replace it would be a dead power element that drives the valve to keep the relative super-heat in line with the heat load of the evaporator.
Can someone phost/link to photo or diagram showing the orifice location on my 2003 Allroad (C5 A6 models)?

I have a plugged system (AC shop diagnosed, super high pressure on high side, even after 30 min vacuum can't get anything in without high side going ballistic (450 psi shuts the compressor off).

Have new orifice and new 'tank' here to insall.
Old 08-06-2014, 09:29 AM
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Found it

2003 A6/Allroad (C5 models):
Where the high and low line go into the cabin, next to the batter, after the high/low nipples/connectors.

Remove the big center Torx screw (forgot: 45 or 50), pull the connector apart. In the high pressure line (thin tube) going to front of the car (not the part going into the cabin) is the orifice tube. You can see a flat black plastic end, grip with needlenoose pliers, turn and pull.
Old 08-06-2014, 11:35 AM
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....and ? was it plugged ? pics ?
Old 06-06-2020, 12:33 PM
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Default What about on a 2006 A6 3.2

Where can I find the oriface tube/expansion valve?
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