SloopJohnB@mac.com

That pretty much is the layman's terms….it's kind like asking what the layman's term is for a star.
The function of the orifice tube is to provide a pressure drop across a smaller opening that partially blocks the high pressure line from the condenser. The liquid from the condenser expands/vaporizes to the low pressure side of the orifice tube and radically drops pressure/gets colder and goes to the evaporator where it picks up heat, more vaporization, and then gets sucked into the compressor.

The expansion block appears to be that component that contains the orifice tube.
However, the diagram/component terms are somewhat confusing and probably have lost something in translation. I couldn't find the expansion block in the diagram or component terms. You might be better off checking the parts diagram at the dealer or a better parts diagram.

vtraudt

Can someone post a photo or part parts diagram showing the expansion block?

Want to make sure to check it, or have a new one on hand when ripping system apart for rebuild.

SloopJohnB@mac.com

Try google images, looks something like this on a TT:

2002 02 AUDI TT MK1 8N 1.8 T - AC EVAPORATOR EXPANSION BLOCK 1J1820103B - WolfAutoParts.Com

Airbag

im not so sure this car has an expansion block. Did you just take it to a regular AC place or VW / Audi specialist

i ripped apart the AC on my 95 and looked exactly like your picture.

24 is the orrifice tube. They may be considering part #6 the expansion block . if you have it all evacuated currently it is easy enough to take off the connection by the firewall and see if your orrifice tube is plugged up . I got one for 6 bucks at a local AC shop and popped it in.

CRuby

I thought A/C systems either have an orifice tube or expansion block, but not both. Your's has an orifice tube, #24 as shown in your diagram. Tube has a flat plastic end on it, that you can grab w/ needle nose pliers. Pull straight out, avoid twisting cause it can break the plastic. It's only held in place by interference btwn O-rings & tube wall.

Airbag

Now that makes sense ... ours has an orifice tube and i removed it as stated here. Mine was clear as a bell and just replaced it along wit the dryer as i was repalcing the heater core and had it ll apart. the question would be if yours is plugged , WTF is it plugged with and does that lead to bigger questions.

Prospeeder

At the beginning of summer i had a 99 A4 in with non working a/c. Strange readings on the gauges. about 25-30 on the low side and 120 on the high side. No cooling. Ended up being the orifice tube was PACKED with black chunks of crap. I have no idea where they came from or why. But i replaced the Accumulator and orifice tube, and it was ice cold worked great. I suspect the compressor is wearing and the debris is ending up in the tubes screen.

N_Jay

Sounds like "Black Death" common on Hondas and some Fords.

vtraudt

Can't locate the orifice (new on hand).
Can some post/link photo of location, diagram or else help me how to find it so I can change it out.

Also new tank on hand.

Car is 2003 Audi Allroad, but assume all C5 A6 models are the same.

Prospeeder

Its in the small high side pipe heading into the cabin. Remove the bolt holding the 2 lines on the firewall. and then follow the small one towards the engine, and u will see another fitting, remove that. take out the peice of pipe and look inside, theres the tube.