Humor in an air conditioning system? (560SEL)

[hbofinger]

So I filled up with R134a (converted system about seven years ago, done properly, all seals, new compressor, replaced expansion valve), the car sat for a week as I redid the fuel sending units (new check valves, new filter, new accumulator, etc), and as I drove the car I realized I had no A/C.

So this morning I shot in another can of 134a, and a can of dye. Started looking around all of the usual suspects, but could not find the leak. Below the dash - no trait. So not the expansion valve. Around the compressor - nothing. Around the receiver/dryer - nothing.

So I shrugged a bit and fished out the blue valve cap that goes over the low pressure outlet valve. Except that valve was neon yellow. In fact, everything around it was neon yellow. As looked closer at the valve, I saw bubbles of yellow doming out of it! And yellow, like lava, was dripping around everywhere!

Obviously I am in luck - if you want any part in the A/C to fail, this is the one. Cheap, and easy to get to.

But technically, this would be cracking the system open. I would have to vacuum, and all that, And replenish the oil. No problem - I can do that.

Now I have a question: Would this also mean replacing the receiver/dryer (I have a spare)?