Here are some pictures:

The vent solenoid is a rubber/magnetic shaft spring loaded in the solenoid. The spring applies pressure to the rubber shaft to seal the vent hole in the dryer assembly.

The ASM activates the vent solenoid w/ 12V (based on "12VDC" listed on solenoid) to retract the shaft into the housing - I bench tested and the shaft wiggles slightly downward upon applying 12V. (not sure if this is normal operation) I would imagine so as it wouldn't take a lot of movement of that shaft to get the air to vent out.

This is from my 2nd hand unit. Upon inspection I found the white flaky stuff was kind of binding the shaft from retracting into the solenoid housing.

To save time - I removed the vent solenoid from my original unit and fitted. (This is held with 2 torx bolts. (Don't over tighten... haha...)

Not sure if the rust would play a part in operation (doubt it) but this would mean there is/was moisture in the system at some point that wasn't properly "purged". I guess this could happen if the vent solenoid is rendered non-operational.

As far as the comprssor dryer side - the white flaky specks were evident here as well. A simple blowing out w/ compressed air took care of that.

So, If you get the B2810 code - might be worth removing the vent solenoid (easily accessible with compressor mounted to car) and check it out for build up and clean it and blow out the dryer side w/ compressed air.

Also a good idea to clean the harness side with a quick shot of electrical contact cleaner, let dry and a dab of di-electric grease. (one of my connections looked a tad dirty.

But since the B2810 worked itself out with the vent solenoid swap - I'm leaving well enough alone... until the compressor performance degrades then it will be time to swap over the Andy's ring fix (2nd hand compressor is working just fine - very quiet and raises the struts very quickly)

In the meantime - I need to go back to the seller and report the bad news on his part to see how they will compensate me for this issue and I plan on trying to fix the thread issue on the original compressor.

Happy Holidays!

Anthony

 

I thought I would add some more findings today.

On a hunch - I decided to check the front struts, valve block and reservoir air line fittings today w/ a soapy solution.

So, the good news - both front air lines not leaking...

The bad news - I have air leaking from the fitting with the 2 notches on opposite ends. (I attached pictures) I'm not surprised as the previous owner installed tire air fittings to manually fill each front strut.

When I removed the valve stems these fittings came out too. I tightened them the best I could when I initially re-installed the air lines, nuts and olives. (DOES anyone know the tool needed to tighten the round connection with notches on opposite ends under the line nut???)

Onto the line block and reservoir - started the car, sprayed soapy solution on all the block and reservoir fittings. No leaks, but I thought I saw very minor air bubbles at the line connection on the reservoir side.

I went to tighten that connection ever so slightly - BAD move... the leak became worse. Had to cut the line (with a razor and a block of wood) and install a new nut and olive - no more leak...

Onto the compressor (ugh...) anyway, last night I started the car for the wife to show her how the air suspension works. The joke was on me. C2302 and despite the car being off the stops (only the front struts were depleted) the "vehicle too low" message was still illuminated on the dash.

Needless to say I was pissed....in WDS there is actually a test to see if the compressor is working as intended. (To recap - I installed the 2nd hand compressor as is) So, today, I ran the test - air suspension diagnostic guide states if it takes more than 3 mins for the compressor to fill the reservoir - the compressor is highly suspect... (despite this compressor putting out 7 - 8 BAR) it took several runs of the compressor (including cool down time) to partially fill the reservoir - I stopped the test after 4 minutes of the test initializing.

As Andy suggested - I swapped out the air dryer assembly from the 2nd hand unit (which the spring was very rusted) to my unit with the BP ring fix. Tightened everything up - including the air line and didn't over-tighten this time... depleted the rear struts via WDS and started the car watching the line pressure via WDS.

Before swapping the air dryer/vent solenoid between units I hooked up my original unit w/ partially stripped threads and it worked! (but I felt it necessary to have security at that line fitting so I swapped out the air dryer as mentioned)

Line pressure at the block went from 2 BAR to between 7 to 8 BAR (I know there was residual pressure in the reservoir) but the rear struts both went from -80 mm (fully down on stops) to +2 mm within 60 seconds!

Haven't seen the car rise so quickly...

Yes, I made more steps for myself by extensive troubleshooting, swapping parts, etc - but this was a true learning experience for me.

I reached out to the seller of the 2nd hand compressor unit and reviewed all that was wrong w/ the compressor he sold me (including pictures) he offered me a very sizable refund which I accepted..

And PS - I got my hands on a guillotine style tube cutter in case I have to cut any other air lines in the future (hopefully NOT!)

I hope my adventure in the X350 air suspension helps others...

My learnings:

1) Check all air line fittings w/ soapy solution before meddling w/ the compressor.
2) Install the ring properly in the piston.
3) Thank goodness for WDS...
4) Disconnect the battery before disconnecting any connections in the air suspension system (or anything for that matter)
5) Never over- tighten any air line fitting. Over tightening will surely ruin the air line connection prompting cutting the air line to get a new section for the olive to grab onto.

My apologies for the long winded post...