Well, the good news is I finally found the really small leak in my brake system that had me topping up the fluid about every 10,000 miles.
The bad news is that I found it is the PCRV that's bolted onto the fender below the fluid reservoir. The source of the leak became obvious yesterday when it became a larger leak!
Apparently, the design is such that it will slowly extrude the O ring seal inside causing fluid to escape.
Of course, I found this as I am preparing for a 2500 mile trip South for Christmas next week......
The new part is on order, but will probably not arrive in time, so the question is:
Can this be repaired?
Seems like if it has an O ring that has an issue, it can be rebuilt?
Anyone done this? Know what the O ring size is??
Cheers.

I have not checked to be sure, but suspect the pin carrying +12v is on the corner of the field.
The metal shell is, of course B-. The slightest misalignment at the critical instant will have the
case grounded, and that pin in contact thus an "STS" moment (Something touched Something)
The tiny spark is just a courtesy to let you know you need a new fuse!

Good Grief!
"Mr Prosser" is alive and well! :)
The inmates are really running the asylum over there.
Logic is gone and blind faith in flawed data systems are becoming the norm it seems and
"common sense" ....Isn't!

I know it's only a matter of time before this spreads across the ditch.
Be afraid......Be very afraid!

Ahhh,
Well, I am glad I mentioned my trials with it, it seems I am not alone!
Cheers!

Yep!
I discovered this whilst being lazy.
Sitting in drivers seat (LHD) when the Nano would lock up such as switching off engine whilst looking at eas values,
I would unplug the cable from it rather than getting out, walking around and cycling power by unplugging the OBD cable.
it did not seem to matter how carefully I tried to re connect the cable, something would touch something, and I would need a new fuse!
Leaving the cable firmly clamped on is a good policy!!

If you unplug the cable from the side of the Nano, at least for me, it will short the power pin when plugging it back in and blow the fuse almost every time!
Maybe just my bad luck, but I stopped unplugging the cable from the Nano and just do the contortionist act to get the plug in under the dash.
+1 on leak being at the Pollen filters or plenum. It does not take much of a leak and if the filters are wet, it works like a swamp cooler to humidify the incoming air!

I have tried 3 different known to be good relays. Same result.
Will dig into it further today.
I am going to look at pin 8 on the EAS controller to see if the signal comes and goes

I can hear the compressor when it's running, and see Nano from where I have my finger on the relay to feel it click in.
The pressure switch is not changing state according to Nano.
Relay ~randomly~ cycles the pump but pressure switch stays open until the system gets to pressure, then switch closes, and compressor is commanded off.

This issue has been going on for some time now, and I am at a loss as to whats going on!
Both my '99 and '02 do the same thing.
When the compressors are running, they "short cycle". By this, I mean they turn on and off in bursts of 15 seconds to a couple of minutes.
Looking at the compressor state on Nano, it shows compressor as "ON", and thermal switch as "NORMAL". It will do this from
stone cold, so not a thermal issue.....
I have several good compressors here, and they all do the same thing, so not the compressors.
The compressor relay is new, and it does cycle on and off with the compressor, so it is getting a signal to switch on and off.
If I wait a few minutes, the system will get up to pressure and the pressure switch will change state shutting off the compressor as it should.
I am looking at the EAS ECU, and I suppose the MosFet driving the relay is possibly thinking it is overcurrent and folding back the output? Looks like pin 8 from the ECU has that signal....
This is no major deal except that when the missus is doing short trips to the shops, it will eventually come up with an "Unknown Fault"
and go to extended height whilst flashing all 4 lights on the EAS switch. Probably finally runs out of air??
While I am at it, has anyone come up with an answer from Colin and his merry men about why the Nano displays an EAS fault as "Unknown"??? It can clear it fine, but not knowing why it faulted does not assist in troubleshooting!. Annoying, at best!

Where did he find it for that price?
The recovery website lists the 2 versions at $715 and $1625 Aud......
A bunch more than nano....
I was going to recommend one to my mate in Vic for his L322......

If you do a Google search for "exhaust pipe clamp" You will find several types.
I have used the U bolt version and the wrap around flat strap type both with good results.

Remember: If it sticks, force it. If it breaks, it needed to be replaced anyway.

+1 on adjust it yourself.
I just did a new ball joint end on the Pittman arm. Adjust it by leaving the pinch clamp loose, and driving a bit on as flat a road as possible (no crown), pulling over, tweaking the adjuster a few times in whichever direction is necessary (trial and error), I was able to get the wheel spot on. Took about 15 minutes.

Sorry, I realise that this is a bit of tail chasing, but when you went into Nano to manually switch on the compressor, did Nano report that compressor was already on? I am guessing it said off.
Next time it does this can you write down the status of pump, pressure switch, and over temp switch before you change anything?.

It could still be an intermittent pressure switch or, less likely, the temp sensor.
Although, I would think that if either of those were bad, the ECU would not allow the Nano to turn on the pump?
Of course, intermittent faults are a bugger to track down, which is why I am asking previously answered questions......Looking for you to catch a different reading.

If, when you switch on the pump with Nano, as you said, the suspension immediately begins to rise, and stays up, I am thinking that the compressor is fine.
Mine was doing much the same thing, and it was a faulty relay. It could be an intermittent connection on the PCB of the fuseboard as well. They do fail.

Hmmm....Don't park in Dorking?

Has anyone ever been able to get Collin and his merry men at BBS to tell us what an "Unknown Fault" is?
I get them whenever either of mine throws a wobbly. Clear them and all good again. It's nice that it tells us that there is a fault, but useless for diagnostics. What does RSW show these faults as?
As for somewhere else to look, Have you confirmed that the plugs on the EAS ECU are clean and tight?
All of the intermediate plugs that the sensor wires run through?

Since you have now had a 4 wheel fault, Is this yet another odd P-38 issue caused by a corroded or loose
earth point affecting the ECU? That could cause all four sensors to mis read.
Have you run through all of the earth points and cleaned them up? This, I have found is practically a basic service for these things and at 20+ years, and in your corrosive environment, could be due.
Bad earth point will cause all kinds of seemingly unrelated gremlins to randomly pop up (Like touch the brake and the radio goes off, and HVAC display blanks out)
Good hunting!

They like to lull you into a sense of false complacency, then strike! (usually on a dark and stormy night far from home)
It should be fine now until you forget to bring the Nano with you.........They know!

Seriously tho' That is an odd one, and I would like to know why they can heal themselves. I have experienced short periods of the same type you have been suffering, and upon closer examination, the issues have cleared up. No cause and effect!
Good luck!

Not such a bad idea. Good quality sensors are getting pretty thin on the ground.
At some point, probably soon, we are going to need something other than the horrid chinese parts.
In the meantime, I am buying any sensors I can get when I visit the breakers. Used OE beats pattern parts
any day for these things.
Just thinking a bit, a small plug to plug module to interface a hall effect sensor and output the voltages
a pot would do should not be too hard? May need to add a hot lead at each sensor to power it?
I agree, the ECU itself rarely gives issues.

Have you got a spare pressure switch you can swap in?

If it is getting down to solenoids acting or not, have you checked the connector to the driver pack beneath the valve block?
Apparently, the pins can become loose over the years causing all sorts of intermittent mischief!
Maybe, if available try a different driver pack?
My tendency is to suspect the pressure switch itself.....
My 02 has tossed an EAS error on the dash and when looking at the error on nano, it is telling me the switch has not changed state or something like that.
I clear the error, and it goes away for months or years......I do have a spare switch in the cubby just in case it is really dodgy, or finally fails.

Fiddled about a bit more in no particular order and pump started running for awhile without doing anything specific.

Fiddled with what, specifically?
Wires? connectors?
Or did you fiddle with nanocom only?
What got wiggled or jiggled?

It's ok to admit at this point that you gave it all a "gentle tap" with a 10 pound sledge hammer........

It could also be a dodgy connection on / in the fuse board.
Is there voltage actually present at the pump when the Nano says the pump is on?
That's how I finally determined I had an intermittent pump relay.
An issue in the fuse board will bring up all sorts of odd gremlins!