I've gone through most of the system but I'm getting stuck on what's going on. In a nutshell, here's what you need to know:

- Turn vehicle on
- Compressor kicks on
- Gallery pressure stays constant
- 5 seconds pass, no increase in pressure according to gallery
- Fault shown (pressure increasing too slowly...but keep reading)

HOWEVER. If I force it to run for a while something will change and the pressure will start increasing normally. The sound from the compressor changes as well; the "tone" or "pitch" of the motor drops as if it's finally operating under a load. Once that happens, it'll cycle on and off without issue. It builds to 255 PSI and stops cycling on and off like you'd expect. Next day, same issue. Piston seal in the compressor was just replaced and the fact that it gets up to 255 psi tells me it's fine in that regard.

My working theory is that the exhaust valve on the compressor itself is stuck open and once in a while the compressor will be able to "pull" it closed with its vacuum, creating a good seal and allowing the pressure to increase.

What else could it be?

 

Could be. The part is like $15 and easy to change. You dont even really have to remove the compressor much, just the intake/exhaust lines maybe then drop it down some. Replace and fire it up before fitting back in place.

 

Awesome, I'll give it a go. I've seen kits that include o-rings and springs for the exhaust valve and cover (here). I've also seen rebuild kits that are just a plastic bit and small spring (here).

Can you help me understand the difference? Or which you'd recommend I tackle first?

 

The first kit is a seal kit for the larger exhaust system under the square flat cap and the smaller exhaust parts under the "bolt" head. The second is probably all you need though.

 

For $20 more - I would just get the more comprehensive kit, since you will have it open anyway.

Have you ever changed the desiccant?
If not, I would highly recommend doing that - along with a metal dryer cap.

 

I changed the canister out last year. But who knows with some of this cheap non-OEM crap.

Pulled the delivery valve last night. Seemed fine. Put it back in cleaned up and same issues coming up.

I'll need to pull the compressor completely off once the kit shows up later in the week to see what the actual valve looks like. While I'm in there I'm going to double-check the condition of the dessicant and filters as well. I'm hoping one of these actually fix the issue. It's starting to really drive me crazy. Diagnostics are the worst!

 

Agreed diagnostics are the worst, especially on the LR3.
Hours of troubleshooting can be common and frustrating - but - often times the fix turns out to be uncomplicated and not too expensive.

. . . Once you find the problem, that is.

Fingers crossed!

 

Im dealing with what seems to me is a signaling problem; compressor dryer rebuilt but still leaking a bit from CAP. NCJ pressings on a 09 L322. From my experience the dryer cap can bleed off and bubble for a. minute but the rear or compressor valve block shouldnt let ANY air past when sitting and seated properly and I rebuilt that too using the 4x4 airseals kit; to be clear I didnt do the rest of the compressor. Exhaust valve will open after compressor runs for like 5 sec then bleed off then start again; motor temps are absolutely fine. Almost feels like a signaling issue but I cant wuite see it on the GAP. To be clear, the FLHS was reversed by previous owner and as a result it was lowering to bump stop on rear right when sleeping; took it off tested fine and installed correctly. Car doesnt really lose height but does a little lowering on rear after shut off; which seems to me to be a leveling attempt and my garage is level. Ive calibrated the heights using the GAP instructed program and theyre within about 1.5cm. Does anyone have range of galley pressures? I can build right up to 220 psi, but then when driving itll pop off and go to 35 psi and remain there; exhaust valve looks linear, everything else looks normal; comparative graphs on HS done they look right. Does not happen except on start up and gallery is still at 35-60 and on hills going up and down; never on straightaway. Id really like to know what gallery values should hover at.
Dave
09 FFRR
12 FFRR

 

EAS DRYER CAP =AZUeH9ypTjyANgTFw72ItABM3KKR0KCTZ6YEXTCh6hfJI3M5o Saj2q4lUl0fFGOGnI0-xoh3g3m7m0NWpafVbhs3FQ6Xl8_OEu1IbQKZUXzRMljcbXuM-kRHP5syVgXEKQ0b1UapTs042uDq-OZc_28O&__tn__=-]K-R]Questions pour un champion (Officiel) I have a ? about the dryer cap that 4x4 air seals offers; they claim it will fit both a hitachi and my NCJ Pressings england EAS compressor in the spare tire section of my 09 L322 which is leaking at the "blue" at the cap end port. However, the fittings on the cap pictured in their ad doesnt show a red and blue connection but two brass connectors; has anyone with an NCJ pressings compressor tried their dryer cap rebuild kit for 33 pounds and successfully fit it to an NCJ Pressings dryer assembly?

Where does one source a metal dryer cap?

Thanks,

Dave

 

Search X8R LR3 on ebay or amazon