Hi All,

So for the past month my 2006 LR3 (4.4 v8, 45K on it) drops to access height over night on the rear air bags, the front bags stay the same. I removed the following fuses per another post: F35P (passenger glove compartment), F3E, and F26E (engine compartment) and let the truck for three days. The truck did not settle even a 1/4 of an inch. So to me it seems like the rear bags/lines are not leaking. Do you think its the rear air valve block (I've sprayed it with soapy water and did not see any bubbles) or could it be a bad rear height sensor?

Thanks for any help!

 

It is probably a problem a problem with the rear Solenoid Valve Block.They can get gunked up from deteriorating air dryer material. I have heard they can be taken off and cleaned. At least in one instance in Australia it worked this way. At least that would be the place to start.

You might also consider replacing your air dryer, or at least taking it off and having a look at the beads and see if they are all clumped up.

 

Cool, thanks for the tip. I'll try to clean it up tomorrow

 

Yes, there may be deterioration of the air dryer desiccant and hence plugging of most likely the rear block valve.

Pulling the fuses proved that there is no mechanical leak within the system so that simplifies finding the problem. The dropping is presumably something to do with the level checking that goes on automatically every couple of hours or so when the 3 is parked.

The auto level program only allows the release of air pressure, hence any attempt at levelling causes something to lower. In your case, it would appear that both rear air springs are being deflated rather than just one of them.

Given that there are no mechanical leaks, the only place air is released in a properly operating system is back thru the air dryer located at the compressor. This is so the dry air already within the system dries out the desiccant as the air is released. It is the front and rear block valves however that allow or deny release of air from the appropriate air spring. The released air then exits back thru the air dryer.

Below is a link to a German website that sells the desiccant material. There are some good jpg's as to what good desiccant looks like. You may discover a powder inside rather than individual beads. It is this powder that escapes the air dryer and then plugs the block valve orifices.

DiscoveryParts - Luftfederung - Kompressor und Lufttrockner - Alles für Land Rover Discovery

 

Thank you bbyer! It sure seems like this is the case in my LR3. I put an order in for a new rear valve. When I'm installing it, I'm going to open up the air dryer and check out the condition of the beads. I know my car came from a high humidity climate before I had it (not sure if that contributes to the beads failing).

 

Keep in Mind the BLUE beads that were used in some units are cancer causing. Do not mess with it, handle it or breath it, etc.

Haven't found a US site yet that sells this, but it only is sold in bulk unless someone like the fellow in Germany buys it and repackages it. Hard knowing the specification for it for sure.

Perhaps someone speaking German can contact him and get some answers. I'd be willing to buy it and put it in smaller batches for folks if I can find it.

 

Did you get this fixed ? What was it in the end ?

 

I have a high mileage '06 LR3. I have to thank TY1 for, as this helped me discover a blown fuse, and he saved me the fat cost of a supposed compressor purchase. BUT PLEASE NOTE there are more fuses and one relay in the engine compartment to examine, see image of these below.

Symptoms - My compressor failed intermittently over a couple of days then stopped working entirely and the amber warning light/suspension fault message appeared on the dash. The truck maintained suspension for a few days more but eventually lost all air and settled on the frame stops. The in-cabin altitude adjustment switch was likewise inoperable. My ride became un-drivable with no ability to feed the suspension.

When first discovered, I examined the obvious fuses in the glove box and engine compartment as listed numerically in the owner's manual. I also got under it and pulled the shroud off of the compressor unit, pulling electrical connections, cleaning and reseating each, no luck.

Side Tip - Removing the shroud actually worked once before when I had totally mudded the truck when playing in deep water the third year of ownership. A month after that, the caked and dried mud inside the supposedly protective shroud was faulting connections and raising/dropping the suspension like a ghost in the machine. A few thorough air blasts solved all until this recent incident.

After discovering TY1's comment above I decided again to go through every fuse and relay in the glove box AND engine compartment once more. Not just looking at the listing of fuse descriptions in the owner's manual but also observing any icons in the diagrams that seemed to represent suspension. And I then found a blown 60amp fuse in the engine compartment next to the battery. Problem solved, (for now right?)

Total expense $4.19.

Here's a screenshot that highlights the engine compartment and glove box fuses and one relay to be examined.