The 06 is all of a sudden dropping quite a bit over night. Over a couple days it on the bump stops, front and back. I removed F26 yesterday evening and sure enough, it had dropped substantially by this morning. Unfortunately, I forgot to measure but I believe its dropping evenly on all four corners. Maybe a little more in the front but I'll measure that tonight.

From reading this forum, the diagnosis seems to be failure of the center valve block. Agreed? If so, I'll get a new one coming and start researching on how to replace myself.

Tks!

 

The center valve block would not be the issue at all. All that one does is regulate the reservoir supply and house the gallery pressure sensor. It in no way regulates air front to back, etc. With the fuse pulled and all corners dropping you have leaks front and back. In theory if the front and rear valve blocks are fine you could disconnect the supply line to both and it still would not drop at all because east strut is "sealed" off from letting air in or out. But if there is contamination or failure of the valve blocks, then they can simulate a leak and dump air back into the gallery and out the compressor. You could also just as easily have a leak in t strut. So sometimes one way to check is to set it to off-road and see if it drops (still pull fuse 26). If it does not drop in off-road but does in standard height, then there is a good chance the strut has a crack in the air bladder and is leaking externally. Also keep in mind if one strut leaks the other had to take up the weight, so it will drop too of course.

Basically you need to diagnose the issue properly before tossing parts on it. If you are handy you can rebuild the valve blocks for about $30 in o-rings from eBay (they make kits). It is a cheap way to see if it will fix the issue. Just keep in mind, usually they "fail" due to desiccant contamination from the compressor dryer. This is due to lack of maintenance and age. The desiccant that drys the air breaks down and can send a fine powder down the lines into the blocks. So the proper thing to do is replace the desiccant, if possible, then wait a week or so before rebuilding the blocks. Gives time for the powder to work through. If you dont take care of the desiccant, your valve blocks will be back in the same state in a few weeks or months.

 

The hard part about diagnosing our EAS is that at first glance, the visual symptoms all look very similar . .
I've had: leak at front strut connector, crack in dryer cap, leak at air tank connector, powder in front valve block . . all resulted in similar lowering overnight

Do the known first: soap/spray all connections, rebuild compressor, replace desiccant, rebuild valve block(s)
Cheap, and diy friendly - just be methodical . . once you discover the issue, it should be pretty obvious

 

Tks for saving me on a bad decision guys. I replaced the compressor with a new one a couple years ago so may be left over desiccant from the old compressor. I will order a rebuild kit for the valve blocks and start there since they probably need rebuilt anyway due to changing out the old compressor.

I will do the work myself but I am somewhat intimidated by the location of the rear block. Any advice on how to get out and then back in? It’s in a tight spot.

tks

 

I left the rear block in place. It comes apart and the part without the valves stays connected. Still had to remove it from its mount and deal the airlines, but much easier than a full removal. Safe that for when a rebuild does not work (as i an weak solenoid).

Hope that helped.

Jeff

 

Thanks for the help!

I pulled the fuse and left the truck with raised off road suspension setting and discover the drop is almost 100% in the front. Both wheels with equal drop. I’m thinking this points toward the front valve block. I’ll get a rebuild kit ordered and hopefully rebuild the valve block on Saturday.

As far as rebuild kits are concerned, is there a specific kit I should target or are they all basically the same from a quality point of view?

 

I originally had success with just cleaning/light silicone spray on re-used o-rings
if originals seem undamaged - getting rid of the powder may be enough

I did buy a set off ebay which seemed to fit fine for a following rebuild (only used front set so far)
https://www.ebay.com/itm/226412552563

 

Hi all,

As far as cleaning the valve block itself, I’m guessing swabs and alcohol will do the trick. But for the rubber gaskets, what do you recommend coating them with? Grease, silicone, other?

 

Hi all,

As far as cleaning the valve block itself, I’m guessing swabs and alcohol will do the trick. But for the rubber gaskets, what do you recommend coating them with? Grease, silicone, other?

 

Use isopropyl alcohol since we do not know the exact type of rubber o-rings and some other alcohols can cause rubber to swell. I would not coat them with anything tho, it could cause any last little bits of stuff in the system to stick to em. I think just a good cleaning will do the trick.