Hi - Im just wanting to throw this out as a means to figure out if my assumptions are correct. I thought, before going to all the trouble of replacing air components (vs. a coil over) I'd figure out what needs replacing.

I know I need a new pump - this is known. It's not keeping up and is throwing errors when triggered for prolonged use. Pulled the fuse last night and over night (or so) and after putting the suspension it in highest position the truck sank an average of 2 inches in the back and .5 to 1 inch in the front.

Assuming this is the front and rear valve assembly and not the airbags themselves. One corner did not drop lower the than the others.

Are there three valve blocks? Front - Rear - "Middle" (?) and I am assuming, most likely, the front and rear need replacing.

I'd like to keep the air if possible. But I don't want to repair to the cost of a coil over then get a coil over anyway.


Thoughts?

 

I'd say it's safe to say the rear valve block is failed....changing both would be a good approach if you don't really care which one it is. Sometimes the sleuth in us needs to have that answer. It could of course be both too. There is a valve block near the air tank (aka "gallery") I believe, as well. Someone else can clarify.

If it were me I'd change the compressor and both valve blocks and call it good I'd want to read the fault code though...maybe you don't need a new compressor but just need a serviceable part on the compressor...I just went through that and saved myself $1300 by replacing the air drier rather than the whole compressor.

I concur that you should try to save the EAS. It's a great suspension when maintained.

 

I will add some things to houm_wa's advice and expand on some thoughts.

First things first, probably need to replace that compressor. But I will add one big "BUT" to the equation. It's very possible you have a restriction in the dryer. What happens is these evil little desiccant beads sit in a black canister and absorb moisture brought into the compressor. Air is passed through, very hot air mind you, and the water is absorbed. When venting, some of that moisture is taken back out with the exhausting air but its cooler air so the effect is not efficient. Over time the constant hot moist air and moisture trapped in the beads starts a break down process. This can clog filters within the desiccant canister itself causing poor compressor performance. Since there is a bypass for exhaust, a restriction here would not necessarily make the truck drop slower when commanded. Anyway.. you could try to service the canister and you can operate without any desiccant in it. Just do not do it for long. If things run fine, then this may mean you don't need a new compressor just yet but you do need new desicant.

Now let's talk desicant. You can get it cheap on eBay, a nice jug for $25 or so. Will last a few changes and ideally you change it every couple years or so. But that break down I talked about? Well those filters are not 100% good at getting it all. Between road vibrations and stuff some of the particles can work under the filter and into the main gallery. The main galley is the entire "plumbing" system between the valve blocks. Once it gets in there it can easily make its way to the valve blocks and get stuck on the o-rings. When that happens, you appear to have a leak in the system - cause you do. But you can rebuild the valve blocks and install all new o-rings or even just clean them. I will addd that since valve blocks are solenoid driven they can also "burn out" over time. Typically that means they are weak to open and let air in/out though. Total failure usually means they stay closed, their default position.

So what to do? Well I really would at least look at the dryer assembly on the compressor, its black on the Hitachi compressor and easy to spot since its so large. I am not sure if the AMK compressor has a serviceable canister. But assuming Hitachi, remove and open it up. Be sure to properly disconnect the air lines. Read up if you are not familiar with hot they come off. Done right its easy. Clean the filters, looks for particles, etc. And Like I said, you can empty it and clean it out and run it with no desiccant to see how it behaves. Here is the thing though, assuming you find particles that means they are in the lines. So replacing valve blocks right away will solve nothing. I generally recommend servicing/replacing the compressor and operating it for a while to help purge out some of the particles over time. Only then service/replace the valve blocks. Otherwise those particle can end up on the new blocks and you end up with leaks again at some point. Ideally one would disconnect all the lines and purge with a fluid/air compressor wash out.

 

Thanks very much for the detailed reply. I do appreciate it.

Since I have no idea the condition of the compressor I am assuming it needs replacement. It is very loud and I am sure it is leaking where it shouldn't. The previous owner rebuilt it, so again, no idea if proper procedure was followed (speaking of which, I should probably look that up). Not to mention that they lost the cover, so the whole thing has been subject to road elements and god knows what for a while.

I had issues with the valve blocks before and although purchased a kit with O rings, found out it was just as easy to replace the whole thing (leaked air through the electrical connector!)

I do like your idea of running a new compressor and THEN replacing the valves no matter which way I go - that makes sense.

 

So LR direct has a Dunlop compressor. $100 more gets you a proper Hitachi. Rockauto has SKP and Hitachi.

Anyone worked with the Dunlop? Or should I just be all in with a new Hitachi brand?

 

Dunlop was an alternative OEM. It will function and look just like the Hitachi. They also made replacement air struts at one point, still might not sure. So no worries, should be fine.

 

Sweet thanks - that's all I needed to know!

 

Decided to take it out this morning just to see what I could do before replacing it.

I seems the Voss connectors were loose and the hose connecting one of the ends was some what crimped and therefore probably didn’t have ideal air flow.

I also emptied the desiccant. Over the floor.

Green and a bit discoloured. This is silica gel in bead form no? Can I just use any bead desiccant?

anyway, one connector had been replaced but the other had not. And this was loose. It’s the one on the left in the picture.

It doesn’t appear this threads in rather it sits flush and does the job. Can this be replaced easily with a more modern one?

 

also…is the air hose 10mm OD?

 

10 or 8mm i cant remember, desiccant beads are fine as that's what they use. Get it on Amazon for cheap.