Thread: Old D3 air suspension

I still have the hitachi, I have a 2008 and did rebuild it about 5 yrs ago. I have also just replaced the disicant and the usual symptom of this needing to be done is the car won’t “ fart and self level “ when you turn it off and let it settle.

If I was in your situation which I have been , I would start by as soon as you park the car for the night , open the bonnet and pull the 20a suspension fuse which from memory is 3rd from bottom but the picture is under the lid of what is what. This will stop the car self levelling during the night and you will see if the leak is front or rear as the car will sit down at the end leaking.

Then you can start finding leaks with soapy water in a squirt bottle or similar. Mine had lots of very small leaks in the rubber fold of the air bag which I put down to age. I also done the Orings in the front valve block as it was a very easy job and plenty of videos on you tube.

Once you have determined where and what is leaking you can make your choice from there

At the age of yours , and seeing as you have ordered them, I would replace the struts, check and replace the disicant in the hitachi, it’s not a hard job and if you desire do the valve blocks s well.. I think you will be surprised by how different the ride is with new struts especially if you do any rough or off-road stuff.

Cheers Bulletman

The AMK is not a better compressor it is just a different compressor. With rebuilds the Hitachi will go on and on. My car is a 2007 with all original suspension components except for the compressor which I rebuilt. I had a air leak but it was internal back through the compressor and out through the exhaust valve which did have a bit of crud in it sop was cracked open allowing the air out.

So why have you bought all that kit without checking first what the issue is - my car is 14years old and 200,000km and all works at the moment and like when the compressor played up - I diagnosed the issue and sorted it - the specific air leak at the exhaust valve was fixed with a whack with a rubber mallet to dislodge the obstruction.

As you have got this extra stuff well put it in so you know where you stand and just rebuild your Hitachi.

Originally Posted by Bulletman

If I was in your situation which I have been , I would start by as soon as you park the car for the night , open the bonnet and pull the 20a suspension fuse which from memory is 3rd from bottom but the picture is under the lid of what is what. This will stop the car self levelling during the night and you will see if the leak is front or rear as the car will sit down at the end leaking.

Then you can start finding leaks with soapy water in a squirt bottle or similar. Mine had lots of very small leaks in the rubber fold of the air bag which I put down to age.
Cheers Bulletman

I've done this actually. Forgot to mention it. The rear dropped 45mm or so, the front dropped 15mm. I had a go with soapy spray but I don't think I achieved much. Maybe it wasn't soapy enough. Maybe it'd be easier with the wheels removed. I had a spray on the front valve block but didn't see anything.

Originally Posted by 101RRS

So why have you bought all that kit without checking first what the issue is - my car is 14years old and 200,000km and all works at the moment and like when the compressor played up - I diagnosed the issue and sorted it - the specific air leak at the exhaust valve was fixed with a whack with a rubber mallet to dislodge the obstruction.

As you have got this extra stuff well put it in so you know where you stand and just rebuild your Hitachi.

Because the dampeners are shot. They're original and you can feel the car wobble and pitch on braking. I got the compressor/valving rebuild stuff after reading up on all of this stuff and deduced that it was probably something to do with the compressor, specifically the desiccant, and having the rebuild kit was probably worthwhile regardless.

It's good to hear your results with rebuilt Hitachis. I feel more confident about that now.

I think you are on the correct track to do all 4 struts complete, the Hitachi rebuild kit should see your compressor last without any issues as long as you remember that you should replace the cap. Its is renown for cracking between the 2 air lines, you can now get an alloy cap that stops this happening.

Took me several goes to find the air leaks in my front strut as the rubber had perished and it had about 20 micro leaks.very soapy water and a small paint brush to hold the soapy liquid to the surface.

You can filter then heat the old dissicant if need be which is what I do as I like to have some spare stuff handy as the humid tropical weather in Darwin sees it need to be done on a regular basis.

Cheers Bulletman

Originally Posted by Bulletman

I think you are on the correct track to do all 4 struts complete, the Hitachi rebuild kit should see your compressor last without any issues as long as you remember that you should replace the cap. Its is renown for cracking between the 2 air lines, you can now get an alloy cap that stops this happening.

Took me several goes to find the air leaks in my front strut as the rubber had perished and it had about 20 micro leaks.very soapy water and a small paint brush to hold the soapy liquid to the surface.

You can filter then heat the old dissicant if need be which is what I do as I like to have some spare stuff handy as the humid tropical weather in Darwin sees it need to be done on a regular basis.

Cheers Bulletman

And check for leaks at raised or extended height as it unfolds the rubber air bag where the folds can conceal or hide a leak at normal height.

Yes the rebuild kit has an alloy cap. And yes I searched for leaks with the suspension extended, but I found nothing obvious.

I think I'm on the right track too. I just need to work out whether to rebuild the whole compressor or just replace the desiccant, and whether to rebuild some of the valve blocks