Air Compressor Rebuild ??

https://www.aulro.com/afvb/images/im...018/03/166.jpg

This is when I first opened the top of the dryer, some of the crushed dissicant

https://www.aulro.com/afvb/images/im...018/03/167.jpg

This is the stuff that came out from under the metal top filter , it looks in good condition but I am unsure if it has changed colour with moisture or not. the new stuff was a dark green colour

https://www.aulro.com/afvb/images/im...018/03/168.jpg

The filter pad directly above the compressor , so at the bottom of the dryer. not sure if its black from compressor exhaust or heat but the pads themselves were not to bad.
Car is a 01/08 D3 and to my knowledge the compressor has never been removed.

Cheers Ean

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Originally Posted by Ean Austral

So some thoughts on the rebuild. I attacked mine as I had the fault of the compressor taking to long to build pressure or something similar to that. I had already ordered the rebuild kit - albeit without a new dryer end cap - and the rebuild wasn't that difficult and I think in hindsight it wasn't really in need of a rebuild . With the install I had the fittings leaking in the dryer end cap which I managed to fix with some new pipe and a couple of joiners . Low and behold start it up and all good for about 3 or 4 minutes and I hear the compressor start up. I did some leak checks and sure enough there is a crack in the end cap and its leaking enough to have the pressure drop in a couple of minutes. In all honesty I think this may have been the initial problem , as I took great care removing the cap and altho not impossible it could have cracked on removal , I think it unlikely. Ordered a new end cap today , and covered the other in some epoxy to see if that will hold till the new one arrives , but if I could go back knowing what I know now I would check it for leaks/cracks before assuming it needed a rebuild. Just my 2c worth Cheers Ean

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Good job Ean , had the same (to slow to pump up etc ) about 12 months ago and on checking found a leak on the front valve block , ok after fixing that .
My compressor is now 10 yrs and is going well but was a bit concerned about the stuff in the dryer but looking at yours i might just leave it untill something says different , ( the old saying dont fix it if it aint broke ) Perth is a bit dryer than Dawin so the desicant or what ever you call it should be ok . Thanks for posting the Pics much appreciated . Al

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Originally Posted by Grappler

Been working through giving the EAS a birthday. Replaced front struts and levelling valve that had white desiccant dust contamination. Had a major fail today trying to refurb the Hitachi compressor. I broke the top of the piston attempting to prise the ring seal retainer off. My better judgement said the instructional video on the kit suppliers website looked dodgy but I went ahead anyway[bighmmm]. The vehicle will have to stay on the hoist till I work out a solution. I ordered a piston and cylinder kit from USA

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Piston and cylinder arrived in less than a week (quicker than from East coast Aus). Apart from needing to machine the wrist pin holes out to make an interference fit, the assembly was straight forward
I had already refurbed the air drier, which included the upgraded o ring carrier between the perforated metal plates and an upgraded drier cap. The improved o ring holder will reduce the powdered silica bypassing like in Eans pics.
After putting back under the vehicle, the air system recharged from empty in a few minutes and no bubbles.
Only time will tell if this has been an economical exercise.

Hi there Luke,

is is your compressor still available mate?

sent you a PM but your inbox is full apparently?

cheers

Mitch

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Originally Posted by Lukeis

I have a rebuilt hitachi compressor which never fixed itself, I’m pretty sure because the piston seal isn’t snug enough to keep the pressure so I ended up buying the AMK one instead

The compressor works (as in runs) and the dryer, decidessant and pads are all brand new, plus the dryer cap has the new alloy top on it instead of the plastic one so lots of usable parts

free to a good home if you want to pick it up - northern beaches Sydney

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I pulled my compressor out this week and checked the air dryer....

this is is what I found

Attachment 150400

Attachment 150401

Attachment 150402

The dryer was almost completely blocked so I’ve ordered a new one.

Mitch

I notice that no one`s mentioned whether the system needs to be de-pressured before compressor removal, but some where I read that it needs to be!! Is this true??

I've done mine both as a full rebuild and a couple of dissicant changes and never de-pressurised the system.

Bulletman

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Originally Posted by nigel1515

I notice that no one`s mentioned whether the system needs to be de-pressured before compressor removal, but some where I read that it needs to be!! Is this true??

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There's a non-return valve immediately downstream of the compressor assembly, so there's no need to de-pressurise the rest of the system if only the compressor assembly is being worked on.

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Originally Posted by nigel1515

I notice that no one`s mentioned whether the system needs to be de-pressured before compressor removal, but some where I read that it needs to be!! Is this true??

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By the time you pull the compressor out after you've disconnected the airlines there's no air pressure on the compressor side. The NRV keeps pressure in the circuit.

No issue to deflate all EAS bags and the circuit though, that's what I did, took the rebuilt compressor about a minute to refill, IMHO a good test of the system.

No need to repressurise the system - I drove around for approx 1000km with no compressor fitted at all - just need to be happy that the system will hold pressure, it does lose a little each time it height adjusts though.

However if you are going to change the desiccant you will probably need to depressurise to clean out the central valve block of desiccant dust.

Garry