Thread: AMK Compressor and "Normal Height Only" fault, and fix!

As promised, here is the story of getting my car off the bump stops without a compressor that worked at all.

I was stopped at a set of traffic lights when suddenly the car dropped to the bump stops with a new error code - "air inlet component failure" and a compressor that stopped sucking air completely on it's inlet pipe - so my trick of using my tyre compressor as a precharger to help the worn out AMK would no longer work.

I don't have photos of when it happened, so use your imagination a little.

First, make sure you select the correct line out of the compressor


It will finish like this on the resivoir valve block


It is a 6mm pipe, so I cut it with a pair of conduit cutters so it would be a nice clean square cut, and attached a high pressure joiner into position on the valve block end of the cut pipe.


Now, using some spare 6mm air line, and this blow gun nozzle (it screws into my inflation gun on the Max Air 3 - came as part of a very cheap Bunnings blow nozzle set)


I used a heat gun to soften the pipe enough to slide the hose a fair way up, so that it could hold the 150psi that my compressor cuts out at.

To put less stress on the compressor, the car was jacked up above standard height back and then front - if out in the bush, you can do 1 corner at a time if needed, using the OE jack.

Then using my IID Tool BT and the app on my phone, I had the car started, then went into Service/Test -> RLM Suspension -> Test Valves.

I then used this function to "Adjust Rear" until weight was taken off the jack, then jacked the front and did the same. The front needs higher pressure due to the extra weight, so my compressor was on it's pressure limit (150 psi), but the height according the my IID Tool live values is right on "Normal Height".

Afterwards, all I had to do was set the suspension to "Build Mode" (also removed the 20A fuse for good measure) and remove my 6mm pipe attached to my tyre compressor and attach it back onto the line out of the compressor.

So my new compressor arrived today - it is the one supplied by Britpart, but is a proper AMK unit. The mounting bracket is quite robust compared to the one on the D4 - so I think I will change the bracket to the new one when I do the swap.
In regards to duty cycle - this new unit has a 400 second (6 minutes 40 seconds) maximum run time - twice that of the top spec (200 seconds) AMK list on their website, which means that the D4 should not ever exceed this time limit.

I ordered it from the UK as the same part in Australia from a local Britpart reseller was quoted at $1155 inc GST + postage, and this one came in under $750 delivered, and took 6 days.

So, if anyone orders the same compressor I did, I found that the mounting holes are not tapped - so you will need to tap an M6 x 1.0 thread in the 3 points that are used before you can attach it to the mounting bracket.

All going well, I will have the new silencer and compressor installed Saturday morning so I can move onto the LCA bushes next.

Originally Posted by Grentarc

All going well, I will have the new silencer and compressor installed Saturday morning so I can move onto the LCA bushes next.

Justin, have you seen the other thread mentioning to "slot the top mount of the three mounts to aid installation" ?
I'm guessing this is related to the three points you've had to tap but perhaps is referring to the "L" bracket that mounts to the chassis.
Not clear to me so any photos etc appreciated (which will probably be painful when you're in the middle of the job!)

Also, for the bushes have you got a press like Tombies?

Cheers,
Scott

Originally Posted by LRD414

Justin, have you seen the other thread mentioning to "slot the top mount of the three mounts to aid installation" ?
I'm guessing this is related to the three points you've had to tap but perhaps is referring to the "L" bracket that mounts to the chassis.
Not clear to me so any photos etc appreciated (which will probably be painful when you're in the middle of the job!)

Also, for the bushes have you got a press like Tombies?

Cheers,
Scott

The slotting of the top hole is a Hitachi thing I think, as I can remove and replace my AMK compressor in under 10 minutes (less than 5 minutes each way). With the AMK, if you just undo the 3 compressor spring mounts/bolts and leave the mounting bracket attached to the chassis, the compressor will slide out towards the rear wheel quite easily.

The points I had to tap are the threads on the actual compressor so that the 3 T30 bolts have a thread to screw into

I will take some photos tonight of my new compressor on the bracket that came with it so you can get an idea of what's what without all the dirt and hard to see angles.

For my LCA bushes I will be ordering a generic press set that people in the UK have had great success with, and at about $150 or so, I will give it a go.

These are the 3 chassis bolt holes, as you can see, in not easy to reach places, especially the top one.



Here are the ones I remove ( T30 torx)

So the compressor and silencer have been replaced - the silencer is a little tricky to fit, but can be done.
This is why mine needed doing - I had hooked up my tyre compressor to where the EAS inlet filter is, completely forgetting the silencer is between the filter and compressor. My compressor has a 150psi cutout, so hooked it up, turned it on and let it hit its cutout. About 10 seconds later I hear a massive explosion under the car and plastic shrapnel went everywhere.


Here are the old and new compressors side by side


And here is the scoring on the bore of the old compressor

Does anyone know where the air filter for the suspension compressor is fitted if air con for the third row is fitted - On our D4 MY2011 the LH rear space is mostly filled with air con components and we cant see the air filter in this area - thanks for any pointers on where to look cheers

Originally Posted by Grentarc

The dryer is after the compressor, so there is no need to change it's design (yet?)

This is the filter that is in the cavity behind the LH plastic cover in the rear. The filter is clipped into the body at about tail light height.


If you open it up (the outside "cap" just pulls off) , the first layer is sponge - you can see with mine that the sponge doesn't fully seal up against the inside walls


The next (and final) layer is a thich felt pad - it too isn't a tight fit - not loose, but this is air we are talking about, so it will go down the sides, and carry a fair bit of dirt with it


In the bottom, you can see the ribs that are in place to give an even flow and to stop the felt from blocking the hole


After a bit of thought and discussion my father (Graeme) and I had the thought to change it to a paper filter, and just make sure it is changed like an engine air filter.



Edit - I got a response from AMK today that they have passed on my request to their Automotive Department, and if they do not get in touch, send another email to HQ