Stripped torx head screw in AMK compressor head

[BushDisco]

Hi all,
I recently committed to replacing all 4 air struts plus compressor on my 10 year old D4 (220k). Was getting floaty plus corrugations we causing it to walk so it was clear the dampers were stuffed even if the bags were still fine.

So anyhoo, new struts and new AMK compressor (updated model to the AMK in my disco prior to change, air intake in different location requiring me to drummel the plastic case). Much tighter suspension now and faster to rise.

Now that was done and a few weeks had gone by to make sure no issues I decided to service the original compressor. It’s not a hard job by the look of it, however 1 of the 3 small torx head screws in the cylinder head probably had more thread seal than the other 2 and even though I was very careful and undid all screws evenly I managed to strip the head :( (the other 2 came out clean).

Anyone know how to split the compressor so I can remove the cylinder head?

[BushDisco]

Stripped this far quite easily but can't seem to get any further. https://uploads.tapatalk-cdn.com/20210822/43c7001e0db02d26a2b0e87309dfdccd.jpg

[BradC]

Is that one screw beheaded and two minced?

[BushDisco]

No. I've screw without head. Two screws on and can be removed and reinstalled.

[BradC]

I can think of a number of ways of attacking/removing the headless stump, but I'd have thought without the head it would be more like a dowel and shouldn't be much of an issue.

Does anything loosen up and wiggle about when you pull the other 2 bolts out? Since I've never stripped an AMK compressor I'm out of further practical advice and well into speculation.

[BradC]

DISCO3.CO.UK - View topic - Amk Compressor rebuild attempt (https://www.disco3.co.uk/forum/amk-compressor-rebuild-attempt-178827.html)

You might be SOL at this point.

[BushDisco]

Thx Brad, so when I remove the two good screws the cylinder head comes loose but can't be removed (or maybe it can buy I'm not game to force it too much).

With the screws out the cylinder head is loose when shaken but still captive, not sure what is holding it in.

If I can remove it then I should be able to remove the headless screw using mole grips.

[BushDisco]

DISCO3.CO.UK - View topic - Amk Compressor rebuild attempt (https://www.disco3.co.uk/forum/amk-compressor-rebuild-attempt-178827.html)

You might be SOL at this point.Yep, stripped the motor down but that's a far add I've got.
It was built so it should be able to be unbuilt and rebuilt.

[DiscoDB]

Check this out:

https://ukarauto.com/guide/amk_compressor.pdf

[BradC]

Right, so the stuff I've found says you need to press the motor shaft out of the bearing. The screws you've removed drop the bottom of the piston off. The bit you can see is the top of the piston and it's attached to the rod.


Is there an AMK rebuild kit? - Land Rover Forums - Land Rover Enthusiast Forum (https://landroverforums.com/forum/general-tech-help-8/there-amk-rebuild-kit-85886/)

Check the images :
FOR MERCEDES W164 W221 W251 W166 AIR SUSPENSION COMPRESSOR CYLINDER PISTON ROD | eBay (https://www.ebay.co.uk/itm/392896929129)

[BradC]

Check this out:

https://ukarauto.com/guide/amk_compressor.pdf

And there ya go. The right information. Pressing that shaft out without being able to get in and support it from the rear looks like a "challenge".

[BushDisco]

Excellent, thank you both, much appreciated.

I'll have a good look tomorrow evening after work. I'll take my time, it's the replaced unit so spare now, plus not driving in lock down!

If successful I'll post a strip down and rebuild post.