Background:
My 2010 LR4 HSE (5.0) was originally fitted with the Hitachi air compressor for the suspension. This unit actually worked really well until 2018 when it started huffing and puffing. I didn’t have an opportunity to service it so it essentially died in early 2019 (it probably could have been saved if I would have replaced the air dryer).
I didn’t have time to do the replacement myself and wanted to get the truck back on the road as soon as possible so I took it into the nearest dealer. They were really nice and recommended replacing the Hitachi with the newer AMK. I agreed, they had the compressor on hand, did the installation and updated the firmware (the software requires the newer software for the Air Suspension ECU). We were back in business in ~ 48 hours.
Fast forward to 2024, and I decided to replace the AMK the dealer installed with a new AMK unit as part of my massive refurbishment / services project. The rationale was to do a complete upgrade and then take the old compressor and parts and refurbish everything so I would have a spare either in case I blow up another compressor or to swap out and then do another refurbish in ~ 5 years.
I purchased the full kit from Atlantic British which works great (see Air Suspension EAS Compressor LR072537 Or LR023964, Original Equipment By AMK, Upgrade For Older Vehicles plus the EAS Compressor Bracket LR044034 For AMK Style Compressors, On Land Rover LR3, LR4, And Range Rover Sport). The old compressor was a little more beat-up looking than I expected including corrosion on all the fittings as well as some corrosion on the aluminum housing but there were no issues getting it out and installing the new kit. The new pipe fittings, springs/boots, bolt assembly / fittings, wiring and everything worked perfectly so I thought that was superb.
And new compressor worked great, no issues.
But then we started to tear down the old (AMK) compressor. The internals of the compressor such as the wiring and the piston/cylinder are all in good condition. The air dryer, however, was not and did need replacement so these compressor services are definitely warranted.
Unfortunately, the shop that is working on the compressor broke the piston when pulling it out (it is either a brittle alloy or aluminum) and the rebuild kit I bought from 4X4 Air Seals in the UK does not include new or replacement piston rings (so funny enough, the 4X4 Air Seals does not recommend a full rebuild (!) but provides materials to replace & refresh the dryer unit as well as the associated O-rings).
These AMK units are used on a variety of other air suspension systems for European cars including Mercedes and BMW (so they are not a unique Land Rover part).