Hi, I've read the previous post reg the "C1A20-64 (2E) Pressure increases too slow when filling reservoir" fault, which my 07 TDV8 L322 has started throwing 3-5 minutes after startup. But I'm not sure these symptoms are equal to the ones described here earlier.

I've recorded live values with the IID tool - see picture below.


The Gallery pressure start building up from 79psi to the max 182 psi. While gradually building up pressure the next 4-5 minutes, the compressor temp rises from 50 deg to 120+ deg C. Then this happens: 1) The reservoir valve closes, 2) Then the Exhaust valve opens and the Gallery pressure drop from 182 psi to zero. And the "C1A20-64 (2E) Pressure increases too slow..." warning comes up. After that the gallery pressure builds up again to appr 32 psi and stays there constantly. This has no effect on the lift level of the car - seems to stay at the same level as when started.

The car doesn't lower when standing still overnight, indicating that there shouldn't be any leakages in any of the air struts. The AMK compressor is not very old - I replaced the Hitachi compressor with the AMK one 4 years ago. When lifting the car from cold, it lifts fine - but maybe takes a bit longer than before. I've flashed the RLM-Suspension ECU twice; first time after replacing the compressor, then this weekend as well (just to be sure to have the latest firmware).

I'm not sure how the air pressure systems work with the valves and reservoir, but do you think that this behavior is caused by:
1) Worn out piston seal in the air dryer in the AMK compressor?
2) Leakage in one of the valves - or pipes to the valves?
3) Leakage from the reservoir tank?

I've bought the replacement kit https://www.ebay.co.uk/itm/114313842208 from airsealsuk, did the replacements, but still same issue...

I think now that it might be the piston in the AMK compressor that is worn out. Only 4 years since I bought and installed this AMK, but I cannot find any leaks.

Do any of you have any experience with this air compressor from aerosus: https://aerosus.net/land-rover/range-rover...essor.html Any good? Compatible with the AMK or the Hitachi compressor?

I have exactly the same problem. Replaced the compressor (twice) and also the rear valve block.
When neither of these made any difference, I finally think I’ve tracked it down to a leak in the reservoir. Lots of soapy water sprayed onto it resulted in huge bubbles when the compressor was trying to fill it.
I’ve ordered a new one, so hopefully I can conform this was the problem all along. Got - 2017 SDV8 Autobiography in Loire Blue
Had- 2008 TDV8 Vogue SE in Java black
Had - 2007 S/C in Stornoway Grey

Also check the airline feed from the compressor to the reservoir, they can chaff and rub through causing a leak, will give the symptoms you describe

Thanks Dave and Alan, I just installed the new Airsus compressor, and now it rises again. But still slowly (got the warning message "rasining slowly" ). It could be that the air pipe joint from the air suspension valve control unit to the compressor is leaking, will try with soapy spray tomorrow.

The car is holding the height while standing still - does that mean that the air pipes, the xover valves or reservoir are NOT leaking, or could there be a leakage there still?

There could still be a leak if its raising slowly, but let it settle now and get the reservoir fully charged, once it has you should not get the warning if raising form say access to normal height or normal to off road, if it continues you will need lots of soapy spray and keen hearing to locate a leak. Best of luck.