Opinions please gents. I have made my own conclusions but open to experience of others. The vehicle does rise and fall but takes a long time maybe 90 seconds before the pump stops. Code is Suspension slow to rise.
Gallery pressure reaches around 140 to 160psi when pressuring the reservoir and or extending the bags. Gallery pressure at idle is around 30psi. With the car at access height. All RH sensors read very similar figures. All sensor voltages are the same 4.8 to 4.9v. When normal or off road is selected, the pump starts, the valves are opened and usually the back goes up first, then the front, then back and then front. After the vehicle has reached max height, the pump continues to charge the reservoir at 135psi or so. When the operating pressure is reached (unknown as I only see a sensor voltage rise not a psi value) the pump switches off. Watching the gallery pressure and the RH sensor values, nothing changes, no drops etc. Vehicle remains at selected height indefinitely. Because of this I am under the impression the pump is allowing too much blow by and so cannot operate at the pressure intended. I do not know how long it should take for the system to reach full operating pressure, other than to say 90 seconds is not right! My client has parts insurance but I don't just change things for the sake of it, so want to fix it not fluke it. Opinions and experience welcome. Thanks

 

Does none have any experience with the LR4 AS system?

Did some more observational tests today. With the car on the floor, demanding Normal or Off Road results in the vehicle rising very slowly. The limits is reached and two minutes later the pump stops. No values change whilst at either of the three positions. If the vehicle is dropped to access with the reservoir full, and Normal or Off road height is demanded, the vehicle raises quickly. Maybe 8 - 10 seconds. If the pump is allowed to finished between each height demand, the operation is quick. From Access with the reservoir supply dumped (by diagnostics), rising to the off road position takes over 4 minutes. If the reservoir is full, rising from Access to Off road takes less than 15 seconds. This to me suggests a bad pump or poor air feed to the pump. (Atmospheric). Can anyone chime in with an opinion please? Id there a serviceable filter. Not had a chance to look at the car underneath yet. Thanks

 

I now have the full service manual so I know where I am going. Gallery pressure should 25bar or 360psi when inflating.

 

I haven’t worked on this system yet, but I’ve heard of problems with the exhaust valve - might be leaking. Not sure if its a serviceable part or not.

 

I stripped off the Dunlop unit from the LR4 today. With side rails on the chassis that was a laugh. Anyway I checked all the pipework I could see and its all fine. With the pump on the bench I dismantled the exhaust valve, and checked the o rings. Saw no issues there. I stripped off the dryer and that's where the issue is. Rust! In fact for a 6 year old vehicle with only 70k on the clock the amount of rust underneath was a disgrace. Above the pump acoustic housing the rust is beyond surface but not structural. Rust converter painted on the area after wire brushing. Anyway the desiccant is rust coloured and welded to the first filter. That filter is impenetrable! Sadly rusty water has gone into the piston cylinder. I could barely get air through the solid filter with my airline.