Get it on diagnostics and watch the live data on the height sensors and look for twitching. Are there any changes in height that makes the pump cut off. Removing the silencer from the block will give you a good indication of what is happening mate .Fitted a Recon Pump from Mercia Air limited..
A proper recon OEM pump and she rises and lowers as she should...
A good and proper hoon through wales was needed, scared myself a few times on the straights the 2 ton brick can move when you want it to..
Only "slight" issue i have is No leaks, however the pump is running a bit too much for my liking, it sits at around 68c after a good drive...
Maybe i'm paranoid..
Thats prolly what the "P" stands for?
Paranoia38A