I was told by a mechanic that the air compressor in a lorry produces it’s maximum pressure when the engine is revved to 1100rpm and that revving it any higher won’t make the slightest bit of difference. Can anyone shed some light on this?
Not sure about a compressor but I was told with a tipper, 1400rpm is the max, anything above wastes fuel.
I’d like to know too.
compressors and tipper pumps can only pump as fast as the air or oil can refill the cylinder from the storage tank any faster and a stall is caused like putting your hand in front of a fan on the out flow the fan runs faster but does not move air.
Just let it tick over of a morning while you do your checks this should build the air before you finish
Dafs are at there best at 1200 rpm any more is pointless and wastefull. our lot have tested them from empty to full air @ just under 2mins . and the pto on our walking floors run at 1100 rpm no gain for higher revs
i had a symbol pop up on the dash of a fh only once,it was like a airtank with a clock on the top ,whats it for 
its only happened once for a few seconds,i forgot all about it untill now,owt to do with air pressure,it popped up when i was goin down the mway so there was plenty of air in the tanks 
If the Vehicle can lose 1 tenth per Hour,thats 1 Bar in 10 Hour. So you shall be OK to pull of without long Pumping. 
1200 it is, I’ll not thrape it anymore so when I’m hurried.
When the air is low on my Premium, it automatically increases the revs to about 900rpm. So I assume Renault sees this as the optimal engine speed to build up the air.