Hi hopefully someone can point me in the right direction...

I was filling my Ultra today and i got it up to 230 bar, shut the main valve off opened the bleed valve on the bottle and it just emptied the gun of air. I tried with the gun cocked and un-cocked but it still leaked out. i tried removing the fill probe after most of the air was gone and the remaining air leaked out of the fill valve. does anyone have any experience of this happening and if so was it an easyish fix or did you have to send it for repair? the gun is second hand so out of warranty.

thanks