CHECK FOR AIR LEAKS,SERVO PIPEWORK ON THESE AND RUBBER CONNECTING PIPES ARE COMMON FOR LEAKS,HAVE YOU TREID SPRAYING AROUND WITH BRAKE CLEANER, OR CAN YOU SMOKE TEST IT FOR LEAKS. I HAVE OLD SCANNER AND SOLUS, BUT FIND THEY ARE NOT VERY GOOD AT READAPTION,I USE BOSCH KTS ON THESE PROBLEMS, MY GARAGE IS IN OTLEY, HAPPY TO TRY THIS FOR YOU.