hitachi EX 120-1 main pumps valve plate stuck in high travel mode

Hi everyone, I have a EX120-1 with a problem to do with the hi speed travel. I think the main pumps valve plate is not destroking by itself causing it to not travel in low speed. Im unsure what the pressures should be in the pilot hoses from the control valve to the top cover of the pumps. Has anyone else seen this issue where the valve plate is not going to maximum stroke ?

Thanks in advance for any help ,this has become quite a nightmare about lifting my track every which way i turn :Banghead

hitachi EX 120-1 main pumps valve plate stuck in high travel mode