Mustang 310 weak on left drive

[Bryan in Iowa]

My 310 is slow or weak on one side . Been like this for over 10 years. Pumps had been rebuilt at one time . Not sure if it was after that I noticed it or not . I checked drive motors in past and have replaced broken orings in them . It dose not make noise or get worse when hot or cold, just constantly little bit weaker than right side . So,,I have not checked pressure on test fittings on either pump yet . If one is lower , is there an adjustment on pump?

 

[Tazza]

Check that there is no wear in the steering likages. If there is too much wear, the steering linkages can bottom out where the steering levers come out. If they are free, the pump or a drive motor could be worn.
Just how much slower is it going? if it's just a little, i wouldn't be worried. I had a 743 that did this slightly, you would need to correct a few times doing long straight runs.