What could be the reasons for both the engine driven and auxiliary vacuum sources to fail? I flew first leg of the flight everything was fine then I got back in the plane and did runup and no vacuum. Any help would be greatly appreciated.
What could be the reasons for both the engine driven and auxiliary vacuum sources to fail? I flew first leg of the flight everything was fine then I got back in the plane and did runup and no vacuum. Any help would be greatly appreciated.
I would inspect all the vacuum hoses , you may have a broken hose or one may have come loose. If that shows no problems I would remove and plug the hose from the engine driven vacuum pump and then try the backup system. If still no vacuum reinstall hose to the engine driven pump and block the line from the backup unit and try again. If all is ok then you have a failed pump that is allowing air to flow back through it. Good luck.
Have you read section 10 of the service manual?