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vash
07-28-2013, 06:56 PM
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.

vaflier
07-28-2013, 08:48 PM
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.

vash
07-29-2013, 06:00 PM
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.
Thank you, the pump was found to be bad, and we are investigating the aux. backup.

martymayes
07-29-2013, 08:42 PM
Thank you, the pump was found to be bad, and we are investigating the aux. backup.

What kind of backup system?

Kurt Flunkn
08-04-2013, 10:25 AM
Have you read section 10 of the service manual?

vash
08-04-2013, 04:06 PM
What kind of backup system?
Vacuum from the manifold is the aux. We think that some debris from the decintigrating pump shaft made its way into the check valve holding it open which is what caused us to lose vacuum from the aux source simultaneously. Thanks.