Skip the DG

[Cadstat]

I had to pull the Edo-Aire DG and send in for repairs. Can I connect the vacuum hoses bypassing the DG without doing any damage for other components and fly the plane?

[pierre smith]

As long as all hoses go somewhere and none are open-ended, sucking air. You should only have one hose from the AH now.....from the filter to the AH, then to the vacuum pump.

Best,

[Cadstat]

Originally Posted by pierre smith

As long as all hoses go somewhere and none are open-ended, sucking air. You should only have one hose from the AH now.....from the filter to the AH, then to the vacuum pump.

Best,

Pierre,
As always you are there to help and usually the first responder. I really appreiciate your 'know how' and willingness to share it. Thank you.

I have 3 hoses but two were 'tee'd' on the back of the DG. Are you saying the correct flow is usually -air filter- to -DG- to -AH- to vacuum pump? I couldn't see under the dash the night I pulled the DG but I bet the smaller extra line may go to the suction gauge in the panel. I'll track the hoses back this week end and I should check the air filter anyway. I had 5 annuals at the local FBO on the 210 and they never once checked the filter which looked like a door mat when I had it changed by someone else.

[pierre smith]

John, on our -6A, we went from the filter to either the DG or AH...can't recall, then on to the vacuum pump, minimizing hoses, connecting them in "series", if you will.

I don't quite understand why your DG had two Tees in the line but for now, you may either have to plug open ends or just use one line from the DG to the pump, until your AH comes back from the shop.

Best,

[ColoCardinal]

Something else you may want to consider is placing another filter between the vacuum pump and the instruments. When vacuum pumps fail, the vacuum in the lines ansd instruments sometimes sucks some of the bebris of the pumps failing vanes into the instruments. Shortly after replacing the pump, you would be replacing the instruments too!

[airtractor8]

Here is a schematic of a typical vacuum system to help you out from the master himself , Tony Bingelis "Sportplane Construction Techniques" handbook.




Good Luck
Graham

[Cadstat]

Thanks for the picture. I plumbed up the by pass and was concerned at first by not showing any suction on the gauge but likely the pump isn't working against anything. Works fine. Had the added benefit of finding a bad wiring connection on the mag switch while I was pulling the DG.