Duane Baker Posted November 23, 2019 Report Posted November 23, 2019 Is the vacuum regulator hard to get at? I have low reading, top of the white, bottom of the green, the reading is the same even after the pump failed and replaced. Also what should the gauge read with the stand buy pump? Quote
CaptRJM Posted November 23, 2019 Report Posted November 23, 2019 Bottom of the green is OK. Are your vacuum instruments working properly? From what I’ve been told, from several sources, is that you don’t need to run excessive vacuum. The higher the vacuum, the more wear on the instruments. Quote
larrynimmo Posted November 23, 2019 Report Posted November 23, 2019 when I had diminishing vacuum....(back when I had a vacuum pump) issue ended up being cracked plastic hoses between instruments... I had it repaired and it worked perfectly....when I went glass to E5 & G5 I got rid of vacuum system. Quote
cbarry Posted November 23, 2019 Report Posted November 23, 2019 Check the rubber tubing running to the gauge. You may have some old hoses that are breaking down not allowing for accurate vacuum indications. Quote
PT20J Posted November 23, 2019 Report Posted November 23, 2019 Vacuum regulator is on cockpit side the firewall, on the pilot’s side. Make sure you check everything else before messing with the regulator. Biggest problems are filters that haven’t been changed and old deteriorating hoses - sometimes they delaminate and the inside collapses but they look OK from the outside. I get 4.75” with a new Tempest pump at sea level. About 4.5“ at 10,000’. A little rise if I turn the backup pump on. Skip 1 Quote
KB4 Posted November 24, 2019 Report Posted November 24, 2019 My J, POH calls for 4.25-5.5 as desired suction range. Quote
PT20J Posted November 24, 2019 Report Posted November 24, 2019 8 minutes ago, KB4 said: My J, POH calls for 4.25-5.5 as desired suction range. Service manual (37-12-05) says to set to 4.75 +/- 0.25. Quote
KB4 Posted November 24, 2019 Report Posted November 24, 2019 13 minutes ago, PT20J said: Service manual (37-12-05) says to set to 4.75 +/- 0.25. Thanks for updated info. I had G5 HSI installed so no more vacuum issues for me. Quote
Duane Baker Posted November 24, 2019 Author Report Posted November 24, 2019 Filter replaced 4/19, 85hr since. No numbers just white and green, vacuum instruments seem to work ok. Quote
carusoam Posted November 24, 2019 Report Posted November 24, 2019 Duane, In the green by the smallest amount, is still in the green... the instruments will work perfectly well... Continuing to operate this way would be sub-optimal... Finding an instrument shop to chase where the vacuum is and isn’t is probably a good idea... See how many fittings you can find, take a pic of, look for cracked lines, and things that are not right... Start with adding a Vac gauge that has numbers on it, temporarily at least... The life of the vac system... is getting closer to its natural end... It may often be wiser to spend money on the next digital solution... PP thoughts only, not a mechanic... Best regards, -a- Quote
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