Ragsf15e Posted January 16 Report Posted January 16 Anyone else have trouble with SA oil leaks? My SA was OH 50 hours ago, but there’s been a drip or two hanging off the bottom of it and a small puddle on the firewall “shelf” in the middle of the firewall just below the SA. I was hoping it was one of the gaskets going to the old (closed off) vacuum pads, but there’s all kinds of horror stories on Beachtalk. I think it could also be the shaft that drives the alternator pulley or the turbo’s scavenge pump which also come off the SA. Any stories of troubleshooting similar problems are welcome!
Fix Posted January 16 Report Posted January 16 I also had this problem with oil collecting back at the firewall in the "shelf" and even oil found at the front lamp house. Also thought that the leak came from T-Drive, Turbo etc. In my case it was a lose clamp at the Oil Stick Rubber Hose. It was the lower Clamp that was loose and oil got out downwards. Since the Rubber hose is covered with a metal sheet at oil cooler it took long time before I found it. Changed hose and 2x new clamps and secured the clamps. 1
kortopates Posted January 16 Report Posted January 16 Anyone else have trouble with SA oil leaks? My SA was OH 50 hours ago, but there’s been a drip or two hanging off the bottom of it and a small puddle on the firewall “shelf” in the middle of the firewall just below the SA. I was hoping it was one of the gaskets going to the old (closed off) vacuum pads, but there’s all kinds of horror stories on Beachtalk. I think it could also be the shaft that drives the alternator pulley or the turbo’s scavenge pump which also come off the SA. Any stories of troubleshooting similar problems are welcome!Is it dripping at the bottom below the pulley for the 2nd Alternator?If so, very common after an overhaul. The seal on that plate is very hard to seal. It’s a threaded seal. The good news is an expert TCM guy can can reseal it without removing the stater adapter. Still a number of hours to do it. Sent from my iPhone using Tapatalk
Ragsf15e Posted January 16 Author Report Posted January 16 7 minutes ago, kortopates said: Is it dripping at the bottom below the pulley for the 2nd Alternator? If so, very common after an overhaul. The seal on that plate is very hard to seal. It’s a threaded seal. The good news is an expert TCM guy can can reseal it without removing the stater adapter. Still a number of hours to do it. Sent from my iPhone using Tapatalk Its definitely in that area. As you know, it's hard to see. In fact, I just bought myself a borescope to get a better look. My mechanic has one, but I'd like to have a look and get some ideas before I talk to him. When I reach under and feel for the drip, it seemed to be either under the pulley area or possibly under the copilot side vacuum pad. I will know more when I see the actual area with my new camera! It's super frustrating because the SA is just overhauled, the rest of the engine is dry and looking great at 280 hours smoh. Now, hopefully we have an "expert TCM guy" around here... Thanks for your comments.
kortopates Posted January 16 Report Posted January 16 Just putting your finger at the bottom of the seal should be adequate to verify. Sent from my iPhone using Tapatalk 1
Ragsf15e Posted January 16 Author Report Posted January 16 45 minutes ago, kortopates said: Just putting your finger at the bottom of the seal should be adequate to verify. Sent from my iPhone using Tapatalk Any chance you could point me to the seal you were talking about so I can orient my search? The one I see on the diagram is #44 (blue highlight), but it doesn't indicate that it's threaded. It does seem to be the one closest to the pulley though. Thanks, Drew
Fix Posted January 16 Report Posted January 16 (edited) I had oil there to, under the T-Drive #23 and #42. Soon as I change the Oil Stick Hose it was dry at #23 and #42 + around all those parts. I had to clean that area several times and at last I found that I had that small leak at the Oil Stick Tube. It's located forward of the T-Drive on right side. Use borescope to check at Oil Stick Tube, it fits to see under. Or if you remove bottom cowling. It was not enough to the ground run to get the leak and oil mess. Had to fly 30min... Edited January 17 by Fix 1 1
kortopates Posted January 17 Report Posted January 17 Yep at the thread seal for 42. Sent from my iPhone using Tapatalk 1
exM20K Posted January 17 Report Posted January 17 On 1/16/2026 at 9:44 AM, Ragsf15e said: Anyone else have trouble with SA oil leaks? My SA was OH 50 hours ago, but there’s been a drip or two hanging off the bottom of it and a small puddle on the firewall “shelf” in the middle of the firewall just below the SA. I was hoping it was one of the gaskets going to the old (closed off) vacuum pads, but there’s all kinds of horror stories on Beachtalk. I think it could also be the shaft that drives the alternator pulley or the turbo’s scavenge pump which also come off the SA. Any stories of troubleshooting similar problems are welcome! Mine started leaking from the accessory drive seal at the rear at ~800 hrs. Over the next 6 months /100 hours, it got progressively worse. Since a failure here can empty the engine of oil, I elected to replace the drive. If it is only 50 hrs old, the o/h shop should address this for you. -dan
Ragsf15e Posted January 17 Author Report Posted January 17 3 hours ago, exM20K said: Mine started leaking from the accessory drive seal at the rear at ~800 hrs. Over the next 6 months /100 hours, it got progressively worse. Since a failure here can empty the engine of oil, I elected to replace the drive. If it is only 50 hrs old, the o/h shop should address this for you. -dan Ive got to do a little more investigation and see if i can be certain where it’s coming from. If it’s the threaded seal @kortopates mentioned, it can apparently be fixed without removing the starter adapter which is a big deal. The actual seal is only like $25 too. I will just have to find someone who has experience doing that as it involves taking off the back of the starter adapter where it connects to the alternator pulley. Next week I’ll play around with my new borescope and see if I can find exactly where it’s coming from.
kortopates Posted January 17 Report Posted January 17 Ive got to do a little more investigation and see if i can be certain where it’s coming from. If it’s the threaded seal [mention=7862]kortopates[/mention] mentioned, it can apparently be fixed without removing the starter adapter which is a big deal. The actual seal is only like $25 too. I will just have to find someone who has experience doing that as it involves taking off the back of the starter adapter where it connects to the alternator pulley. Next week I’ll play around with my new borescope and see if I can find exactly where it’s coming from.There isn’t really a gasket, just thread and sealant. The TCM sealant isn’t the best either. Many use an aftermarket sealant. Sent from my iPhone using Tapatalk 1
Ragsf15e Posted January 20 Author Report Posted January 20 On 1/17/2026 at 3:45 PM, kortopates said: There isn’t really a gasket, just thread and sealant. The TCM sealant isn’t the best either. Many use an aftermarket sealant. Sent from my iPhone using Tapatalk I flew it this weekend and got some pictures. There doesn't seem to be any oil on the shaft that drives the alternator. There is oil below the (closed off) vacuum drive pad - that has a gasket between the SA and cover plate. There also seems to be a drip below the seam where part 42 (diagram above) seals to the SA. It doesn't look like that joint has a gasket (from the diagram above). Is this where you mentioned the silk thread and sealant? Any recommendations for someone who is really good at this in the Northwest? Thanks, Drew
kortopates Posted January 21 Report Posted January 21 21 hours ago, Ragsf15e said: I flew it this weekend and got some pictures. There doesn't seem to be any oil on the shaft that drives the alternator. There is oil below the (closed off) vacuum drive pad - that has a gasket between the SA and cover plate. There also seems to be a drip below the seam where part 42 (diagram above) seals to the SA. It doesn't look like that joint has a gasket (from the diagram above). Is this where you mentioned the silk thread and sealant? Any recommendations for someone who is really good at this in the Northwest? Thanks, Drew Part #42, alternator drive in your pict, is where only thread and sealant are used. But if it only leaking from the vacuum pad cover, that's a much easier repair to just replace that gasket and re-torque the nuts - hopefully that's all it needs. Can't recommend anyone on the east side, but on the west side Command Aviation at Burlington, the DOM there Craig Scamehorn is a real engine guru if the part 42 turns out be leaking. But since he runs the shop these days I don't know if he's actually turning wrenches anymore - you'd have to call him. Not to say he couldn't supervise one his tech's to do it as well,
Ragsf15e Posted January 21 Author Report Posted January 21 1 minute ago, kortopates said: Part #42, alternator drive in your pict, is where only thread and sealant are used. But if it only leaking from the vacuum pad cover, that's a much easier repair to just replace that gasket and re-torque the nuts - hopefully that's all it needs. Can't recommend anyone on the east side, but on the west side Command Aviation at Burlington, the DOM there Craig Scamehorn is a real engine guru if the part 42 turns out be leaking. But since he runs the shop these days I don't know if he's actually turning wrenches anymore - you'd have to call him. Not to say he couldn't supervise one his tech's to do it as well, Thanks very much. I think I’ll try the gasket on the vacuum pad first with my mechanic and then go from there. Funny you recommended Craig! I know him well. Just saw him two weeks ago as we have our corporate plane maintained at his shop. If it’s still leaking at the thread seal I’ll talk to him. Drew 1
kortopates Posted January 21 Report Posted January 21 Craig is a great guy, before he was at Command Aviation he used to be the DOM at at a MSC on the east side that closed years ago. He knows more about Mooney’s than he’ll admit! lolSent from my iPhone using Tapatalk 1
Ragsf15e Posted January 21 Author Report Posted January 21 6 minutes ago, kortopates said: Craig is a great guy, before he was at Command Aviation he used to be the DOM at at a MSC on the east side that closed years ago. He knows more about Mooney’s than he’ll admit! lol Sent from my iPhone using Tapatalk Yes, I’ve seen quite a few Mooneys in his shop. There’s an Encore in there right now actually.
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