Mooney TLS Bravo Scavenge Pump

[affricate]

I make many cross-country flights, often from Arizona to Louisiana. I do know the POH states the Bravo requires 10 quarts of oil, but from experience,  anything over 8 quarts results in a belly full of oil. Because of cooling, I always fly between 8.5 and 9.5 quarts for longer flights,  and over time my Bravo settles at a 8 quarts. The engine doesn't burn any oil, I may add one quart of oil every 25-30 hrs. I constantly and meticulously check the wet head fittings for any leaks, there are none.

 I usually see a little oil on the front wheel gear door from the blow by,  but recently I was noticing oil slightly dripping on my front tire (approximately 3 to 4 drips). After doing more investigation, my mechanic found that I lost a bolt out of my scavenge pump when he was  changing the oil this week. I normally change my oil every 25 to 30 hours. All oil samples are normal.

 

He ordered a replacement bolt and another seal and will take care of it, but like any aircraft owner, it makes me concerned that maybe the overhaul shop did not torque the bolt, and it fell out or it was inadvertently left out during the last engine overhaul? 

Has anyone ever experienced losing a bolt out of their scavenge pump, resulting in an oil leak? What other the places to look for oil discharge from the TIO 540 AF1B besides the blow by, wet head fittings and 33 hose connection points?

 

 

[rbp]

1 hour ago, affricate said:

I make many cross-country flights, often from Arizona to Louisiana. I do know the POH states the Bravo requires 10 quarts of oil, but from experience,  anything over 8 quarts results in a belly full of oil. Because of cooling, I always fly between 8.5 and 9.5 quarts for longer flights,  and over time my Bravo settles at a 8 quarts.

 

my experience as well

[LANCECASPER]

10 hours ago, affricate said:

What other the places to look for oil discharge from the TIO 540 AF1B besides the blow by, wet head fittings and 33 hose connection points?

Valve covers, until I bought silicone seals for those covers from Guy Ginbey and got rid of my Lycoming gaskets.

[carusoam]

Great pirep affricate!

Let’s see if @M20Doc has seen that bolt come loose before… (M20M oil scavenger pump)

Best regards,

-a-

[mike_elliott]

I was told it is forbidden to use Loctite blue on some fasteners like Valve cover screws, intake screws, etc by the FAA by an IA. I question the wisdom of the FAA here, but what do I know? Yea, I am aware it can change torque readings...what other data points exist for not using it to keep the big thing up front glued together? A proper lockwasher and proper torque should stay fastened, but sometimes they dont as Clarence stated. Loctite does mitigate vibration loosening.

[Montreal]

I have not experienced that bolt falling out but I have experienced evidence of other loose fasteners in the same way—oil leak/misting. Our cowling design doesn't help much in the way of catching leaks on preflight but taking a peek every 25hrs helps. Rockerbox covers (oil drip), oil return lines near oil sump (oil drip), and top crankcase bolts (oil mist/film). Thanks for the pirep, will be sure to check my pump bolts. Safe flying! 

[affricate]

On 5/8/2023 at 3:47 AM, M20Doc said:

Lots of bolts, nuts and screw rattle out of these engines, it happens.  New bolt and lock washer and proper torque.  As for rocker cover screws, they seldom get replaced even though they have an integral lock washer, and lock washers are supposed to be one time use.

Thanks, Doc

[affricate]

On 5/8/2023 at 8:46 AM, Montreal said:

I have not experienced that bolt falling out but I have experienced evidence of other loose fasteners in the same way—oil leak/misting. Our cowling design doesn't help much in the way of catching leaks on preflight but taking a peek every 25hrs helps. Rockerbox covers (oil drip), oil return lines near oil sump (oil drip), and top crankcase bolts (oil mist/film). Thanks for the pirep, will be sure to check my pump bolts. Safe flying! 

Yep, always looking, and this drip showed up on the front tire. As always, I appreciate your input. 

[affricate]

On 5/6/2023 at 5:10 PM, LANCECASPER said:

Valve covers, until I bought silicone seals for those covers from Guy Ginbey and got rid of my Lycoming gaskets.

I really need to do this + that baffling, 

[affricate]

On 5/7/2023 at 9:23 PM, carusoam said:

Great pirep affricate!

Let’s see if @M20Doc has seen that bolt come loose before… (M20M oil scavenger pump)

Best regards,

-a-

@carusoamyou're all over MS, thanks for the input !!

[LANCECASPER]

44 minutes ago, M20Doc said:

His baffle material is fine, but his rocker cover gaskets are an un approved part.  I tried a set that he sent me on my RV4, the silicone deteriorated in hot oil.

Buy the Rear Gasket version from Spruce

I think you meant Real Gasket

https://www.aircraftspruce.com/catalog/eppages/siliconecalvecover.php?clickkey=8093

[affricate]

Just to update, the scavenge pump was removed and sent back to Airmark Overhaul where they overhauled the pump completely under warranty. A shout out to Lenny at Airmark Overhaul, who took care of the pump at no charge. There are zero leaks after the pump was reinstalled.  I have no more leaks (at the moment) 

 

Aramark overhaul completely overhauled my engine a few hundred hours back, and I have been extremely satisfied with their service. Good people.