Speedbrake does not fully retract

[LANCECASPER]

38 minutes ago, TheBearFlies said:

So after reading this entire thread…mine need, clean and lube, rebuild, or cam adjustment. I think clean and lube is a good start.

Previous flight, SB worked perfectly.

Day of issue I flew from KGPM (Grand Prairie, just south of DFW) to 99V (Crawford Airpark CO). Plane was at KGPM for 3 days. First night it rained cats and dogs and when I went to depart there was a layer of dirt on my plane. Started at 8k, +2 hours 10k, +3 12k, +3.5 16k for crossing the Rockies. While level at 16k +15min I look out to the right and see this. Right SB deployed about 1/4 inch. I attempted deploying SB, no joy on both.

They did not work in the descent but then deployed after landing. The right would not stow completely but upon shutdown, stowed completely. 

Since your Ovation is a '97, if they haven't been overhauled and they aren't deploying it's probably time after 27 years for an overhaul.

[TheBearFlies]

So here is the conclusion. Removed, cleaned and lubricated. Both now deploy and retract normally. I do not think this has been done in years. I will now do this annually.

[Fly Boomer]

4 hours ago, TheBearFlies said:

So here is the conclusion. Removed, cleaned and lubricated. Both now deploy and retract normally. I do not think this has been done in years. I will now do this annually.

Thanks for the follow-up.

[TheBearFlies]

New follow up. Worked great for 6 months, then in October, not stowing again. Planned 30 days for the plane to be down in November and sent them into Precise Flight for the rebuild. Received them back in about 15 working days. Reinstall this week.

[dkkim73]

Let us know how it goes. What did Precise Flight charge? (I am assuming you have the newer type where you send the brain box as well)

Thanks,

David

[GeeBee]

1 hour ago, dkkim73 said:

Let us know how it goes. What did Precise Flight charge? (I am assuming you have the newer type where you send the brain box as well)

Thanks,

David

It is flat rate charge. $3999.00

[TheBearFlies]

Give me a couple weeks and I’ll post about install and performance. $1999 plus shipping.

 

 

[ArtVandelay]

New follow up. Worked great for 6 months, then in October, not stowing again. Planned 30 days for the plane to be down in November and sent them into Precise Flight for the rebuild. Received them back in about 15 working days. Reinstall this week.

I now use painters tape to cover the speed brakes when parked outside if rain is forecasted. Ounce of prevention …

[dkkim73]

44 minutes ago, ArtVandelay said:

I now use painters tape to cover the speed brakes when parked outside if rain is forecasted. Ounce of prevention …

Imagine looking over in a descent and going "now why aren't they going up? Oh yeah the tape...."

[M20S Driver]

4 hours ago, TheBearFlies said:

Give me a couple weeks and I’ll post about install and performance. $1999 plus shipping.

 

 

$2K for both or one?  

[TheBearFlies]

2 hours ago, ArtVandelay said:

I now use painters tape to cover the speed brakes when parked outside if rain is forecasted. Ounce of prevention …

Speed tape not Painters tape!

[BFF78]

Same issue on my 95 Ovation- left side no issues- right side slow to retract with .5cm protruding.LPS lube sorted it out. 

[LANCECASPER]

9 minutes ago, BFF78 said:

Same issue on my 95 Ovation- left side no issues- right side slow to retract with .5cm protruding.LPS lube sorted it out. 

The Precise Flight documentation says, "DO NOT USE SPRAY LUBRICANTS!", but only Aeroshell 22

[TheBearFlies]

On 1/7/2025 at 6:11 PM, M20S Driver said:

$2K for both or one?  

Both

[Marc_B]

I’ve looked into service before. I wish they’d also repaint and return like new for that price. But these days that’s the only way you can get replacement return springs as PF doesn’t sell them individually any more.

@TheBearFlies keep us posted what was replaced vs just cleaned and lubed when you get them back. 

[GeeBee]

I wonder why the 100 series are 1999 but the 2000 series are 3999? How much difference can there be?

[TheBearFlies]

When I contacted them they stipulated that you have to send in both. They will not rebuild one.

[Marc_B]

1 hour ago, GeeBee said:

I wonder why the 100 series are 1999 but the 2000 series are 3999? How much difference can there be?

The 2000 series has an asymmetric logic control unit "ALC" that prevents deployment of only a single side.  The 2000 series is more "complex" and my guess is that there are more parts that are checked and replaced.  But I believe that the asymmetric deployment unit is origin of requiring both speed brake units as well as the "logic" unit, so they can test them all.

The 100 series are pretty basic with a motor connected to a worm drive that actuates two cams that deploy the brakes against spring resistance from the return spring.

[Marc_B]

On 1/7/2025 at 7:41 PM, LANCECASPER said:

The Precise Flight documentation says, "DO NOT USE SPRAY LUBRICANTS!", but only Aeroshell 22

It's the worm gear / pinon gear that needs to be maintained and lubricated.  PF says that if you use spray lubricant that you "wash out" the grease that's crusty, but that it won't leave lasting protection.  So there's more resistance in the worm gear/pinon gear due to crusty grease, but then (since the units are open on the top and have the ability to get rain, wash water, spilled fuel, etc. into the units that no grease protection leads to corrosion of the worm drive and more problems down the line.

You have to remove the units to really get the drive gears clean, but you can reach the worm drive from the top of the unit with a standard acid brush and a light amount of grease (Aeroshell 22) as noted.  BUT, I've been told that you only want to use a light amount.  If you apply a heavy grease booger it just sits there and gets crusty and causes issues down the line.

I wager that probably a small amount of speed brakes in the field get routine maintenance/lube annually.  I suspect that most mechanics don't lube these annually unless the owner asks for it.

 

For failure modes: what's been shared on MS usually is corrosion and failure of the return spring (it breaks).  But if you don't lube them then you can have the motor wear out or causes issues with gears.  Those two things are usually replaced at PF overhaul I believe.  For those with the 100 series, here are some good documents to have in your files...

000S001D_Rev B_Drawing Package_08_14_2014.pdf 100 Series ICS.pdf 100 Series Comprehensive Overhaul Service.pdf 100 Series SpeedBrake Repair Service 7.22.21.pdf

[PilotX]

32 minutes ago, Marc_B said:

I wager that probably a small amount of speed brakes in the field get routine maintenance/lube annually.  I suspect that most mechanics don't lube these annually unless the owner asks for it.

I agree. Debating pulling mine out to do it muhself.

[LANCECASPER]

1 hour ago, Marc_B said:

It's the worm gear / pinon gear that needs to be maintained and lubricated.  PF says that if you use spray lubricant that you "wash out" the grease that's crusty, but that it won't leave lasting protection.  So there's more resistance in the worm gear/pinon gear due to crusty grease, but then (since the units are open on the top and have the ability to get rain, wash water, spilled fuel, etc. into the units that no grease protection leads to corrosion of the worm drive and more problems down the line.

You have to remove the units to really get the drive gears clean, but you can reach the worm drive from the top of the unit with a standard acid brush and a light amount of grease (Aeroshell 22) as noted.  BUT, I've been told that you only want to use a light amount.  If you apply a heavy grease booger it just sits there and gets crusty and causes issues down the line.

I wager that probably a small amount of speed brakes in the field get routine maintenance/lube annually.  I suspect that most mechanics don't lube these annually unless the owner asks for it.

 

For failure modes: what's been shared on MS usually is corrosion and failure of the return spring (it breaks).  But if you don't lube them then you can have the motor wear out or causes issues with gears.  Those two things are usually replaced at PF overhaul I believe.  For those with the 100 series, here are some good documents to have in your files...

000S001D_Rev B_Drawing Package_08_14_2014.pdf 4.49 MB · 2 downloads 100 Series ICS.pdf 422.65 kB · 2 downloads 100 Series Comprehensive Overhaul Service.pdf 427.15 kB · 2 downloads 100 Series SpeedBrake Repair Service 7.22.21.pdf 332.55 kB · 2 downloads

Exactly!

 

 

[Lax291]

37 minutes ago, PilotX said:

I agree. Debating pulling mine out to do it muhself.

I have the 100 series and pulled them out to clean, lube with Aeroshell 22. and set the up/down limits so they would fully retract.  Was very easy to do and if you are at all mechanically inclined you should have no trouble.  If you have the same series and run into any questions, happy to assist if I can.

[Marc_B]

@LANCECASPER it makes me laugh how many times the same thing is said in the same thread, in different threads, in different ways...would be fascinating to see a 1000 mile overview of Mooneyspace.

Perhaps one of these days AI will allow you to type your question on Mooneyspace and will give you an answer and link the pertinent resources...oh wait, google does that already!

It would be interesting for someone to "curate" all the knowledge from MS into an organized searchable "book"...almost like a POH, MAPASF PPP, IPC, Service Manual, AFMS.  There are so many little pearls hiding in the threads that you sometimes have to look at "all the threads" to glean all the knowledge!

I will often cut and paste info that I find that "might be important" sometime down the road...i.e. for SB I previously copied:

"PF SB motor is a Pittman #GM8712-21, call 866-287-3786 I think his name was Denis.  Specs 19.5:1 ratio/19.1 volts, you will have to reuse the mounting bracket from the old motor, getting the old gear off is tough the set screw may have to be drilled and taped. That's the hard part, the rest is easy.

Lubricate worm drive and worm wheel with Aeroshell 22 only."

 

[PT20J]

At least on the 100 series, the #8 screws on the top of the wing are threaded into tapped holes in the aluminum frame that only catch a couple of threads. For something that the manufacturer believes should be removed annually, rivnuts would have been a better choice. Some of mine have been drilled and tapped for #10 screws.

[GeeBee]

My 2000 series has nut plates under the skin to run the screws. That said, I don't see how adjusting a pot on an electronic board for "asymmetric control" adds 2000 bucks to the service, but I remain to be convinced.