Wemac air vents in Ovation

[FJC]

Has anyone done a diy repair or does anyone have pictures of the airvent assembly and/or part numbers? I have 1 where the pin has fallen out and it seems simple but one never knows...Now that it is getting hotter during the day, good air flow will be handy!

Thanks.

 

Freddy

[squeaky.stow]

Hi Freddy, Are these the overhead air vents you are talking about? If so, I went through this recently with my 252. Older but similar. Repairing them is fairly easy, but getting access to them is a huge PITA. Let’s talk about the easy part first. The butterfly valve is opened and closed by turning the outer ring of the nozzle which turns a ring clip that has a u-shaped tab with a slot in it. A little rod attached to the butterfly valve sits in this slot in the tab and as the ring clip turns in the housing, the changing geometry opens or closes the butterfly valve. See first picture. There are actually two parts to the ring clip that both fit in a circular slot around the inside circumference of the housing. There is a spring clip that looks like a bent bicycle rim that keeps tension on the assembly, then the ring clip with the u shaped tab. Both sandwich into the little circular slot, but if the ring clip falls out then all the pieces just rattle around inside the vent. Once you get the vent out of the plastic housing it is very easy to reassemble and put a drop of Loctite on the ring clip to keep it secure.

 

Now for the hard part. The vent assemblies are attached to the back side of your headliner and the metal Wemac valve is inside a black plastic housing. In my case I had the headliner out for an avionics upgrade so that was my opportunity. For the first one I cut the entire housing out of the headliner, only to discover that the metal valve is actually glued into the black housing so I still couldn’t get it out, and the offending ring clip is on the back side of the vent, inside that black housing. I actually had to cut the housing in half to get access to the back of the vent, but it was easy to glue it back on with plumbers ABS cement. For vents 2, 3 and 4 I left them in the headliner and just cut the black housing. There was no point in cutting them out of the headliner. In picture 3 you can see the vent with the housing cut open and the loose ring and spring clips. In the last picture the housing is glued back on. You can see the cut line.

 

Your part numbers are different from the 252 so your valves and housings won’t be identical but they look very similar from the pictures in the IPC so I think your job should be similar. 
Regards,

Mark

[FJC]

What a treasure trove of information!!! Thank you for taking the time to write this up. I'm going to study it further and see if I wanna tackle it.

[donkaye]

Freddy, from Mark at Top Gun:  Mooney has the part.  It costs $115 and its 2 hours labor to replace.  It hardly seems worth it to do it yourself.

[squeaky.stow]

I don’t know much about the Ovation. Is it possible that you can remove the vent assembly from the center of the headliner without taking out the headliner itself? 
If so that labor estimate would make sense. For my plane you had to remove the entire headliner, which was a lot more than 2 hours. 
Once I had it out, the vents were pretty easy to fix and even if I had bought new ones, I would still have had to cut the old ones out and glue the new ones in. 
It struck me as a poor design that there was no way to remove and service them without cutting things apart. Maybe they improved on that with newer models?

[carusoam]

Great details with pics, Squeaky!

Thanks for sharing all of the details...

Best regards,

-a-

[squeaky.stow]

Shout-out to @Jim F

He did it first and showed me how the Wemac vents actually work. That gave me the courage to try the DIY repair while the headliner was out.

Once you make the first cut it’s too late to turn back!

[Jim F]

Hi squeaky.stow,

Thanks for the shout-out....

The repair of the Wemac vent was fairly simple once the head liner was out.

I tried to remove the hat assembly with a razor blade but the ABS headline is super thin and I was very concerned I could damage the cosmetic side.

I used a Dremel to remove the hat then removed the rivets and disassembled the eye ball.  The snap ring had popped out of the grove.  I reinserted the ring and put a dab of Loctite on it.  I coated with spray silicone as a lube and reassembled.  The hat assembly needed some kind of reinforcing so I made the gussets out of thin ABS sheet and used ABS glue.  I sealed with thin coat of RTV after the ABS glue was dry.

 

Enjoy, Jim F

[squeaky.stow]

5 hours ago, Jim F said:

Hi squeaky.stow,

Thanks for the shout-out....

The repair of the Wemac vent was fairly simple once the head liner was out.

I tried to remove the hat assembly with a razor blade but the ABS headline is super thin and I was very concerned I could damage the cosmetic side.

I used a Dremel to remove the hat then removed the rivets and disassembled the eye ball.  The snap ring had popped out of the grove.  I reinserted the ring and put a dab of Loctite on it.  I coated with spray silicone as a lube and reassembled.  The hat assembly needed some kind of reinforcing so I made the gussets out of thin ABS sheet and used ABS glue.  I sealed with thin coat of RTV after the ABS glue was dry.

 

Enjoy, Jim F

Hi Jim,

So when you drilled out the rivets, were you able to just pop the eyeball vent out of the housing? In my case I drilled out the rivets but found that the vent was firmly glued into the black plastic housing. I couldn’t understand why Mooney would go to the trouble of gluing AND riveting them in place. 
My headliner had been removed and recovered in the past, so maybe someone did some work then, but there was no evidence of the vents having been cut out before.

Cheers,

Mark

[Jim F]

15 hours ago, squeaky.stow said:

Hi Jim,

So when you drilled out the rivets, were you able to just pop the eyeball vent out of the housing? In my case I drilled out the rivets but found that the vent was firmly glued into the black plastic housing. I couldn’t understand why Mooney would go to the trouble of gluing AND riveting them in place. 
My headliner had been removed and recovered in the past, so maybe someone did some work then, but there was no evidence of the vents having been cut out before.

Cheers,

Mark

Hi Mark,

I don't remember my vent being glued.  

Jim