Vacume pump removal

[jrthomas]

I have a 912ul that came on a partially built Model IV with a vacume pump installed. I've decided not to use it but I'm unsure about removing it. I know that for it to be installed that extra parts were installed in the gear box. A Rotax repair center said I should be able to remove it without any problems, that it shouldn't leak. I would feel better if I, at least, have a cover to go back where the pump was installed.(Is a cover available?) I can leave it in place but I would rather remove it to save weight. If any of you have knowledge of what's involved I would sure appreciate your advise. Thanks, James Thomas

[Dorsal]

My 912s is configured for a vacuum pump though I have not and will not install one. I have run the engine without it which seems fine though I will eventually cover the opening. If they sell one, great , if not I expect a simple flat piece of aluminum with for holes drilled in it will suffice.

[IVPleasure]

I am not familiar with the 912 but for certified engines there is a plate and gasket to cover the hole when the drive pad is not used. Aircraft Spruce might have them.

[MotReklaw]

Hi James,
I had the same issues with my 912. I wanted to remove the vacuum pump. There is a thread on this at http://forums.matronics.com . Look in the Rotax section.
Basically, you have to remove the gearbox using a puller and remove the gear that drives the vacuum pump. There is a guy named Roger on that forum that you can contact as well. He is a smart guy. He said it was a simple task and wouldn't take long to do. I haven't done it yet. He even posted a homemade puller that you can make.
Hope this helps,
Tommy Walker in Alabama

I have a 912ul that came on a partially built Model IV with a vacume pump installed. I've decided not to use it but I'm unsure about removing it. I know that for it to be installed that extra parts were installed in the gear box. A Rotax repair center said I should be able to remove it without any problems, that it shouldn't leak. I would feel better if I, at least, have a cover to go back where the pump was installed.(Is a cover available?) I can leave it in place but I would rather remove it to save weight. If any of you have knowledge of what's involved I would sure appreciate your advise. Thanks, James Thomas

[jrthomas]

Thank all ya'll for your input. To Tommy in Alabama, Is it necessary to remove anything in my gearbox if I remove my vacuum pump? My Rotax man says no, just remove it and the gear is sealed so it shouldn't leak but he has never done this himself. I planned on making a cover if I remove the pump or, if it's going to get complicated, just leave the pump on with the air filter. It's not worth the effort to me to go into the gearbox. Thanks, James Thomas

[Dorsal]

You do not need to go into the gearbox, just remove the pump and optionally cover.

[jrthomas]

Thanks Dorsal. Advise taken.

[MotReklaw]

Thomas,

Are you on the Forums.matronics.com Rotax list? Roger Lee, who I respect highly dealt with this issue with me several months ago. He said there is a gear in the gearbox that should be removed if you are not using the vacuum pump. Roger is a certified Rotax technician whom I trust. I am not disputing the other poster here, but if you look at the matronics list and read Roger's posts you will see that he is very well qualified.

Again, not disputing someone else's post, but just wanted to post this so you could consider all options. Also, you might want to call Lockwood Aviation in Sebring, FL and ask them.

Take care,

Tommy Walker in Alabama
N8701 and N8701T (both Rotax 912ULS powered)

Thank all ya'll for your input. To Tommy in Alabama, Is it necessary to remove anything in my gearbox if I remove my vacuum pump? My Rotax man says no, just remove it and the gear is sealed so it shouldn't leak but he has never done this himself. I planned on making a cover if I remove the pump or, if it's going to get complicated, just leave the pump on with the air filter. It's not worth the effort to me to go into the gearbox. Thanks, James Thomas

[Dorsal]

Hey I'm certainly not above learning something new, did he give a reason for needing to remove the gear?

[jrthomas]

Since there is a question whether or not I need to remove the gear from the gearbox, I left the vacuum pump in place with hoses and filter. The pump, I believe, only weighs about 1.75 lbs so it's not a big deal weight wise. I removed the artificial horizion and directional gyro. I haven't weighed them but they are fairly heavy. Thank you all for your help, James Thomas