912 water pump weeping

[Wheels]

My 912 F series is weeping at the water pump weep hole. Anyone ever change a water pump? I looked in the book and it calls for special tools and partial engine removal and partial electrical system dissasembly ... is it really that complex?
I know, I know, "never feel sorry for a guy with an airplane."

[DesertFox4]

Wheels, how much is it leaking. I had a 912 that would weep a drop or two every couple hours of operation. That went on for a couple years.

[Wheels]

Last summer It was leaking a few drips after shut down and never anything significant and then day before yesterday it became very noticable with water collecting on the exaust manifold and dripping on my floor. Probably about a half dollar sized puddle today. I figure its just going to get worse and I may as well tackle it while the engine is loose for the vibration isolator replacement.
I called Lockwood and ordered gasket, oil seal, water seal, etc. Lockwood rents the special tools so you don't really have to buy them. I am working with an A&P mechanic who I trust. Any advice?

[HighWing]

I had issues like that for a time years ago. I contacted one of the service centers and they suggested Bars Leaks added in the proper proportion to coolant volum. Never leaked again.
Lowell

[wwillyard]

I replaced the seal in my 912 several years ago at the first detection of a leak. I could not see any evidence of seal degradation upon removal. I suspect that there must have been some contamination on the seal mating surfaces. Installed new seal and switched to Evens water less coolant and have observed no leakage since. I can't say what caused the problem or if the choice of coolant is a factor either way. Should the problem show up again I would certainly try every solution I could before replacing the seal, removing the engine is no fun.

[Wheels]

I wish I could ignor the little leak, but that wouldn't be a realistic approach. Leaks get worse not better and this one is worse today than when I first discovered it, so there aren't any options other than to fix it.

There aren't any repair facilities for Rotax within hundreds of miles so there aren't any options except to fix it here.

The pump can't be accessed without pulling the engine so there aren't any options except to pull the engine,

The mechanic who I hired to do the job is letting me help so I am learning a lot before I go to the repair school next month.


The only option I really do have is ... cash or check.


dissassembly wasn't too tough. Lots of hoses, connectors and cables. The mess is minimal and the reward will be knowlege, mechanical integrity and safety. Aviators need all three in spades.

The engine is on the hoist tonight, I'll let you know how it goes when the special tools arrive.

[DesertFox4]

The mess is minimal and the reward will be knowlege, mechanical integrity and safety. Aviators need all three in spades

That's the attitude to take Wheels. Best of luck with the repair. Hope you're back flying soon. Let us know how you fared.

[DBVZ]

I had issues like that for a time years ago. I contacted one of the service centers and they suggested Bars Leaks added in the proper proportion to coolant volum. Never leaked again.
Lowell
Sounds like he is a little past the time to have tried the Bars Leaks. That would still seem to be a valid first step. It may be worth more discussion of it, if anyone has any reservations about introducing Bars Leaks into an aircraft cooling system.

[Dorsal]

That's the attitude to take Wheels. Best of luck with the repair. Hope you're back flying soon. Let us know how you fared.

Couldn't agree more, attitudes like that move that stats in a good direction :)

[Wheels]

Ok, I think I can close this thread.
The water pump seal was bad, we removed the pump and replaced the impellor with the new style, a new water seal, a new oil seal and reassembled the engine. The rubber components on the Lord Mounts were shot and were allowing excess vibration. They were replaced.
The fuel system didn't have a vent line, we installed one.
The fuel system had no back up fuel pump, we installed a facet fuel pump.
The excessive vibration was causing fuel to dump overboard at idle. That problem is gone. The engine produces full power and it idles like a kitten at 1700 to 1800.
The gearbox was inspected and found to be within limits although the springs were allowing some slipping. We replaced the springs and the gearbox is like new.
The total time to do all of the upgrades, (some not mentioned) was 39 hours with two men. (one of them competent)
I flew home tonight after six months of chasing ghosts. There is an upside to the whole affair that I can appreciate more than my wife, I know more about the mysteries of the Rotax engine than I could have learned in a decade of flying. In fact, there are no mysteries, only troubleshooting diagrams that haven't been written ... yet.
Thanks for all the great support and a special thanks to John Mcbean who called me names when I put my plane up for sale out of frustration.

Lastly, during the final phase of repair, I attended the Rotech research school and spent 50 hours with wrenches in hand and books in my face. They know the drill and when you complete the course, you will too.
Wheels.

[DesertFox4]

Wheels, thanks for the wrap up on your "ghost chasing". So glad you are more familiar with your power plant. Gives you confidence and your family peace of mind. Rotax schools are worth every penny.
After years and a couple thousand hours behind Rotax four- stroke engines I'm still learning things. Your post brings one thing to mind. The rubber engine mounts. This is an item that can adversely affect the proper operation of a Rotax engine and yet can be easily overlooked when a rough running situation occurs. Glad you checked the gearbox also as this was a problem in my 912S at about 450 hours. It made for some violent engine starts until diagnosed.

Wishing you many trouble free years of Kitfoxing. You deserve a perseverance award.;)