N208ET

Well Known Member
I replaced the front oil seal on my crank. It had a one piece seal and I replaced it with a split seal. I was wondering if anybody has had any bad luck with split seals or horror stories.

Randy 8A
Flying
 
Only time you get a front seal "horror story", is when the breather gets plugged. Otherwise it's just ooze, no horror.
 
one piece installation procedure

Randy:

If it leaks again, you will find several posts that describe how to easily install a 1 piece. A Phoenix A & P added his special technique that made it even easier. If you cannot find the post, I am happy to email you the pics I posted before. I've done two 1 piece seals on different airplanes using Roger's idea and both are working fine.

Check for leaks frequently. Whereas a defective 1 piece will spin with the crank and leak, I don't know what a failed split seal would do.

I do know of one builder who sliced a 1 piece seal to make the installation easier. That was a mistake. It leaked almost immediately but remained in its seat.
 
There is a special sealant you should use also, can't remember the name right off the bat, but someone will know what it is... Mine was installed by the engine builder without sealant on the gasket and eventually it began to leak a little. Dripped from the cowling at the back of the engine, so it was hard to find. Finally traced the oil to the front of the engine but there wasn't much. I was definitely not convinced it was actually the nose seal since the area behind the flywheel was hardly damp at all. Pulled the prop and flywheel and the nose oil seal just pulled right out.

Put in a solid one (MUCH less expensive than a split ring) by heating the seal in oil and using a couple of large screwdrivers to lever it on. Installed the ring spring behind it, lathered on some of the sealant (whatever the heck it is called!) and pressed it in place. Hasn't leaked a drop since. Most surprising was how little the original leaked even with nothing holding it in place at all.

Regards,


Lee...
 
I put it in

I ended up using high temp RTV, a local builder has used that before, plus if I have to replace it again, getting the rtv back out of there won't be that bad. I flew around for 2 hours yesterday and so far no leaks that I can see. Hopefully that did the trick, thank for everybodies help.

Randy 8A
Flying
 
More thoughts and ideas...

Pliobond is what I used as a sealant.

That's the stuff! It goes between the seal and the case.

A good friend taught me to wrap a plastic bag over the flange and pull the 1 piece seal over it. The plastic bag serves as a lubricant enabling the seal to pass over the flange more easily.

After letting it sit, Roger also suggested a little Proseal laid across the face of the seal to the engine case surrounding it. That should further inhibit movement, leaks, and working loose. We were conspicuously careful not to get Proseal where it didn't belong.

No leaks and it's been 150 hours.