Champ oil leak

R

Rickw

Well-known member
Joined
Dec 19, 2022
Messages
131
Location
Milford,DE
hey guys,my champ 7ac has minor oil leak.Crank seal 65-8 tapered shaft single piece seal.How bad to replace.Thanks in advance,Rick
 
Easy. The secret is the correct tools.
I note that the seal itself is a standard part - last I checked $24. Many years ago Continental sold them for $75. Check out AC 23-27.

The first tools are for removing the prop hub. They don't usually just pop off. Get some brass shim stock and stuff it in under the snap ring that holds the nut. Machine an aluminum button to fit the nut and enable you to give it a good tap with a big mallet.

Then put some force on the nut with a two foot steel bar - maybe tap it gently with that big hammer. Stick the aluminum button in the nut and give it a moderate "whap." Hub should then be loose.

The old seal is not going to come out in one piece - carefully cold-chisel it out. Be careful to not damage the case or crank - just go all the way around the seal, and remove it in two pieces.

Check the crank for damage - then lubricate the crank, put some sealer around the outside of the seal, and tap it into position. To get it in straight, consider an aluminum tube and a plywood washer. If I remember, I will get a photo.
 
Top photo - not sure what the white plastic tube helped me do - the aluminum tube and the plywood washer are for inserting the seal evenly. The button is shown inserted in a prop hub nut - you can see it laying on the right in the lower photo. The ridge keeps it centered while you whack it with the big mallet.

The strange thing with four bolts was used to get a hub off, where the snap ring ridge had totally failed. Still a good prop hub, but without this tool it would not come off. I think there was another piece that went across the front; not sure. The basic idea is the same as a steering wheel puller.

The aluminum ring did something at one point, or I wouldn't have kept it with these tools. And I forgot to include the brass shim, which had fallen when I grabbed these things off the shelf.

Hope this helps - all you need is that button and a big hammer, usually. But always stick a shim in between the snap ring and the nut prior to adding removal force.
 
Hey Bob,got my seal from e-bay,$16.62 shipped,lol.Ordered from e-bay,it was shipped and delivered by Amazon(?) in 2 days.Making my tools now to make things easier,thanks again
 
UPDATE: just want to update everyone.Replaced oil seal,completed annual,test flown a couple hrs,everything great,no more oil leak.Just want to give Bob a special thanks for all his help about tools and the oil seal,you saved me a bunch of money,thanks again Bob.
 
Mr. Turner , I’m sure that I’m not alone when I say that I hope that you never get bored or uninterested in participating on this site !
 
What has happened is that I would rather sit on the couch than turn a wrench. Part of that is laziness, but the other part may be that I am well into my ninth decade.

I make stuff. So far this year I am working on a brass model steam locomotive, have two brass cast Diesel train units to paint, and am putting heel brakes on a Pietenpol. But at the four hour point I can feel the couch calling me.

Today? 19 Stearman landings and a half a beer. And I am done!

I need a good book, instead of an iPad.
 
Bob Turner said:
What has happened is that I would rather sit on the couch than turn a wrench. Part of that is laziness, but the other part may be that I am well into my ninth decade.

I make stuff. So far this year I am working on a brass model steam locomotive, have two brass cast Diesel train units to paint, and am putting heel brakes on a Pietenpol. But at the four hour point I can feel the couch calling me.

Today? 19 Stearman landings and a half a beer. And I am done!

I need a good book, instead of an iPad.
Click to expand...
thanks again Bob for helping me out
 
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