Briggs 287707 oil leak from top seal

[bl8tant]

Finally made it over from the old PERR forum. Looks like quite a few made it over here...

Anyhow - I have a Briggs 14.5 hp I/C Quiet series vertical shaft (Model 287707-0220-01) that is leaking from the top seal (only). I don't know the history of the motor,but it had been leaking there when I got it (lots of hard oily crud build-up under flywheel and down sides).

It starts easy, runs great, no smoke (maybe a puff on start-up if you choke it). I just replaced the top seal and test ran it - still weeping.

So far I have:

1)Replaced both flywheel and sump seals
2)Leak-down test seemed OK - Some air getting past rings, but seemed normal. Valves were air-tight.
3)Manometer check - pulls about 10" of vacuum so breather must be OK ???
4)Oil level is OK (new oil) and no fuel contamination
5)New air filter
6)Adjusted valves to spec

I'm out of ideas. It does not vibrate (nothing bent), and there were no scratches or galling around the seal area. What the heck is going on ?????!!!!

[StarTech]

Have you checked the play in the magneto side bushing?

[bl8tant]

Not really. I tried rocking the flywheel and didn't notice any play side to side. Vertical play (endplay ?) was barely even noticeable as well. When I had the sump off to replace the sump gasket everything looked good too (no sludge or anything, cam lobes looked good, pto shaft had no marks,etc.)

Unfortunately I don't have the plug gauge to check it. The IPL shows a bushing/seal kit ($10), but I've never replaced one. Is it pressed in/out or does it require some special tool ?

[RoyM]

If the seal is pressed in too far it may be blocking the drain back hole.

[bl8tant]

That's a good suggestion. The seal I removed was flush with the case, so I installed the new one the same depth. How far down would it need to be to interfere ?

[Pete in Milton]

You mentioned oily black crud at the top end , if the seal is not blocking the drain back maybe the oily crud is???

[Deere2me]

That's a good suggestion. The seal I removed was flush with the case, so I installed the new one the same depth. How far down would it need to be to interfere ?

Flush is fine on that motor. You say PTO shaft looked good, BUT no mention of mag shaft condition. It could be scored, nicked , grooved, etc. Even a slight defect can cause it to seep. All the crud you mentioned has grit in it which could cause the grooves etc. Pull the seal, toss it, and double check the shaft condition, if your careful, you can clean it up using 600 or finer wet/dry paper. If its really bad, they make speedi-sleeves to cover worn seal areas, but I have had luck seating the seal deeper. Pay attention to the drain hole( if any).
If your not sure of side play, one trick is to spray the shaft /bushing contact area with a shot of carb cleaner to remove/reduce the oil film and then check it. Obviously, ya wanna make sure you have the area CLEAN of any dirt etc.
Drop a little oil on it before you button it up, though.

As for the bushing kit, yeah, its pressed in. Sounds like you need to snag a manual , from the old forum mayhaps.

[mwerles]

check the breather again,if it is not relieving crankcase pressure that may be forcing oil past seal.I have yet to see a mag end seal fail,the pto seal seems to fail quite often,but anything can happen.
Les

[KE4AVB]

check the breather again,if it is not relieving crankcase pressure that may be forcing oil past seal.I have yet to see a mag end seal fail,the pto seal seems to fail quite often,but anything can happen.
Les

I seen a couple here leaking but it was flywheel side bushing that was worn out causing the leak. Actually the engines didn't have the replaceable ones but they were offered for replacement. Had to reamed for the bushing to fit in and then bushing had to be reamed on one so the crankshaft would turn freely. None of which was mentioned the repair manual that I could find; just knew to do it from working on "73 IH truck king pins.

[bl8tant]

Sorry guys - I was away for a couple days and just now getting around to replying.

Just to clear up a few things : The first thing I did was completely clean the motor (spotless). The mag end shaft has been inspected (looked fine). No obviuos play in the shaft. Breather is fine (see manometer reading in my first post). Etc,etc.

Now for the good news......I think it quit leaking ! After I replaced the seal and ran it (5 minutes or so) there was a small amount that ran out from under the flywheel. Then I posted on here.......and have been busy since. So today I pulled the flywheel to double- check things, and cleaned it all up really good again. Buttoned it up, started it and let it run for a good 40 minutes. So far so good ! I'm guessing that the new seal must have leaked for a few seconds on first start-up and then quit leaking (which led me to think I still had a full-time leak).

I know one thing.....even a TINY leak of new 5w-30 full synthetic oil can travel a long ways and looks like more than it is.

Again -THANK YOU all for replying and I have few more ideas for future troubleshooting thanks to your suggestions. Sorry this one may have been a wild goose chase. It may leak again and COULD still be the bushing and if it is....I'll bite the bullet and replace the stinkin thing