I replaced the crank seal when I replaced the crankcase gasket that was leaking. After the first cut I noticed it started leaking again, when my dad put it on he nicked it so I figured that was it, I bought a new gasket and put it on myself, it went on perfect, I used the old seal to beat it in and it sealed perfect around the crank. I cut the grass the other day and when i was cleaning it I noticed alot of oil in the center of the engine. Now it's so bad that my drive belt is slipping and the mower doesn't move easy. I already ordered the seal, yes it's a briggs and straton factory part, engine is a Briggs 25hp. Just wondering if anyone else has had problems like this and have an idea? Only thing I can think is maybe a rough spot on the crank is cutting it. Will be taking engine out soon. Thanks
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Any ideas on why a crank seal would be leaking after replacing twice
- Thread starter stang8689
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Export threadMy local service tech told me they are finnicky at best. When I replaced one last year on my dad's mower, the tech told me not to be disappointed if it leaked and I had to come get another one. He said if they are not put on perfectly, they will leak. I guess I got lucky as it doesn't leak. All I did was to make absolutely sure the seal went on straight and everything was operating room clean.
Have seen several engines where the crankshaft gets a groove worn into it as well as egg shaping the bearing in the sump. Either due to excessive belt tension or faulty electric clutch that is grounding through the crankshaft causing an arcing effect through the oil film causing a rough surface.
I always install seals with assembly lube. I also put a micro fitch card around the shaft so I am sure not to nic the seal when assembling. The seal slides easily and the card pulls right out.
I had one this spring where I ended up putting in four seals, blew out the first three. Finally found that the problem was a plugged oil return line.
I put another on and still leaking, I was wondering where the oil return line is so I can check it, it's not where you drain the oil is it. The crank has a small nick just under where the seal sits, I sanded it down some but thinking that may be the problem. Reason I ask about the return line is the seal looked to be more blown out then ripped. I will be trying to fill the nick with some JB weld or if someone has a better idea, the crank looked brand new besides that with no grooves
Just reread your post and I'm sorry I gave you bad info. Just noticed that you are talking about a vertical engine and mine was horizontal. You will not have a return line. I do have a few questions though. Is the seal leaking on the crank area or the block area? Have you checked to see if you have excess crankcase pressure? Can you post the model numbers of the engine, all three? I think I have some ideas, but I made a mistake earlier and don't want to do it again. Sorry, waiting for a reply. Rivets
The engine number is 446777-0106-e1 the seal is in the crankcase, it's the crankshaft seal that goes over the crank. The original leak was from the crankcase gasket, the crankshaft seal wasnt leaking, I replaced it to be safe. I ordered another seal im going to try to fix the nick with JB weld and sand smooth. I did have a hard time getting this seal in, I will try assembly lube this time