Oil Leak

[jkon]

I have a Briggs & Stratton 7.75H.P. engine on my Craftsman snow thrower that is leaking oil. Engine model number is 12C314-0131-E1. Engine is 15 years old but still runs like a top. Oil is pooling at the front lower corner where engine is mounted to frame. I cleaned the engine up thoroughly to try to pinpoint. I originally thought that the front PTO side oil seal was the culprit but that is not so. The definite area is the area that I originally mentioned. Could it be the rear oil seal (flywheel side) which I cannot see? I am pretty handy as I changed both belts and idler wheel yesterday and as you all know that is not the most easy job...splitting the snow thrower to change the belts and taking the drive apart to change the idler wheel. Hope I did not waste my money. That would have been the time to pull the engine to take a closer look but did not want to go through all that trouble before asking you all. Maybe it is time for a new snow thrower??? Thank you all for any help that you can provide.

 

[old1]

Without seeing it in person, it sounds like it is probably the sump, or crankcase cover gasket that is leaking. If so, And you have the ability to do it yourself, the new gasket is very cheap. Personally, if it was mine, I sure wouldn't buy a new one just because of a little oil leak. But that is just me, maybe you are just looking for an excuse to rationalize buying new. Which I understand. I have done similar myself.

 

[CT8]

Is the crank case over filled?

 

[jkon]

Thanks for the reply Old1. The oil is more than just little. When I got the snow blower out of storage from the shed there was an oil ring on the shed floor 18 inches in diameter. When I removed the belly pan from the blower it was all covered in oil. The drive pulley and friction wheel were all oiled up as well as all surrounding areas in there. It definitely is not the crankcase cover gasket. I cleaned that all up and no fresh oil in that area. Where is the sump on that engine? I have a parts plow up and I don't see a sump. After cleaning it up and restarting I can see oil seeping in the front corner towards front of engine between the bottom of engine and frame. Definitely coming from underneath the engine...between the frame and engine. Could the block be cracked underneath? The only other thing I may try is the threaded oil drain pipe out the rear of the engine. When I do the oil change I am going to remove that drain pipe from the engine and put some fuel proof tape on the end screwing into the engine.

 

[jkon]

No not overfilled CT8

 

[jkon]

I know it was leaking oil all last season while using it and am sure that helped splatter it all over the place underneath.

 

[jkon]

The engine is a Briggs Intek Snow Overhead Vlave. Model 12C314-031-E1

 

[BrianF]

Start pulling things apart to get a better view.

 

[Eddie]

Check the valve cover gaskets. Ed

 

[jkon]

Purchased front and rear seals plus crankcase gasket. I had the day off yesterday. Drained gas and oil then pulled the engine off. First thing I checked was for a cracked block underneath. No crack thank goodness. Really inspected engine and could find no oil leak evidence anywhere. Pulled the crankcase cover and changed the seal. No evidence of oil leak. I was surprised how super clean everything inside the crankcase was. Probably because I change the oil every year. Proceeded to rear. Flywheel came off pretty easy. Changed that seal. No evidence of oil leak. Really took a close look at rocker cover area. No evidence of oil leak but am going to check and adjust (if needed)valve lash since I bought a new gasket for that too. Rear and both side drain plugs show no evidence of oil leaks. I am stumped. I still have the engine on the bench in semi-torn down state. Before I put the crankcase cover back on is there anything else you can think of before I put it back together? Could it be oil from when I tilt the thrower forward and set it up on the auger housing that oil leaked over the years and built up on everything? But where would that oil be coming from? I tilt it up at least once every season. Now I feel like I cried wolf for nothing! It just bugged me as the thing didn't leak oil for at least ten years. Thanks!

 

[old1]

I would put the engine back together, then fill it with oil, and watch it for a few days to see if there is any seepage. Maybe it only leaks while running? Maybe from the crankcase breather?

 

[jkon]

Yes Old1. I only saw it puddling fresh oil up toward front of frame and engine block while running. Once I stopped engine and wiped it clean, it would not appear again until I started the engine again.

 

[JTK]

That's a weird one jkon, but like you say, given how these things sit in the off season, the block, engine, etc may not show traces of the leakage as it's all run down hill from sitting. I'd be surprised if it was a crank seal at either end because the oil level should be lower than those seals when the machine is sitting.

Could the leakage happen after flipping the machine over into the service position? Absolutely. Oil can fill the valve cover area and then can pour out the breather tube onto the frame.

Like said above. A long slow oil leak over the off season, my guess would be the crank cover gasket.

That's a pretty old Briggs OHV machine. Pretty close to when they first started using them on snowblowers. I know when I bought my Yardman with a 7hp Tecumseh OHV in 1999-2000, it was a rare find and new for the time period.

 

[jkon]

All done. I pulled valve cover off and it is a good thing I did. Valve adjustments were off quite a bit and one of the nuts was lose when I went to adjust them. Got the whole thing put back together.Torqued everything as I had found all torque specs on line. Installed new belts and friction wheel. Serviced sticking electric starter which I do not use very often. Got it all back together and reinstalled on thrower. Started 2nd pull. Ran it for a good 25 minutes and no leaks. So if anything besides knowing for sure that the block is not cracked, its got some new parts...both seals, crank gasket, valve cover gasket, muffler gasket, belts, friction wheel. Belts and friction wheel I had bought a couple years ago for spares. Cleaned it all up and should be good to go for the winter. Thank you all for all your help!