Serious oil leak

[rswartz]

Well, I finished mowing the lawn this evening, pulled the 1711 up to the garage to blow off the grass and found oil dripping onto the front of the deck. Checked the oil level and found only a drip on bottom of dipstick. Pulled the hood and saw some oil on back portion of the left head. I'm assuming, without looking further tonight, that I either have a cracked head or a cracked block. I just turned over 1000 hours. Any of you guys had this unfortunate experience?

 

[agitch]

I'd pull the engine ducting off that side to pinpoint the leak. It could be something less serious.

 

[rswartz]

I pulled off several of the engine covers, but will need disconect the driveshaft, pull the engine and take off the rear cover to see what is going on. Anyone have an idea what this could be? I had a full crankcase of oil before I started mowing and about 2 hours later, it's practically empty. The oil seems to be coming from somewhere in the rear of the engine. Could it be a rear seal? Doesn't seem like it would go bad that fast. Any ideas are appreciated.

 

[agitch]

With that many hours it could have blown a seal. I recently had problem with a low hour M18. There was bad leak coming from the rear part of the engine and it was leaking on to the engine deck. Couldn't figure it out for the life of me. Finally I pulled the engine and put it on the work bench. There was two pin holes on the bottom of the crankcase. The holes were so small you could barely see them with the human eye. This is a low hour replacement engine and I don't have a clue what would have caused it. I JB welded the two pin holes and it doesn't leak a drop now.

 

[jlhayes]

Adrian,
I know of new engines having defective oil pans,and or blocks, caused by bad casting.
and even a speck of sand will sometimes stick making a weak spot .

Was told by a service man that one only with 20 hours had blown for this reason.

 

[rswartz]

OK. I pulled the KT 17 II from my 1711, cleaned off all the grease, but have yet to find where the oil leak is. No cracks in the crankcase or heads. The rear engine shield did have a lot of grease caked on he inside of it. I cannot tell if the rear seal is bad or not. I now have the engine sitting back on the tractor. I want to start it up to see where the oil is coming from. I have 2 questions: 1) Can I start the engine without the rectifier in place? 2) How do you replace the oil seals? Are they internal? As always, I appreciate the input and expertise you guys show on this forum.

 

[rswartz]

I thought it was a worse scenario, but it turned out to be the rear crankshaft seal that was leaking. It must have vibrated out of place in order for it to have leaked as quickly as it did. The tractor is all back together and running well, without leaking a drop of oil.

 

[jdiederichs]

Randy, If possible ask a dealer to borrow his tester for crankcase vacuum/pressure. A faulty breather will certainly force out the seal in many cases, and it may well repeat if not corrected. The tester is simple to use, it has adapters that fit into the oil fill cap and a guage that will indicate pressure (bad) or vacuum (good) IIRC the vacuum on a Magnum twin will often run in the teens, which would not allow the seal to dislodge. A pressurized crankcase will always force out a crankshaft seal. Hope this helps, and the dealer is willing to allow you to check. {If not a simple check is to use a balloon over the oil fill tube, pressure will try to inflate the balloon, vacuum will try to evacuate any air}

 

[rswartz]

Jim - Which breather are you referring to?

 

[jlhayes]

Randy you can make your own meter for testing vacuum

http://www.youtube.com/watch?v=-p8oZucZiv4

 

[jdiederichs]

The crankcase breather, they used 2 types, the "old" style was more prone to failure and should be replaced. If you take it off ask your dealer to examine it or give the service desk at Kohler a call.

 

[rswartz]

I think I found out why I lost the first oil seal to begin with. When I take off the oil fill cap, it's almost like another exhaust. You can hear the pressure coming out. I think this is more than just the crankcase breather, which I believe is tied into the carb. breather assembly through a rubber tube. Is this correct? If not, where is it?

 

[rschrader]

Long time lurker reading through some old posts and this one caught my attention.

Randy, did you ever figure out why when you pulled the oil fill cap off, it's like another exhaust? I ask because I've got an M18 in my shop doing the same thing but don't know why (it also smoked bad and was a bit low on compression, but that's another story). Anyway, just wondered if a solution was ever found for this.