# Oil Leak On 6.75 HP Craftman Lawn Mower



## mingomya

I am a little green on 4 Cycle engines and hope someone can help me out.
I have a year 2000 Craftsman, 6.75 HP, 21" Multi-Cut Power Propelled Rotary Lawn Mower which has developed an oil leak and a pretty good one to boot.
This Model 944.360340 has a Tecumseh engine LEV120-361502A or Sears Model No. 143.006702.

The engine runs great, no smoke or rough idle, but is showing an oil puddle after a few minutes of running and I cannot seem to pin point where it coming from. The surface of the engine looks clean. It looks like the oil leak is coming from under the engine but I cannot understand how. The air filter is clean and not contaminated. The oil level dip stick tube, I thought might be the culprit so I siliconed it at the "O"-Ring, just in case. 
Someone said possibly the crankcase breather tube may be plugged? 
This I cannot understand or it would run rough.....correct?

I will appreciate any suggestions where to check.


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## 30yearTech

No if the oil breather tube was plugged it would not make the engine run rough, it may cause it to burn oil and leak oil out the seals. 

Where does the oil puddle??


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## mingomya

The oil is puddling on top of the mower housing but I cannot see where it's leaking from. It just seems like it's coming from under the engine.


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## pyro_maniac69

theres really only 2 things on a techumseh motor on the top to leak oil, and thats the breather, and the top oil seal, both of which are easy to replace, but the oil seal takes a little more patience


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## mingomya

Well, I am going to have another look around. 
What would you suspect, the seal or the breather? 
Do I require any special tools to get at this top Oil Seal?


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## pyro_maniac69

yes actually. but, to be sure it is coming from the breather, I don't have a diagram breakdown on my computer for Techumseh but they used a couple different styles of breathers on there lawnmower engines, one resided underneath the flywheel, and the other was a circular piece of rubber the was at the rear of the block. Clean the motor the best you can, let it dry and run it for a couple minutes shut it off, let it cool down, and then take the blower housing off and you should be able to see where the oil it coming from. If it is underneath the flywheel, it is either the oil seal, or the breather is leaking (this is if your engine is the style with the breather underneath the flywheel) now if you take your blower housing off and see a black circular piece of rubber at the back of the motor, that will be your breather.

Hopefully this isn't confusing for you


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## mingomya

OK, last night I checked it out. I found that black circular piece of rubber at the back of the engine you mentioned. The rubber tube coming from it goes to the breather which encases the air filter. What I found was the rubber house was kinked pretty bad and so I tried to straighten it out but it was to deformed to stay. So I rapped some stainless wire around the tube which kept it uniform and insured it was clean. cleaned up around the rubber seal and reinstalled everything. I then siliconed the oil dip tube to the engine again,just to prevent any oil from seeping out if the mower was tilted
I let it dry over night but have not tried starting it yet. I am at work today and will give it a whirl this evening. I hope that's all what the problem was.
I really couldn't tell at the time whether the oil leak was from that circular rubber seal which they call the breather cover.
Question, can that breather cover be pried out without it damaging anything?
I wasn't sure so I had left it. I guess if it could, I could have cleaned it up as well. I think what was happening was the air was not getting to the breather and pressure was built up inside the crankcase and releasing up through the breather seal. Would my assumption be correct?
I'll keep you informed if that bent tube was the culprit to the oil leak. THANKS :thumbsup:


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## pyro_maniac69

yes your assumption would be correct, that very well could have been your problem in the first place, keep us posted


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## mingomya

I think you may have forgotten to answer my question 

"can that breather cover be pried out without it damaging anything?"


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## pyro_maniac69

oh, I'm sorry

it might be possible, but I actually wouldn't take the chance since you have to pry it out. New ones are in the $12-$15 dollar range


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## mingomya

mingomya said:


> The rubber tube coming from it goes to the breather which encases the air filter. What I found was the rubber house was kinked pretty bad.
> 
> Just to let you all know. it was the kinked breather hose which caused the oil leak. I ran the engine last night for around 5 minutes and have not seen one drop of oil.
> 
> Special thanks to pyro_maniac69.
> 
> Cheers! :wave:


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## mingomya

*Help Again!*

Hi again, :wave:

I am back with the same problem again. What happened was the oil dip tube came loose and then it came off and I had oil blowing all over the place. What a mess! Through all this I lost the oil seal from the bottom of the tube. Anyway, I found a replacement seal, installed it and even used automotive **** to seal around the base of the tube. Yes, I also secured the tube again with the one screw, cleaned things up and let all dry overnight.
I even replaced the oil filter. 
I thought all was OK until I noticed oil leaking out around the base of the tube again. I cannot understand what’s happening here. There must be a good pressure to do this. Something’s not venting. That air line I wrapped with wire seems OK and is not kinked. You know, when the lawn mower runs, it runs well, but I cannot keep oil in it. Hope someone might know what I should do next before I give it up and go buy a new one. LOL


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## pyro_maniac69

don't goop it up, the thing with RTV is if you put it on with your fingers, there is enough oil from your hands that it will stop the RTV from sealing properly.

I would get a new one, and put it in, and call it good, no goop required.

also, make sure you put the curved part of the seal down, not up


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## mingomya

Thanks Pyro_Maniac69,

You know, I just ordered a new seal and your probably right. The "O"ring I put on had no tapper and that Goo....I wasn't sure about also.
I'll have to wait for the part and give it another try. I'll keep in touch.

Thanks


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## mingomya

Received the oil seal, replaced it and I have no leak anymore.
I see it is important to have the proper oil seal and any oil ring won't be any good in place of it.

Cheers everyone! :wave:

:thumbsup:


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## pyro_maniac69

glad to hear that you got it, and don't feel bad, that is a very common problem on tecumseh engines


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## altierior

i know this is an old thread, but wow - thanks!!! :thumbsup: 

i was having the exact some problem with my tecumseh 6.5. i was gonna take mine to sears repair. after a little searching around the web, i discovered this thread. not only did you guys save me $$, but sears had a turnaround time of like three weeks. 

i found it hard to believe that so much oil could have been spewing just from the seal at the base of the dip-tube. but a can of brakleen, a $3.19 oil-seal, and an hour later, it's all good! 

WOOHOO!!! 
:thumbsup:


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## Djz020

i wouldnt try to pry out anything either.


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## iynocerus

pyro_maniac69 said:


> don't goop it up, the thing with RTV is if you put it on with your fingers, there is enough oil from your hands that it will stop the RTV from sealing properly.
> 
> At the risk of sounding dumb, what is the RTV?


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## 30yearTech

iynocerus said:


> pyro_maniac69 said:
> 
> 
> 
> don't goop it up, the thing with RTV is if you put it on with your fingers, there is enough oil from your hands that it will stop the RTV from sealing properly.
> 
> At the risk of sounding dumb, what is the RTV?
> 
> 
> 
> *RTV Silicone* (room temperature vulcanization silicone)
Click to expand...


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