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ThatRickGuy

450 going through a lot of oil

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Hey Folks,

 Picked up a Farmall 450 gas this summer for taking care of the hay field. The previous had paid for a "valve job" on it~ 3 years ago, but I don't have details on exactly what they did. I'm seeing ~105-110 psi compression from each cylinder. Spark plugs are oily but not to the point of fouling out. It has a bit of a stumble at idle and light load. But most concerning, I'm going through a gallon of oil for every 10 gallons of gas. Exhaust looks pretty clean, a little smoke on startup, but cleans up by the time you close the choke. It looks like the rear main seal is leaking a little, but no wheres near that kind of volume. When running, the crank breather tube smokes like a son of a gun. 

 I'm thinking the piston rings are leaking enough to cause excess pressure in the crank case, but I'm a shade tree mechanic at best and would love some ideas from folks with more experience before I dump another grand into a rebuild kit for something like a clogged vent line. 

Thanks,

-Rick

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Valve job with old rings will make a smoker just about every time. The cure is new rings.

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Glad to know I wasn't far off. Since I have to pull the pistons to replace rings, I'm thinking rod bearings would be good to to at the same time. I assume the mains would require splitting the tractor to get the crank out? Anything else I should look to do while the head and pan is off? 

Thanks,

-Rick

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As long as I'm pulling the pistons, is it worth getting new high compression pistons? I've only seen a couple of options (fire crater from agkits and unknown from Denny's carb shop). 

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Should be able to roll new mains in without dropping the crank out.Only one I've seen that you can't, was an 1135 Massey, front and rear caps had bolts coming through from the outside to hold the seal carriers. Typical British engineering! Perkins engine, the first and the last I ever owned!

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I just had my C281 apart and saw no reason you couldn't roll in main from underneath once the pan and that rear pan plate thingy is removed.  Might get a little tight at the back, against the bell housing plate, however.

 

Chris B.

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On 7/17/2020 at 10:17 AM, cbfarmall said:

I just had my C281 apart and saw no reason you couldn't roll in main from underneath once the pan and that rear pan plate thingy is removed.  Might get a little tight at the back, against the bell housing plate, however.

 

Chris B.

I have to correct this after some thinking.  The plate for the oil pan bolts is over the cap and that plate bolts to the seal retainer which is impossible to access without a split.

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