diesel fuel in engine oil test

Is there an easy way to tell if fuel is leaking in to the crank case? I just put a rebuilt injection pump on a tractor and want to make sure the umbrella seals are holding. I am sending this tractor over to another farm for a few weeks and will not be able to keep an eye on it after it leaves the shop.

Thanks

If its gettign higher on the stick when you check it. check it weekly or more often if you drive it daily a fair amount of miles. you will see it go up. i have seen LB7's wut fuel/oil coming out of the valve cover breathers and onto the ground and it still ran fine and after the injectors were replaced the engine was fine. drained 5 gallons out of the engine