Oil leak

[William De]

I have a lycoming io540 that has been pushing the rubber valve cover gaskets out so I went back to the cork and they still leak. I've checked the crank case vent and it was fine. Looking for some more suggestions. It does have the airwolf air/oil separator.

 

[RotorAndWing]

I have a lycoming io540 that has been pushing the rubber valve cover gaskets out so I went back to the cork and they still leak. I've checked the crank case vent and it was fine. Looking for some more suggestions. It does have the airwolf air/oil separator.

If you over tighten the valve covers with the rubber gaskets they will leak.

Something to consider.

 

[bnt83]

If you over tighten the valve covers with the rubber gaskets they will leak.

Something to consider.

Adding to this, its pretty obvious when overtightened, the holes in the covers warp or or the flange itself does. Just lay them on a flat surface to verify.


The Reak Gasket (orange silicone) rubber gaskets are supposed to be installed BONE DRY (clean all oil off the mating surfaces) and torqued to 50 in/ibs, then run the engine to operating temp, then re-torqued, if I remember correctly.

 

[3393RP]

Adding to this, its pretty obvious when overtightened, the holes in the covers warp or or the flange itself does. Just lay them on a flat surface to verify.


The Reak Gasket (orange silicone) rubber gaskets are supposed to be installed BONE DRY (clean all oil off the mating surfaces) and torqued to 50 in/ibs, then run the engine to operating temp, then re-torqued, if I remember correctly.

Just to add a bit to your good post, once the covers are bent they must be straightened or the leak will continue.

I think most people would be surprised to find out how little effort it requires to tighten a bolt to 50 in/lbs.