Hey guys, having a problematic 727 that keeps leaking fluid from the dipstick o-ring. I have tried several sizes with no luck.

My main question is sizing, does anyone know what spec is for id/od/thickness?

My other thought is material, i bought a bunch of different sizes from farm and fleet's o ring section, could the material not be compatible with the fluid, causing the leak? Last one that went in was a TIGHT fit, i thought i was good to go and it did not leak in the garage when test run, but first drive out on the road, stopped for gas, had a large puddle underneath.

Any help would be appreciated. John