Originally Posted by Ernie45
I just put it in my 98 Ford Ranger 4.0 engine 106 K miles with leaky valve covers... l
Leaky valve covers use gaskets, not elastomeric seals.
Originally Posted by Molakule
When discussing seals such as in engines, transmissions, and other driveline components, the context is that of using flexible, elastomeric materials to keep fluids contained within the mechanical system that have rotating components exiting the system, such as protruding rotating shafts.
For a gasket, the context is that of using a material (such as silicone or cork or composite), or some other material to keep fluids contained in and around stationary objects, such as the valve cover gasket on an engine or the pan gasket on an automatic transmission.
Both seals and gaskets "prevent" loss of fluids...
Conditioning seals refers to the following actions:
1) Increasing seal pliability due to Seal elastomer molecular replacement
2) Seal cleaning,
Today's synthetic formulations have pretty much solved the seal "shrink-swell" problem.
Stop leak fluids have little effect on Gaskets, so if you have a leak to the outside, it is usually due to a Gasket, not a Seal.
Now on older vehicles or vehicles with rear wheel drives, the most common fluid leak occurs because of a worn tailshaft seal, and is mostly seen when parking on an upslope where the rear of the vehicle is below the front.
On front wheel drive vehicles, the most common fluid leak is due to the pan gasket, in my experience.