Rear Main Seal Leak Recoverer
The rear main seal on an engine eventually starts to leak, leaving oil spots wherever you park.
Gradually the leak gets worse and those drops become puddles.
Messy, embarrassing and a hassle having to add oil all the time, but the repair requires taking half
the car apart, so you just live with it.
What if instead of a drain hole on the plate between the engine and tranz, there was a way to pump
the oil back into the engine?
I thought of a small pan with an electric pump first, but then realized I could use engine vacuum to
suck the oil up. All it took was a jar and a few pieces of rubber hose. The proof of concept device
was plastic - it worked, but the vacuum collapsed it when it got hot, so I replaced it with a glass jar.
I used it for about 6 months. It eliminated the puddle, but the messy hassle of emptying the jar into
the engine got old fast, so I came up with an automatic drain version.
It works well, but needs a vacuum shut off float valve for when it fills up. A year after I installed
it the leak got so bad that the RMSLR woud fill up in less than 10 minutes so the oil would get sucked
into the intake, making a huge cloud.
Fortunately, I found a way to change the rear main seal without taking the engine or transmission out.
But, because the engine bearings are worn, it still leaks, so I left the RMSLR on. The engine has
175,000 (or maybe 275,000!) miles on it, so it's likely something will break soon. I'm hoping it will
hold out till I have the money to convert the car to electric.