Technical Oil out of vacuum wiper motor

Anybody ever have a problem with oil dripping out of a vacuum wiper motor. Wipers still work well but oil is somehow dripping out of the unit. Its tucked up behind the dash so I haven't yet removed it to investigate. Since the only connection is a vacuum line to the intake I'm having trouble thinking where excess oil can be coming from. Don't think it's important but it's in my 50 Chev car with a 261 six.
John

 

Very strange, unless someone over oiled the vacuum motor.

 

Let me guess. Does the '50 still have a dual diaphragm fuel pump ? If so, the vacuum unit is ruptured & sucking oil out of the crankcase … I've seen some that ate a quart every 100 miles.

 

No on the dual diaphragm pump. Just using the simple pump.

 

No duel diaphragm , then I suspect tons of blow by vapors settling out in the wiper vacuum tubing

 

A common fix for these was to squirt some ATF or oil in there, which softened up the leather seal. Maybe it's still dripping out from a previous "treatment". Do you have a PCV valve connected to the manifold vacuum ? If so, it may be sucking crankcase fumes into the wiper, and then it drips out. One of those catch-cans the "go-fast" boys use should fix that.

 

I do have a PCV connected to a modified draft tube. Since intake is always under vacuum seems strange oil vapors would find their way to the wiper motor. Wiper vacuum connection is to top of intake. Maybe with engine off vapors rise back to wiper? Seems a long shot but haven't come up with anything better.

 

What I would do is to run a clear plastic pipe between the manifold and the wiper motor to see if the is any oil build up in the pipe.Then you can see if vapors do rise up with the engine off after running.

 

Good idea brading. I'll give it a try.

 

Kindly let us all know what you find.

 

Is there really that much oil in engine vapors after the engine is shut off?

Highly likely that someone got liberal with the application of lubrication.

 

Never got around to trying clear tubing but I did pull the vacuum line off the intake and swabbed it out with a q-tip. Didn't show any residue to speak off. Think I'm gonna have to crawl under the dash and pull it down to inspect but it hasn't made it to the top of my to do list yet. Thanks to all that gave ideas.