how to locate alternator leak?

[roadrider]

Hi All, during a recent oil change on my 2001 st I noticed oil on the left rear section of the lower gray cowl. Looking up from under the alternator there was oil on a round bolt/pin. Tracing bad toward the alternator I was unable to determine if it came from where the alternator connects to the rear of the engine. After reading various post there was talk about leakage from a wire harness. Where is the location of the harness. How to determine if the leak is a o-ring or seal or harness. If the leak is a seal/o-ring that appears to be a BIG repair job. Is there a successful method of repair to stop a leak without removing the alternator. Any help will be appreciated. Reply makntraxs@aol.com Ride Safe Greg

 

[kiltman]

I suggest you check your valve covers and check them for leaks as it has been known that oil leaks from there mitigate to the back of the engine. You can also check the oil site glass as sometimes the gasket wears out and it can leak and oil will make it it to the back of the engine.

 

[TerryS]

My 1990 had an oil weep from the back of the alternator. I believe the 28A alternators are oil cooled, and the wires pass though a potted section on the back end of the alternator, which was where mine was weeping.

 

[naedlaen]

The oil leak that TerryS is applies to 1995 and older ST1100 as they had the oil cooled alternator. 1996 and newer have air cooled alternators. Not that a gasket at the bottom of the alternator is not leaking, but it should not be due to the wiring harness. As kiltman suggests, clean the oil up and use a powder on the engine to try to locate the source of the leak. The valve cover is an easier fix than the deeper alternator seal, so eliminate it first.

(Knowledge gathered from reading here - I own a much older V4)

Neal