Oil Leak Near Oil Pressure Sender

Oil Leak Near Oil Pressure Sender

It took me about two years to finally put a small oil leak to rest. It's now been dry for months, so I can finally claim victory and share the news of how I fixed it. The telltale signs of the leak were ever-present drops of oil on the oil sender wires, and a grimy coating on the belly pan. I replaced the oil sender - no change. I unscrewed the oil sender housing, replaced the crush ring, reinstalled the housing and torqued to proper specs - no change. As part of my motor mount replacement, I replaced the oil pan gasket with a new one, coating both sides of the gasket with Yamabond 4 sealant. That worked great as far as the oil pan gasket was concerned, but I still had that pesky leak in the vicinity of the oil pressure sender!

In a rare, brilliant flash of inspiration here's what I decided to do next. I removed the oil pressure sender and its housing and cleaned the threads thoroughly to remove all oil. I then coated the threads with a small, but even amount of the magic Yamabond 4 sealant. This was done for the threads on both the oil pressure sender and the housing. I let the Yamabond cure for 30 minutes or so and then reassembled everything. I reused my old crush ring, but, to be thorough, you might want to use a new one.

I left my belly pans off for a couple of weeks and, much to my amazement, the oil pressure sender stayed dry! So, I reinstalled the belly pans and took them back off a couple of months later while performing other service. Still dry! No grime on the belly pan at all. So, there you have it. Ride on down to your nearest Yamaha bike shop and pick up a tube of YB4 and give it a try.

Oh, one more thing. As I recall, it can be a little bit difficult (OK, impossible) to get a wench onto the oil pressure sender unless the alternator has been dropped down out of the way. Maybe you can get in there with the appropriate size "stubby" wrench - I don't know, because I didn't have one. I recall wrapping the pressure sender with something to protect it (electrical tape) and then using a pair of Vice Grip pliers to get the thing off and back on. (I see you cringing, and I don't blame you! Hey, it worked for me!) Once the sender was off, removing the housing was pretty easy. It just required a 1/2-inch drive socket wrench. Be careful as you let the housing down, there is a spring that you'll need to pay attention to for proper reinstallation, as well as the crush ring. Also, you will need to catch some oil with a small catch pan, but really not very much comes out.

+Greg Nichols
Alexandria, Virginia
'87 928S4, 5-speed, Venice Blue Metallic

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