How Not To Install an Oil Level Viewing Glass
I've had a new oil level indicator sight glass sitting on the shelf for 10 months but I always forget to install it at oil changes. The sight glass on the bike is nearly impossible to see through. I realized last night that if the bike was on the side stand the glass can be changed without draining the oil. Doh!
I decided on the screw method (not the soldering iron method) to remove the old glass (which is actually plastic) and the old sight glass came out without much of a fight. A screwdriver, sheetrock screw, and some needle-nose pliers did the trick.
I cleaned the aluminum mounting surface and the rubber ring around the glass with an oily rag, and proceeded to push the new sight glass into place. Then it occurred to me that both surfaces should probably be clean and mostly free from oil residue so I wiped them down with a clean cloth.
It took a few tries to get the new sight glass in place evenly with my fingers, about halfway installed. The largest socket I have is a 1-1/8 and that, along with a rubber mallet finished the job, but I had to hit the socket a little harder than I though necessary to seat the rubber seal. I fired up the bike, let it get hot enough for the fan to kick in for a while, and it all looked great.
Today I started thinking that maybe the mounting surface and rubber seal should be ultra-dry and clean, and a little internet reading seemed to substantiate that. I also stumbled onto some threads where different rider's sight glasses had fallen out while the bike was in use, and some had reported seeing the glass get "cloudy" just before. I imagined how tragic it would be to have it pop out on the highway at 70mph, with oil gushing under the rear wheel.
So this afternoon I fired up the bike again, let it get a little warm, and noticed an odd fogging in the sight glass. I didn't look like frothy oil, but more like stationary vertical cloud streaks on the inside glass surface with clean brown oil behind them. Had I broken the glass under the rubber seal when hammering it in? Was it not seated enough? I'm not taking any chances.
The new level indicator is actually made of glass so the soldering iron method will not work to remove it, and the screw method has the potential to leave shards of glass in the oil pan. The only way I could figure to remove it safely was to drain the oil, pull the oil filter, and tap the viewing glass from inside the oil pan with a long screwdriver. That worked.
Tomorrow I'll pickup a new sight glass / level indicator (and a spare) at the dealer and finish the job properly. I'll stop by the hardware store and get a short piece of 1.25" PVC or a wood dowel (a better fit than my 1-1/8 socket) to help tap it into place too. And I'll thoroughly clean all surfaces.
Moral of the story: Measure twice, cut once. Do your research first.