First, Lowes carry a Hilman rubber bung (3/4 x 9/16 x 1 long) in their hardware aisle for about a buck that fits well into the back up light switch hole to minimize fluid loss (i.e., avoid Swepco face). I got two, & 1/4" drilled halfway through into the smaller end of one (to provide clearance for a working pin), and thru drilled the other 5/32" to use to verify & measure pin movement without fluid loss - both worked great. I lost 3-4 oz total (caught in a plastic bowl) over half-a-dozen on/offs.
Also a magnetic pick up with a bendy aluminum shaft works a treat to extract the pin - but you can't avoid at least some oil dribbling out, especially if like me you repeatedly dropped the slippery parts while trying to install/remove them.
Continuing the saga of no back-up lights/too-short pin after 915 rebuild:
Using the same 5/32" Bosch drill bit shank as suggested by schmidter91, but first with the whole non-fluked portion in the drilled bung until a new length was determined. Then a bunch of measurements on the switch operation with a dial gauge, and testing for pin movement (there was!) & measured that, there's about a 10mm stroke from the reverse full out position if you push the pin all the way back in when in neutral. Of course the only important one re switch operation is the out/reverse-selected position. My original pin length was 52.28mm. It was WAY down in the hole with reverse selected - it looked like it would barely reach the switch body.
If anyone wants all the numbers & info I'll post a drawing, but the upshot was that, WITHOUT ANY WASHER, to put the pin tip in the middle of the switch ON stroke zone, a new pin needed to be 5.7mm longer than the original; my washer was 1.42mm, so added that on too, taking off an arbitrary 0.1mm to allow for any tip wear to move the pin end closer the middle of the ON range... so new pin length was 52.28 + 5.7 + 1.42 - 0.1 = 59.30mm, in effect exactly 7mm longer than the original, and suspiciously, the same new length as schmidter91 had also determined... strong implication that we are dealing with the same issue, thus it seems possible this will be something more folks will be encountering...
My shop was going to charge me for a new switch, but this wouldn't have helped at all. Just called my shop with this story and it rang a bell... revised internal parts suspected... something that's happened since 2003 or so at a guess, then, as this didn't happen with my last rebuild.
Figuring the original pin's stepped-down switch-end diameter was to allow for any off-center issues & prevent it from jamming, I compromised & just tapered (drill press, files & 400 grit) maybe 8mm switch end of the pin to make sure it could "find" the switch hole in case it was a little eccentric, and if it pulls out clear of the switch - the stroke length would allow for this even if there is little reason for it to do so, but it might get a bit magnetized, or the oil will stick it to whatever pushes the pin, who knows.
Meanwhile, it's sooooo nice to have my halogen back-ups working again.
Thanks for blazing the trail here, schmidter91 - still be nice to know what internal part is the culprit though.
