March 1, 2021 at 8:17 pm #232652
I have a Caille Pennant that once I disassembled found that the piston rings were not in the greatest shape and one in particular is missing the pin that holds the ring in place. The question I have is can a pin be re-drilled and put back in another spot close by the original. If so I would like to hear what was found to be the best way to accomplish this.
RICHARD A. WHITE
US Member - 2 Years
Topics: 137March 2, 2021 at 5:52 am #232663
Why not put another pin in the same spot?
Canada Member - 2 Years
Topics: 25March 2, 2021 at 6:04 am #232664
You certainly can. It is a relatively simple operation to undertake. But before you drill anything, check to see if the pin was located inside a cast boss that is provided for the reason of giving a place to put the pin that has enough material around it to support it properly. You may find that if the pin is broken off flush with the surrounding surface, you can push the broken piece of pin through the bore and press another one in to take its place. If I recall correctly, the Pennant used cast iron pistons, but my memory is fuzzy on that so you’ll have to correct me if I’m wrong.
Either way, if the hole is there but the old pin isn’t, you will either have to re-use that hole or plug it.
TO drill another hole is not a hard thing to do with the proper tools. I’d suggest using a V-block large enough to clamp the piston into, or failing that, a proper mill or drill-press vice. Whichever way you hold it, the important thing is to verify that you drill a hole exactly perpendicular (in other words, at 90 degrees) to the centreline of the piston, as you don’t want to install the pin so it’s seated at an angle. Don’t just clamp the piston into a vise and go at it with a cordless drill.
I recommend drilling with a 5/64″ drill bit then reaming the hole to 3/32 (0.093″) and installing a piece of 3/32 brass rod into the fresh hole you just made. Use some Loctite on the pin to help it stay put.
Hope this helps.
PM T2March 2, 2021 at 7:46 am #232665
Thanks for the information. I will look at it tonight to see if it is possible to push through before drilling. Right now it is sitting just slightly above flush which made me feel that trying to drill it out would only cause the bit to walk sideways on me and create a bigger problem.
PaulMarch 2, 2021 at 9:28 am #232674
I feel a little dumb on this one. I never looked inside the piston thinking that the pins were bottomed out in the side of the piston. Once I looked in the piston I could see all three locator pins sticking inside the piston by about a 1/2″. I am going to try and press it though first.
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