Hello fellow TR enthusiasts.
I wrote recently detailing the seizing of my pistons on their con rod/pin
assemblies after being cleaned with everyday parts cleaning solvent. I
described a crystalized residue which had the appearance of dryed pine sap
which was all around the inside of the piston skirts, and had plugged many
of the oil ways leading up to the wrist pins.
Firstly, thanks to all who posted WARNINGS regarding my "not so" bright
idea to have the assemblies hot tanked. I'm still not sure what I was
thinking. Of course the aluminium pistons would melt.
Secondly, I have since completely disassembled all pistons from their con
rods. This process required an industial strength penetrating oil, and a
good deal of elbow grease. What I discovered when all was apart, was that
despite the distasteful appearance of the crystalized goop...what had in
fact seized the pistons on their pins was nothing more than good old
fashioned RUST. It seems that the cleaning solvent had gotten in and
removed much of the lubricant from between the piston pin and the con rod
small end bearing. Once the remaining solvent evaporated, it left bare
metal which quickly corroded. The clearance tolerances for the piston pins
is very small, so it didn't take much rust and "voila" seized piston/con
rod assemblies. I'm happy to report that after a light cleaning of all
parts with 440 grit emery cloth and re-lubricating everything prior to
reassembly, the piston assemblies are now ready to go back into their
bores.
Thanks to all who took the time to respond.
Paul Lacroix
1973 TR6
Ottawa,Canada
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