· Premium Member
I had to replace both top cylinders in one of my 66 Convertibles last year. I know the cylinders were replaced about 20 years ago by a previous owner and the car sat for at least 15 years before I acquired it. There could be any number of factors that could cause the cylinders to leak. Mine failed more than likely due to non-use and the seals became dry and brittle. Any corrosion on the ram, which is exposed when the top is up will accelerate the deterioration of the seal when the top is operated. Also, the previous owner could have used cheap imports, so that could come into play. Obviously you don't want to cause unnecessary stress my holding the switch too long when the top is fully up or down. Due to tolerances and differences, it's best to replace the rams in pair. Type F ATF fluid is recommended.