I just saw this on an early Valiant/Barracuda forum. It may help you with this certain leak.
JUNE 2025 After several attempts and failures to get the 64 shift cable O ring to stop leaking (tried same size as stock, different sizes and materials) with no success I found this odd size metric O ring at the local Ace Hardware. Lubed it with some O ring grease, it was a tight fit but it worked. It has been bone dry for over a month while my other attempts only lasted a few days to a week. Could be a winner! "UPDATE ON THIS POST" I TRIED SEVERAL DIFFERENT SIZES AND COMPOUNDS OF O RINGS WITH THE BEST ONE LEAKING IN ONE WEEK TO THE WORSE IN 30 MINUTES. THIS HILLMAN METRIC 12X18X3MM I GOT A ACE HARDWARE AND INSTALLED WITH O RING LUBE HAS MADE IT OVER 8 MONTHS AND IS BONE DRY.
JUNE 2025 After several attempts and failures to get the 64 shift cable O ring to stop leaking (tried same size as stock, different sizes and materials) with no success I found this odd size metric O ring at the local Ace Hardware. Lubed it with some O ring grease, it was a tight fit but it worked. It has been bone dry for over a month while my other attempts only lasted a few days to a week. Could be a winner! "UPDATE ON THIS POST" I TRIED SEVERAL DIFFERENT SIZES AND COMPOUNDS OF O RINGS WITH THE BEST ONE LEAKING IN ONE WEEK TO THE WORSE IN 30 MINUTES. THIS HILLMAN METRIC 12X18X3MM I GOT A ACE HARDWARE AND INSTALLED WITH O RING LUBE HAS MADE IT OVER 8 MONTHS AND IS BONE DRY.
I didn't retype the original post. Copy and paste.














