sxsilver, that seal is on the small side. I had no luck at the typical chain auto stores. There was no old school
NAPA store within biking distance either.
Worth a try, but better luck may be found at an industrial supply or bearing supply shop.
If you have a Yanmar
shop nearby you may be pleasantly surprised the price
is not outrageous for this seal, and it is a common part that should be in stock. If not shipping
will be twice the price
of the part.
If you check prices for a new pump you will most certainly be unpleasantly surprised. 500-600 clams. Shopping
around, like Depco in Sarasota
FL, May yield better results.
But there is a version of this pump that is less than 300 dollars. It has a non removable cam in the housing. I think this cam rarely needs replacing so that is a choice I would consider if the need presents itself.
To do a total rebuild
including shaft (Yanmar only) can be expensive as well.
Hopefully you just need a seal and there is no substantial groove on the shaft where the seal lip rides.
attached is from an old original Yanmar
ring binder service
manual. The seal is no. 8 in the diagram.