Is the leak at the primer pump? You have to isolate where the leak is. If the primer pump is the old style that unscrews to pump you're leak is most probably there. That part can be replaced with a 24 mm crows foot. It will take a 17 mm crows foot to install the new part. 000 090 88 50 is the new part number. $38 retail price. It can be found for less just shop around. John