For a leak of that magnitude I'd suspect the spring popped off or the seal got bent or not in square but you did everything spot on. Probably have to R&R them & I'd pack the rear of the seal full with vaseline or grease to keep the spring in place and I use a driver with an OD as large as will fit so it bears on the outermost OD of the seal and drive it in with as few strokes with a BFH as I can so a good whack each time EDIT get the seal barely started but firmly in there square then as recommended whack it good till it's seated and if it starts to get cocked sideways use a round flat piece of stock with a drift and move the drift to the high side to knock that side in further to even it up then switch back to the BFH/centered driver