Yes all inline pumps are meant to push but like all pumps, they suck first, then push. It will be fine in your configuration. The only problem with sucking air first, before it primes with gasoling is that the air can get thinner and thinner as it's trying to get the gas. That is why it is important to make sure that your gastank cap has a working one-way vent valve. Without it, air can't get into the tank, causing vacuum lock, where nothing can get sucked out of the tank.
Tom
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Sometimes, I'm as confused as a baby in a topless bar.
My short term memory is absolutely horrible and so is my short term memory.
https://www.youtube.com/watch?v=sG16m2e4O6I