Toyota HiAce 2018 Problems

Failed axle seals in Toyotas of this vintage are not unknown, but I’m not sure that they’re any more common than in any other make or model. And you’re right, replacing the seals in this model requires an awfully big hydraulic press and some pretty specific tolerances to be observed.

But the bigger question is why the seals keep failing and, more specifically, why two seals would fail simultaneously. Often, an axle seal will fail because of wear or play in the wheel bearing it helps protect. But to have two to fail together (one being a new-ish one) suggests a problem with the rear axle’s breather system. This is designed to allow pressure to escape as the axle unit heats up and internal pressures rise. If the breather isn’t allowing this to happen, the pressure can increase to the point where it will cause the seals to fail. So that’s where I’d start looking. A blocked breather fitting or crimped breather tube could easily be the cause.

It’s unlikely to be in your engine as such; rather it’s probably associated with the engine’s intake system. As it’s new take it to your Toyota dealer and have them fix it under warranty.