Kim Kardashian -- I'm Locking Up My Crap While I'm in Hiding

Kim Kardashian's private belongings are currently locked up in a VAULT while she hides away with her baby -- and they'll stay there ... at least until she moves into her new mansion, TMZ has learned.

A moving truck was photographed outside Kim's old Beverly Hills home on Tuesday -- while Kim was still in the hospital after giving birth -- and we're told it was there to pick up all her personal effects in order to be moved to the new $11 million mansion she bought with Kanye in Bel Air.

Unfortunately, the new house isn't ready yet -- and the old one is about to be renovated -- so we're told Kim had to place her stuff in storage vaults ... for the time being.

We're told Kim's stuff is occupying a total of three vaults -- and each vault only costs $50/month to rent ... so it's not a huge investment.

Kim is currently out of the hospital staying at a mystery location with the baby.