I want to second what everyone else is saying: definitely call ahead. I also suggest confirming by email so that you have a written OK with that chapter's president. You don't just "crash" another chapter. As a member, it is important to show respect for each other. Ditto on what everybody has already said. I'm surprized that you needed to ask.
When I was in undergrad, I came home to my chapter house late one Sunday night (after 11pm) from studying at the library to find my brother sitting in the lobby. He was on his way back from a visit home and was going to his campus and his fraternity house but stopped by to visit me on the way. We had a short talk, and he asked if I knew any place where he could crash for the night. No problem. I immediately called the chapter president of the fraternity where I was a little sister at and asked him if my brother could crash on one of the couches for the night. Keep in mind that this was all before cell phones or none of this would have been an issue.
I told my brother where the house was, he witnessed my calling the president & heard the entire conversation. I did hear from 2 brothers who asked me about him, though. They said that yes, it was noticed that there was a strange guy who no one knew sleeping on one of their couches. Then some one had said that it was my brother so that was OK.
While I don't advocate doing this, there are circumstances that arise. Now, I would not even stop by to visit one of our chapters without calling first. I did visit Northwestern's chapter house once while I was in college without calling beforehand, but this was the one & only time. Have a great visit!