What if a 301 redirect is removed?

[Bull135]

Suppose the following scenarios after a 301 redirects from source URL to targent URL is removed.

1. If source URL raises a 404 error, will target URL retained the link juice previously passed from source URL?

2. If source URL starts to show different content than what is showing on target URL, will the previously passed link juice be credited back to the source URL?

[MichaelC-15022]

#1: no.  Once both pages have been recrawled, and maybe a month has gone by to "settle" out the link juice, they'll be independent pages again.

Now, having said that, it's very possible that once you've 301'd a URL, it's going to be very low on the crawl priority, as the 301 TOLD Google that the redirect was permanent.  But eventually it'll recrawl it.  You can force it in WMT with a Fetch as Googlebot + Submit URL.

When Google appears to have the memory of an elephant regarding links, the circumstances are usually something like this:

1. Google crawls the URL and gets Good Stuff.
2. Then, the URL goes away (404s or 500s).
3. Google is hoping to see that lovely lost URL come back, and even if it no longer finds links to that URL (internal or external), it will continue to try to refetch that for quite some time (months, it seems).  Ditto Bingbot, btw.
4. In the absence of new info (the page simply is missing or broken), Google will keep its cache of what was on the page, show it in the SERPs, and retain link metrics from it to other pages....for a LONG time.

I've seen no evidence at all that Google has a "memory" for past link juice and transfers that juice the way you've described.  However, it seems clear that the folks at Google DO have the ability to look at link history manually, through their tools....for instance, to evaluate changes in backlinks for penalty reconsideration.