My mother as the only life tenant, quit deeded it to a brother who is a remainderman. Me and another brother are also remaindermen on this estate!

A quitclaim deed cannot transfer title.  The only thing it can do is note that the signer quits making a claim to ownership.  That is why it is best used with disputed easements and rights of way. The owner of a life estate (your mother, since a quitclaim deed cannot transfer title) cannot do anything which would damage the rights of the remaindermen.  (Note that the situation is different if this is not a simple life estate but a general warranty deed reserving extended life estate a/k/a Lady Bird Deed.  Your mother could revoke that at any time before her death.) On your mother's death (which terminates the life estate), your brother could file a claim against her estate for "loans" for improvements -- but would have to show tbey were not gifts.   Show the actual documents to a local real estate lawyer so that she can advise you based on the facts.