CA Civ Proc Code Section 996.360

If a surety cancels or withdraws from a bond:

(a)

The bond remains in full force and effect for all liabilities incurred before, and for acts, omissions, or causes existing or which arose before, the cancellation or withdrawal. Legal proceedings may be had therefor in all respects as though there had been no cancellation or withdrawal.

(b)

The surety is not liable for any act, default, or misconduct of the principal or other breach of the condition of the bond that occurs after, or for any liabilities on the bond that arise after, the cancellation or withdrawal.

(c)

The cancellation or withdrawal does not affect the bond as to the remaining sureties, or alter or change their liability in any respect.