I work without any payment/reimbursement for a services/business whereby I pay my own mileage and all expenses. Pro bono work. Can I deduct all the expenses & mileage?

[JulieCo]

Per IRS rules, you cannot deduct the value of your time or your services contributed, but, yes, you can deduct mileage and other expenses related to pro bono work.  

Here is information from the IRS on this issue:  IRS Pub 526, Charitable Contributions

And here is some information and links on the deductibility of volunteer work:

https://ttlc.intuit.com/replies/4797925