If you're getting a refund of excess social security paid in, then you'll see that excess amount on line 71 of the 1040, Excess Social Security and Tier 1 RRTA Tax Withheld.
To preview the 1040 form, go up into the upper margin and click on My Account, then select Tools from the dropdown box. Then click on the first item in the list of "Other Helpful Links," View Tax Summary. Then look above the summary page and click on Preview My 1040 and that will load the 2-page tax return so you can check the line number.
