Looking for 2007 CAT 303c cr service manual in PDF format
No such thing unfortunately, at least not a genuine Cat one. The only alternatives are paper or on-line. A CD-ROM with a pdf Parts Manual is available.
ok, thanks. Is there a free online alternative?
With Cat involved - you're joking, right..? A used paper Service Manual would run you about $400-ish. Compared to what you paid for the machine that's relatively cheap. Alternatively try this web site. I have never used these manuals myself, maybe someone else has experience of them ........ https://servicemanualpro.com/