Since no free full PDF exists, here are legal alternatives:
Chabad.org offers a free interactive online siddur for Tehillat Hashem with English translation and transliteration. It is not a downloadable PDF, but you can print individual prayers: siddur tehillat hashem with english translation pdf
The Hebrew text of the Siddur Tehillat Hashem is rich with Kabbalistic intentions (kavanot). For a native Hebrew speaker, the words flow naturally, but for the majority of the Jewish diaspora, English is the vernacular. Since no free full PDF exists, here are
An English translation serves three critical purposes: Since no free full PDF exists