The episode "And Then There Were Two" started out with Rico still not trusting T'Phai. By the end, they work together and save the other squad members. The best part comes after T'Phai's suit is damaged He tries give Rico a good farewell and Final Speech. But Rico ain't having none of that! So he goes from trooper to trooper, looking for somebody among them who can help!
And before that, in "No Substitute", T'Phai spends the majority of the episode being rejected and ostracized by the Roughnecks save for an empathetic Higgins (likely because he's been in that position before). When the T'Phai distracts the Ripplers from detecting the squad, Higgins is the first to rappel down to save him.
A Flash Back in one episode shows Rico going through Boot Camp, with Drill Sergeant Nasty Zim badgering him the whole way, daring him to quit if he turns out not to be tough enough to get through it. During Rico's final test, he is too exhausted to make it over an obstacle and finally gives up. Zim refuses to accept that, and helps Rico through the final part.