Old School Ghoul

Old School Ghoul is an unmarked quest in Fallout: New Vegas.

Activating the quest
Raul Tejada, the ghoul found captive at Black Mountain, must be the player's active companion when the player initiates dialogue with Ranger Andy in Novac, Corporal Sterling in Camp McCarran (or Camp Forlorn Hope) and Loyal at Nellis Air Force Base. There is no set order to which non-player character you approach first, but all three must be spoken to until their dialogue trees have been exhausted. At the end of each interaction, Raul will start a conversation with the player that revolves around both his observation of the characters and anecdotes about his history.

Detailed walkthrough
Talk to Ranger Andy with Raul present. The key topics are what he does in Novac ("what do you do here?"), and what happened to his leg ("Did something happen to your leg?" or "What happened?"). Raul must hear these answers, so you may need to repeat dialog you've already had with Andy. Learning the takedown move is NOT necessary, but doesn't hurt. After this, leave the building and wait a few seconds for Raul to run up to you and talk. Raul will initiate a dialogue concerning the player's opinion of Ranger Andy's place as a crippled, older man in a harsh world. The choices made by the player will influence which way Raul decides to proceed at the end of the quest, ultimately affecting the player's reward. The player has an opportunity to hear part of Raul's story but may skip this portion of the dialogue at no penalty.

The player must then travel to either Camp McCarran or Camp Forlorn Hope depending on the completion status of the quest Three-Card Bounty. The player must speak with Corporal Sterling, a 1st Recon NCR sniper stationed with the rest of his squad at Camp McCarran, defending the region against fiends. If the bounties have all already been turned in to Major Dhatri during the quest "Three-Card Bounty", his squad will have been reassigned to Camp Forlorn Hope. After initiating and ending conversation with Sterling, Raul will initiate a dialogue similar to the one held after learning the takedown move from Ranger Andy.

Upon completion of the first conversation, the player must travel to Nellis Air Force Base and initiate a similar conversation with Loyal. He can typically be found in either his own house or the hangar housing the bomber. After ending the conversation, Raul will initiate a final conversation wherein he ties the stories of the three men the player has met thus far to his own story. He will decide to either return to his gun slinging vaquero ways or relegate himself to a quieter life of machine (and armament) maintenance. The decision at which he will arrive is influenced entirely by the player's dialogue responses during the progression of this quest. However, the player has the opportunity to sway him to the other alternative with a speech skill of 66.

After completing the final dialogue, Raul will receive an upgraded perk. Old Vaquero if the player convinced him to return to the ways of his gun slinging past increasing his fire rate with revolvers and lever-action rifles by 33%, or Full Maintenance if the player urged him to contribute in other ways increasing the reduction in weapon degradation that he provides from 50% to 75%. If Raul upgrades to the Old Vaquero perk, he continues to provide the Regular Maintenance perk. His outfit will also change to the Vaquero outfit or the Armored Petró-Chico outfit appropriately.

Bugs

 * If you have already learned the Ranger Takedown technique from Ranger Andy in Novac without Raul present, you can correct this by using the console and typing the following exactly:
 * . This must be done in an indoor area. Transition to an outdoor area and Raul should initiate conversation. If that console command doesn't do the trick, try, then talk to Raul and pick his new dialogue option about Ranger Andy.
 * Worth a try if nothing else is working with the Ranger Andy/Raul interaction. If you have already completed all dialogue options with Ranger Andy, open the console and target Ranger Andy, or enter . You can reset all his dialogue options by entering . (This will also reset any other NPC dialogue, so be careful!) Once you've done this, close the console and speak to Ranger Andy. He will now talk to you as if you'd never met, allowing you to trigger the Raul interaction, once you walk outside, if he is in your party.
 * Also, if you are not able to access Raul's story after speaking with Corporal Sterling, you can input a similar console command: . Again, if the previous console command doesn't help you can try and select the dialogue line about Sterling.
 * And, lastly, if Raul is making problems about not giving you the dialogue after meeting Loyal, you can of course use the console to fix that as well: will open the "spontaneous" dialogue,  will give you the ability to talk to him — "You wanted to say something about Loyal…".
 * For some reason Ranger Andy will not engage in dialog at all even though the HUD will zoom in to make it seem you will be able to but will then automatically zoom back out making it impossible to talk to Ranger Andy.
 * You will be unable to talk with Corporal Sterling. He only replies with a generic line without opening dialogue if he is stationed at Camp Forlorn Hope. This may be fixed by spawning Driver Nephi and letting the rangers kill him:.
 * For yet unknown reasons it is possible that talking to Ranger Andy in Novac does not trigger Raul to speak to the player. Making it impossible to start the quest even if you have not learned Ranger Takedown prior to having Raul with you. Note: this bug may be corrected on the PC version by using console commands. See the section marked "Quick Walkthrough" for details.
 * After Patch 1.02 it is now possible to initiate the quest by talking to Ranger Andy after learning the Ranger Takedown Move, though you must still have Raul as a companion at the time.
 * Raul doesn't start the final conversation after talked to all 3 Characters and receiving all 3 regarding dialogues from Raul. To avoid this, the player must not talk to Loyal after completing the quest Volare!, when he thank you for making his dreams a reality; can't initiate the side-quest I Don't Hurt Anymore AND talk to Corporal Sterling; can't talk to Ranger Andy prior to having Raul as a companion. After having Raul as a companion you can talk with Loyal, Corporal Sterling and Ranger Andy in whatever order you want, as long this conditions are fulfilled. (This was tested in three different playthroughs.) Sometimes if the final conversation does not occur it can help to decline Raul of his conversation after speaking to the last person, by saying "Not now Raul", and then speak to him about it (on xbox with Corporal Sterling last).
 * PC Users: If Raul won't initiate the final conversation open the console, click on Raul and try the following commands: followed by  and finally
 * Note that it's not case sensitive, and you MUST click on Raul before entering the "startconversion" command.
 * There is a case that if you fast-travel right after exiting Ranger Andy's Bungalow, Raul's dialogue option will not be triggered. Just wait a minute to see if you get the trigger. Note: This may have been fixed in a patch, as if you "Talk To" Raul, you can scroll down & ask him what he wanted to say after visiting Ranger Andy's, but didn't have the chance to.
 * A known bug occurs with Loyal where he sometimes disappears from the game. If you complete Volare! before recruiting Raul, Loyal may no longer be present at Nellis, making the quest impossible to finish.
 * A known bug occurs with Corporal Sterling where he sometimes disappears from the game. After complete the quest Three-Card Bounty Corporal Sterling and 1st Recon move to Camp Forlon Hope, they all for some reason disappears, making the quest impossible to finish.