In World in conflict repair vehicles are like the medics of the battlefield though aren't that armored and have little or no armament. The repair vehicles in this game are either the troop transport or the repair tank. The troop transport repair tank. They Repair all things metal including helicopters

Troop Transport	Repair tank
The troop transport is primarily a fast transport vehicle but features a 50.cal machine gun and can repair other vehicles and fortifications. this unit can also be air dropped as a tactical aid this is effective on isolated areas of the map such as islands where your repair vehicle[s] cant travel there on land. The troop transport can engage enemies with Armor Piecing Bullets.	The Repair tank has medium armor and can perform repairs on vehicles faster than the troop transport. The Repair tank's offensive ability emergency repairs can instantly give the damaged vehicle 1/3-1/2 heath instantly. The repair tank's defensive ability can perform repairs on it's own vehicle.
M1025 HMMWV	A88A1 ARV
Cost Infantry: 550 Air: 850 Armor: 700 Support: 550	Cost Infantry: - Air: - Armor: - Support: 900

To repair a vehicle it is just the same as attacking but on a friendly unit