Legal problem

Hello, I have a problem with my used car dealer. I recently bought a Xantia Activa in a Renault car dealership (Ez 3/98, 77TKM). 2 weeks after the purchase it was found in a Citroen contract workshop that the front AFS cylinder is leaking. Since the error occurred so soon after the purchase I assume that this is a warranty case and have asked the dealer to take over the repair costs of 460 €. The dealer sees the case but as a guarantee case and according to the warranty conditions only 50% of the costs will take over. He justified his opinion by the fact that I have confirmed under witnesses that the car at the time of purchase I.O. practically bought as seen. I already called the lawyer and she meant the statement from the dealer is nonsense and I am right. Unfortunately I have no legal protection insurance and since the dispute value “only” 230€ the lawyer thinks that a lawsuit would not pay. Is anyone like me still right or what else can I do?