Ad hoc network is a set of nodes that are able to move and can be connected in an arbitrary manner. Each node acts as a router and communicates using a multi-hop wireless links. Nodes within ad hoc networks need eficient dynamic routing protocols to facilitate communication. An Eficient routing protocol can provide significant benefits to mobile ad hoc networks, in terms of both performance and reliability. Several routing protocols exist allowing and facilitating communication between mobile nodes. One of the promising routing protocols is DSR (Dynamic Source Routing). This protocol presents some problems. The major problem in DSR is that the route cache contains some inconsistence routing information; this is due to node mobility. This problem generates longer delays for data packets. In order to reduce the delays we propose a technique based on cleaning route caches for nodes within an active route. Our approach has been implemented and tested in the well known network simulator GLOMOSIM and the simulation results show that protocol performance have been enhanced.