An apparatus for coupling two hydraulic transmission lines to one another is disclosed. The apparatus comprises a first coupling member and a second coupling member. The first coupling member comprises a body having first and second passages. The first passage extends from the connection to the first line to the second passage. A plug is movably positioned in the first passage for selectively opening and closing the first passage between the first line and the second passage. A first and second passage similarly extends through the second coupling member, and a plug is movably positioned in the first passage for selectively opening and closing the first passage between the second line and the second passage. The first and second coupling members are selectively joinable via a sleeve extending between the second passages thereof.