on all my Toyotas, I've unscrewed the check valve, and the threads are so close to an 1/8th inch pipe thread, that you can make a hose barb fitting screw in there. Seems like the rear axle vent went through the brake line though? that might take a little ingenuity. definitely make sure the hose is rated for oil use.
-'88 pickup - Daily driver, AAL's, 285's, ARB bumper, Warn winch, all around cool rig.
-'01 cherokee - 6" Long arm'd, 285's, ARB bumper, custom roof rack, electric locked D30, auto locked 8.8, trussed-plated-fortified.
-'12 Jeep JK - 2" lift, Skid Row skidplates, OR fab bumper