No rush I guess, but then again there's really no need to search around to order it. They don't cost much, for some reason I think I paid like $30 or $40 but that was probably on a commercial account. Thing is, if the slave isn't totally doing it's job, your clutch suffers. it won't totally separate the motor from the trans, so if that happens you'll effectively be burning up the clutch everytime you stop and have the Jeep in gear. But, so long as you do it relatively soon, it's probably not a huge deal. Try pumping it when you're at a stop, with some luck that'll help it limp along a few days while you get the stuff.
