my 1984 jeep came with a radiator recovery tank, but it was gone when I got the jeep along with many other parts.
I got a replacement tank from Quadratec jeep parts: good place to shop for parts
part # 51216.03 this tank is made for my model, but it might fit yours for $21.99
after review 3 places said your cap should be a 16 psi cap.
but, you are going to have to check, there may be difference in a system that came with a recovery tank and a system that did not come with a recovery tank.
that psi cap may not let the coolant flow to the tank????????????????
my 1984 came with a recovery tank, might check with your parts dealer and see what psi a 1984 model came with, as I do not remember the cap psi of my jeep.
my truck is one number, jeep another and old tractor is another.
not a number I keep in the back of my mine.
good thing to install if you have small children and pets roaming around where you part the old jeep
as my old jeep would puke up some green coolant from time to time before the recovery tank was installed.
do not know why, but I understand kids and pets love the sweet taste of the coolant
if so they can make med taste like crap, why can they not make coolant taste like crap.