for sure cap, not one lasts 30 years.
its bottom gasket fails and cracks, all do. old.
the rad 2 tanks love to fail way way before this.
the system must hold 14psi (or 12) PSI pressure if not fail it will.
sorry I should show this first. my list for overheats are SOP, for 100years.
https://fixkick.com/overheating.html
#1 is bad thermostat the top maker tells this is 7 year life part (the wax pellet inside does not go 25 or 30 years ever,) so is #1 really, if old.
in truth, any of those can fail even 2 things, failed. (1989 cars are old)1995 is 25years old
SIGNS matter first.
sure check the cap first, its only 1minutes work to replace, new cap in hand and $10 or less cost sure... a slam dung but trip to the store.
but there are lots of thing to go , no trips to any store.
overheats only parked but not driving fast?
coolant hits the ground from engine (not just the overflow bottle)
engine cold lit it warm up hood up do not drive, let it reach 180f, normal temp.
now the top rad hose is hard squeezed by hand, if not the system will not hold pressure find that now.why)
if hard top hose (12psi there ) then the cap is good. (if not leaking to side overfill tank NOW)
then let car idle for 30mins, look every where for leaks. even the dash board heater core leaks to passengers toes. is a TOP SIGN of CAUSE.
look at the engine oil dip sick , chocolate milk is bad sign. (super bad)
look at tail pipe end., now, see steam there> on a hot normal engine you have coolant leaks in the intake man or head.(or gasket there)
signs are plenty.
if not sure about the head do a COMPRESSION TEST. (no engine told just 95) 155 to 185PSI is normal 8v to 16valve .
BEST IS TO NOT DRIVE THAT CAR, UNTIL FIXED. OR RISK WARPING THE HEAD.
if the side tank blow coolant cold the engine is damaged (head warps and its gasket fails)
this is winter if not running 50% anti freeze ,the coolant will freeze to ice and that expands and wrecks many parts.
TB cracks.(throttle body) has water heating hoses.
Intake man cracks
head cracks. and more.
the block cracks too.
99% of the time if the gasket on the CAP looks ok no cracks or not missing , it is ok that spring inside is like zero chance of failing. just the rubber seal there.
what matters is all signs , even testing just parked, not driving and risking wrecked head, tops my list.
here is my first hit list on life spans 1995 to 2020
thermostat. bad , cap rare but look. (7 years and STAT is STUCK closed ouch)
hoses, cracked, or simply loose.
rad tank top and bottom crappy plastic seals leak, hell they all did long ago.
freeze damaged. (well toss a coin on extent of damage not keeping coolant at 50%)
fan clutch dead, fails at stop signs for too hot. but not moving fast.
rad cores clogged. (IR gun test find this easy , super easy a $15 tool) see my thermo-gram pages.
water pump blades inside rusted to NOTHING left,. (bad coolant super old did it... zero service cars.)
coolant to ground or to oil pan or steam at tail pipe end, are all tops signs as is your side tank explosions. (overflow blow out) hint all signs MATTER. ASM.
YMMV too.