Brake fluid is hydroscopic, it readily absorbs moisture from the air, so it should be changed every other year along with the coolant, even it the car isn't driven. Annually or before a long trip. Check belts, hoses, fuel lines, engine, transmission & differential oil, transmission bushing, flex disc & center support bearing. Inspect for fluid leaks & either try to fix or clean to monitor them. I try to be vigilant with all this, yet sometimes something fails & it's time for a phone and a flatbed.
brake fluid is, yes, but not as much as needing such frequent changes, if your system is air tight and if you do not open the cap of the reservoir every two weeks (people do odd things, so better explain this too), brake fluid will keep properties for more than 6 years
some good advices here, Andrew,
“Annually or before a long trip. Check belts, hoses, fuel lines, engine, transmission & differential oil, transmission bushing, flex disc & center support bearing. Inspect for fluid leaks & either try to fix or clean to monitor them”
i would say it is easy to check once a week,
fluid drops in the floor, also as you said clean the droping point and the path of the spill, so you can recheck next week or after a drive and see and understand the cause
check tension of the belts is easy and important
check fluid levels, including the not so evident steering fluid
it is good to paint a mark in the lateral of the coolant reservoir and check it with cold engine
fluids tend to diminish, never increase, if you check the levels regularly you will have criterion as to what is correct or unexpected
for carbed cars do not be afraid to open the air filter box now and then and take a look to its back and to the top of carbs, look for fuel marks (here 98 oct fuel is blue colorant, so if you see a trace of blue in those surfaces, time to check regularly or try to find the problem)
check the usual spots of the brake/ clutch rubber seals, as the brake pump, and clutch master, rare but possible, check pedals area inside the cockpit for spills
check battery for vapour/ spills if hot weather,
check distrib outer body for oil drops
check the cables that provide electricity to carbs, also the hoses for advance/retard
put the correct air pressure in your tyres
as to performance, feel and compare, usually the first time in some days/weeks you drive your coupe the feeling will not be 100%, i find that the next day the drive will be close to perfect, and that after the third day the car will give his best performance
if something surprises you (be in the eager to be surprised mod), note it in your head, feel it, and search for it in your next drives, if it dissapears, ok, if persist check it (i once had a wissling noise coming from right front wheel, i reproduced in slow movement in the garage, and found it was a leaf blocked between the brake pads and the disk)
as
@Dick Steinkamp said these cars deteriorate quickly if the are not driven regularly
fluids are cheap, but changing them is laborious, and if you ask someone to do it for you, expensive too
i am in favour of changing the fluids as frequently as you can/want
spark plugs are inexpensive too, and everytime you replace them with new ones you are checking how they are working in your engine
points and condensor are more problematic, you can check points visually, but condensor is more difficult
checking the points gap, ignition point, and carburetor settings is a nice exercise if you can do it by yourself, i do all that once a year
valves gaps are another thing to check, but i must confess that i am more reluctant to do it regularly, probably once every 10.000 km would make perfect sense, but is laborious, and i always have the feeling that i am low at the learning curve every time i do it and that as soon as i finish i am in the pro degree again but hopeless because i will forget the details before i reach the next operation 4 years later
