Lazarus Long

My 98 now has about 19000 miles. It was my Dads, bought new. I have been changing the oil yearly, but no other fluids. I always ask if the other needs it, they always say "no, it's fine". I don't know when fluids were last changed. Possibly coolant has been changed, I'm less confident that brake, clutch, power steering, or differential has.

Even though the mechanic says it is all ok, should I consider doing it anyway? It is about due for its yearly oil change. It has not been driven hard, and is stock. M6 transmission.

Vetteman Jack

I would change all the fluids if it were my car - after all, it is a nearly 20 year old car albeit with low mileage. The coolant should be changed every 5 yrs, 150K miles, whichever comes first. And the brake fluid/clutch fluid most likely needs it too. According to the owner's manual, the manual tranny fluid never needs changing - if you're comfortable with that, fine. I changed mine when I had my six speed car even though I probably didn't need to - just made me feel better about the maintenance on the car. Not sure about the power steering fluid - can't hurt (other than a hit to the wallet) to have it changed.

Corvette#2

I would change everything. New transmission fluid made my car easier to shift gears. Really worthwhile. I changed the differential fluid for peace of mind. The first owner had changed the original coolant and replaced the hoses. I drained and refilled the coolant again per the service schedule. When it needed a brake job, I put in fresh fluid. Clutch fluid I used the ranger method. All in all, it's cheap insurance.

RonDZ06

You don't need an endoscope to see the valve springs. Just shine a light into the oil filler cap and look.

RonDZ06

My first related thread post goof I'm guessing? Lol. Swear this wasn't thread I posted in.

kh400

I change all the fluids yearly. Cheap insurance.

GettnBetter

Defintely flush the brake fluid, in a 98, it died around 20 years ago and is definitely unsafe, they will fade or grab on one side the first time you really need them and being soo old, make sure they activate the ABS or you'll have most of the old fluid still in the system. Coolant lasts 5 years, that should be flushed. Trans and rear end probably last forever but if it starts being difficult to get in reverse, it's a sign the tranny needs new ATF (not synthetic, it will destroy the paper blockers but Amsoil ATD is safe). If under high power levels when turning, you get rear end chatter, replace the diff fluid with the proper additive unless the fluid includes it. Power steering fluid will last 100 years and never needs replaced, that's usually something a service salesman tries to get a bigger commission. Clutch fluid is probably a good idea, I forget if the C5 needs the ranger method or not, it's been a while since I've done anything to my C5 but clutch fluid absorbs moisture just like the brake fluid.

_zebra

unless the slave already has a speed bleeder installed, ranger is the quicker/easier (albeit not as thorough) method for flushing the clutch fluid.
i installed some Russell speed bleeder valves on the calipers - makes brake flushing a one-man job & well worth it.

RPGR90s

DOT 3, 4 brake fluid absorbs moisture so annual flushing ensures a moisture free system.

Does this matter?

Well, as proof, I've been doing this on my old BMW motorcycle for quite a few years. (1974 R90s). About twenty years ago I decided to take the front brake calipers apart and check on the pistons, seals, etc.

When I popped the pistons out, the surfaces were literally like new. No pits, corrosion at all.

So once a year, I get my wife to pump the pedal while I bleed all four corners until clean fluid comes through.

Cheap insurance IMHO

ssmuff

I changed all the fluids after purchasing the car. Honestly, I was worried someone didn't change them over the years so for a few $100's it was something fun to do and worthwhile. This winter all I've changed is the clutch fluid and the brake fluid. Buy yourself a fluid extractor and you can change the fluids fairly often and makes the jobs simple. I will replace the engine oil and filter before spring hits.