mark79,80

I have silicone brake fluid in my 1980. To extend the life of the brake components, should most of the fluid be removed from the master cylinder, fresh fluid added and the the bleeders at each caliper opened so fresh fluid reaches the calipers?
If so, how often should this be done?
Should only one brake bleeder be opened at a time starting with the right rear, or can all the bleeders be opened at once, and keep adding new fluid to the master cylinder to maintain the level?

wadenelson

Every five years is about right, shorter for DOT-4, longer for silicone. DOT-3 / DOT-4 is hygroscopic meaning it sucks water out of the air, which then rusts the lines, pistons, calipers, etc Never re-use a can, always open a fresh one.

One brake at a time starting the furthest away from the master cylinder.

With a lift and a helper you can do a brake bleed in 30 minutes provided you don't screw up and pump the MC dry.

Personally I stay away from vacuum bleeders, power bleeders, etc.

Or you can just pay a reputable brake place $100 to do it and be done.

ABS brake systems are a whole other animal, requiring a scan tool to actuate the valves in the ABS unit.

**** ADDITION

One invaluable tip. Whether your bleeder screws are 5/16" or whatever size, invest in a extra LONG six-point combination wrench to break them loose without stripping. Name brand, like S&K or SnapOn. Decide beforehand if one's gonna strip if you're going to walk away from that corner, try the Vise Grips, or extract it, buy a new caliper, whatever.

HeadsU.P.

I believe the experts say every 3-5 yrs. No body does it. But its good preventive maintenance.
You can use the gravity method and do all six bleeder screws at once. Slide clearing tubing over the fitting and into a water bottle. Crack open the bleeders. Never let the MC go dry. Close off the nearest bleeder to the MC first when done, then the farthest because you are not removing bubbles, just refreshing fluid.
Pack a lunch, it will take awhile.

Sayfoo

I would venture a guess that 99% of all cars on the road have the original fluid.
Now, this does not mean that changing it is a bad idea or nor worth while, but there is no need to go over board either.
Some race cars get changed before each race, but for street cars ?????

cv67

Guilty....Only flushed 1 car once in my life as pm. Figure a caliper will probably leak at some point and have to do it anyways. Thats my lazy excuse.

Duane4238

My wife came home from the Honda dealer the other day after an oil change. They told her she was overdue for a brake fluid change at 18,000 miles. She knows better and said she'd have to come back. They said it would only be $164.95 + tax. Unbelievable the crap they try to pull on people. Her vehicle is a CR-V and a lease to boot.
Duane
By the way, I've only changed fluid in my '72 one time and that was when I went to stainless calipers.

mark79,80

Based on the replies, I will wait longer before changing the brake fluid. I last changed it two years ago. Thanks for the advise everyone.

7T1vette

If the brake system is in good shape, you only need to consider changing silicone fluid whenever you need to change brake pads. That will be the first thing to wear/deteriorate...unless there is some other problem with the brake system. Bleed a bit of fluid out to check its color and clarity. If the fluid looks fine and the pedal is still hard, let it go another 'round'.

Rescue Rogers

This is good advice. When I bought my car it had the purple fluid in it and the brakes were horrible. Turns out a good portion of it was water and I had to flush the entire system to get it all out.

HeadsU.P.

7T1 is correct. Any time you are questioning when to change the brake fluid, let the MC be your guide. Just pop off the lid on the MC. If you can't see the bottom of the "rez" its time.

If you don't change the fluid every so often, the pistons in the caliper bores refuse to retreat when you release the brake pedal. Then you get that smell from a dragging brake pad.

wadenelson

Where DIYers typically screw up installing new brake pads is they don't crack the bleeder before pushing the pistons back into the caliper. This pushes rusty, contaminated fluid back up the lines, into the ABS, MC, etc.

Always crack the bleeder screw first, with a hose into a jug, etc. Hang the jug with a coat hanger or whatever.

And then, BE SURE to top up the MC AFTER you install the new pads and pump up the brakes BEFORE you go to drive off the lift, whatever.

Don't ask me why I remind others to remember to pump up the brakes. If you'd seen me repeatedly slamming a customer's car between reverse and forward, loudly squealing the tires because I had no brakes, having failed to pump them up, with a busy street behind me and a car wash / vacuum cleaner set in a concrete island in FRONT of me, you'd understand. (The entire time I was pumping like a madman...)

Only one guy in the shop saw me do it and he's kept his mouth shut some 30+ years...

wadenelson

It's all about whether its a street car you intend to get rid of in 2-5 years, like "99% of all drivers" or an heirloom you plan to keep for 20 and hope to sell for more than you paid for it.

Sayfoo

Not really. Over maintaining your car doesn't really add anything. And, with our 50yr old cars, it's easy to mess up or break something that you may have to replace with a cheapo chinese repo part.
Appropriate maintenance is best.
It's your car, do what makes you feel good.

cvm

6 point socket vs 12 point very crucial to not strip bleeder.
please use 6 point

terrys6t8roadster

My blue car [ complete Wilwood system] has DOT 4 and it gets bleed every 3 to 4 years, now on the other hand the 9-car has DOT 3 and has never been changed since the brakes got a minor upgrade which has been over 5 years. T

ED DINAPOLI

You asked about changing Dot 5, silicone fluid. I have Dot 5 in my 72 that still has the original MC, which has never been rebuilt. The Dot 5 was installed in 1985 and has never been changed. It was added to, when I changed pads, but never drained. If you remove the MC cover you can see a clear clean fluid with no rust. The only thing that is different is the original color has faded.
Ed