Recommended mileage for brake fluid exchange?

[n2zon]

Originally Posted by Winemaker2

Brake fluid is a pretty inexpensive part of a critical safety system.
Why would you NOT perform recommended PM by replacing it?
The stated reasons are factual... the naysayers and anecdotal stories have been fortunate they got by with less than best practices.
I'd be willing to bet many would never bother lubing a slide pin on disc brakes unless there were problems / failure

^^^ Yup.

The moisture meter aside (gotta get me one of those!), there are only two ways to know you didn't change the brake fluid often enough.

The least expensive is that a caliper or wheel cylinder will seize and fry the brake pads or shoes on one corner (usually followed by the other three, eventually).

The most expensive involves bodywork, if you're lucky, and bits and pieces of fiberglass and other stuff spread over a fairly wide area if you're not.

[SeeTheUSA]

Since manufacturers have gone to the plastic master cylinder reservoirs it’s easy to see what’s going on visually,, so I decide it’s time to change brake fluid based on color … if it looks lightly colored like honey, good for now. When it’s colored darker, more like Log Cabin syrup, then it’s time to change it.

Here’s a technical article that might help:

https://rxmechanic.com/brake-fluid-color/

[bigb56]

Originally Posted by SteveJ.

I bought a brake fluid moisture meter. It takes the guess work out of when to purge the fluid. Currently $13.99 at the big A.

https://smile.amazon.com/gp/product/...?ie=UTF8&psc=1



A note: do not stick the meter in farther than the tips of the probes. Folks have had the tester go bad from dunking it in too far.

I have one of those as well but I am not altogether convinced that the fluid up in the plastic reservoir is an accurate representation of the fluid trapped in the steel parts and caliper where it gets much hotter, and debris/sludge can collect.

[wolfe10]

Originally Posted by bigb56

I have one of those as well but I am not altogether convinced that the fluid up in the plastic reservoir is an accurate representation of the fluid trapped in the steel parts and caliper where it gets much hotter, and debris/sludge can collect.

Yup, two places that moisture enters the brake fluid:


Master cylinder reservoir and the brake calipers/cylinders. No way short of bleeding the brakes to determine the latter.


AND, the latter is where brake fluid condition is CRITICAL, as that is where the heat is generated when braking and where hydrated brake fluid can boil.

[youracman]

Not a direct response to the OP, but related:

I replaced the front rotor/hubs, pads, calipers, bearings & seals on my E450 some years ago (daughter warped the rotors in mountain driving) and found a power bleeder to be a really nifty tool .... especially for those of us who work alone. Saves a LOT of trips to and from the underside of the chassis. I flushed it with denatured alcohol when finished (as recommended) and used it the following year to do the rears, so it is a "keeper" kind of tool. The adapter (that connects to the fluid reservoir) fit my Ford perfectly; but, you might want to check the Application Guide PDF via the link on the bottom of the Amazon page to be sure for your rig. If different, you can order the basic pump and adapter separately. For me, it removes a lot of the "dread" from flushing/changing the fluid; matter of fact I usually do a 2nd short bleed ...... just to be sure.

There are several brands out there; this just happens to be the one I used:

https://www.amazon.com/Motive-Produc.../dp/B00CJ5DZE2

Safe travels all.

[Ray,IN]

Ford, Mercedes, and several other auto mfgrs have a brake fluid change interval in the owners manual.


I found out the hard way, towing 40' 5er with my Chevy dually descending to Skagway AK. Brake fluid got hot, lost braking ability, burned up trailer brakes trying to slow down.
When things cooled I had brakes again. Drove to Whitehorse and had everything fixed, $1,000 later I was back on the road, with clean shorts again.