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SantinoDad · 10-24-2022, 09:58 PM

2016 Winnebago Minnie Winnie 22r on a Ford E350 Superduty 5.4liter V-8

Recommended mileage for brake fluid exchange?

I am now at 30,000 miles

**Camp CA** · 10-24-2022, 10:24 PM

Suggest downloading your chassis maintenance manual to be sure. My 2021 Ford F53 V8 chasis maintenance manual specifies changing brake fluid every 3 years.

twinboat · 10-25-2022, 12:18 AM

Brake fluid flush is done by age not mileage.

As far as I could find, only the F53 " Motorhome " chassis has a brake fluid flush requirement.

FLYING BUTCH · 10-25-2022, 04:42 AM

I've been driving for over 60 years and never once changed brake fluid and have no plans in doing so. I see no purpose in doing so?? My current pickup, I purchased new and it has 250,000 miles on it. To me this is makes has about as much value as changing engine oil every 3,000 miles or running premium gas in a car that does'r require it. Just my two cents from an old timer.

safe travels all

David 70 · 10-25-2022, 05:33 AM

You say ou have been driving for 60 years. Back in your early days your brake fluid got flushed every time you had a brake job done on the old drum brakes. I done many a brake job when I worked in a gas station (full service at that time). All the brake cylinders got rebuilt and then pressure bled until new fluid came out. If you ever have your brakes go out on a 30,000 lb. motor home you would change your mind. A pickup does not see the heat buildup that a motor home does. Please people for yor sake and everyone else on the road with you check on that fluid and change it.

twinboat · 10-25-2022, 05:57 AM

Brake fluid is hydroscopic, meaning it absorbs moisture.
A simple Google search explains how moisture content effects the boiling point of brake fluid.

In most cases, fluid is changed during brake jobs, so not a big problem.
Did you know that your supposed to open the bleeder as you collapse the caliper pistons ?

In RVs, that have very limited use, a brake job may not be done for 6 to 10 years. During that time moisture is slowly accumulating in the fluid, lowering the boiling point.

During a long or hard stop the fluid will heat above the boiling point. If you let up the pedal, the fluid turns to steam, pushing it back into the master cylinder.
On the next application of the brakes, you have steam pockets in the calipers and the pedal goes to the floor. Once it cools and you pump the brake pedal a few times, all goes back to normal.

Been there done that on my 1999 motorhome.

n2zon · 10-25-2022, 06:30 AM

Quote:

Originally Posted by twinboat

Brake fluid is hydroscopic, meaning it absorbs moisture.
A simple Google search explains how moisture content effects the boiling point of brake fluid.

In most cases, fluid is changed during brake jobs, so not a big problem.
Did you know that your supposed to open the bleeder as you collapse the caliper pistons ?

In RVs, that have very limited use, a brake job may not be done for 6 to 10 years. During that time moisture is slowly accumulating in the fluid, lowering the boiling point.

During a long or hard stop the fluid will heat above the boiling point. If you let up the pedal, the fluid turns to steam, pushing it back into the master cylinder.
On the next application of the brakes, you have steam pockets in the calipers and the pedal goes to the floor. Once it cools and you pump the brake pedal a few times, all goes back to normal.

Been there done that on my 1999 motorhome.

Having had the fluid boil once (on a race track), I can assert that it's a, um, memorable experience. The fluid boils the instant your foot comes off the pedal and it goes straight to the floor the next time you try to brake. They won't pump up immediately no matter how frantically you try to pump them up. (Keep trying anyway, of course.)

As twinboat says, the pedal will come back when things cool a bit. This can take a minute or two. That's a really long time in a motorhome that won't stop.

I learned three things that day. First, it was possible to go a *lot* faster around that corner than I thought. Second, change the brake fluid on a tracked car more often. Third, go easier on the brakes to keep this from happening!

This is one reason we're told to brake intermittently on long, steep hills and use alternative, supplemental ways to control speed. The other is to keep the pad or shoe material temperature inside its effective operating range. With "wet" brake fluid it's a race you lose either way.

There is lots of misinformation out there, but Tilton Engineering has it right: https://tiltonracing.com/brake-fluid...e-and-go-fast/ You can disregard their suggested brake fluid change interval for a coach, since we rarely race them (grin). Just do what the manufacturer says.

Mudfrog · 10-25-2022, 08:17 AM

Quote:

Originally Posted by FLYING BUTCH

I've been driving for over 60 years and never once changed brake fluid and have no plans in doing so. I see no purpose in doing so?? My current pickup, I purchased new and it has 250,000 miles on it. To me this is makes has about as much value as changing engine oil every 3,000 miles or running premium gas in a car that does'r require it. Just my two cents from an old timer.

safe travels all

I tend to agree with you that 2 and 3 year recommendations are probably overkill. Until earlier this year, on my 2003 motorhome, I had never replaced brake fluid in any vehicle that I have ever owned. My 94 Jeep's brake system has never had a real brake fluid change. I've added a bit over the years when replacing shoes and pads but that's all, never a flush. Have never done anything with the brakes on my 01 Jeep except to visually check the fluid in the reservoir periodically.

Yes, brake fluid is hydroscopic. But I have to wonder how much contamination can occur in a proper functioning brake system. I've read that phenolic caliper pistons can let moisture in and I'm sure, under the right circumstances, can cause problems. Still, how often does it actually?

I definitely agree with you with the 3k oil change and use of premium gasoline.

youracman · 10-25-2022, 08:59 AM

Not that it makes any difference folks, but brake fluid is hygroscopic.

End of spelling lesson...............

wolfe10 · 10-25-2022, 09:10 AM

Quote:

Originally Posted by Mudfrog

I tend to agree with you that 2 and 3 year recommendations are probably overkill.

Part of that answer depends on where you live and where you drive.

Humid climate? Drive in rain? Live in the desert? These will effect the "what is the maximum time I should go between brake fluid replacements".

Certainly erring on the side of caution will add to safety and brake component longevity.

chuckftboy · 10-25-2022, 07:23 PM

I have always flushed and replaced my brake fluid every 5 years in my vehicles, just thought 3 years was a bit too soon. My thinking is brake fluid is cheap but body work isn't.

bigb56 · 10-25-2022, 07:44 PM

I drive in mountains all the time and follow the Mercedes schedule of new brake fluid every 2 years. Also I buy the brake fluid in metal cans and once the can is opened, if I don't use it all the rest is trash and goes to the hazardous waste disposal. Not playing games with expensive components and grades as steep as 10%.

SteveJ. · 10-25-2022, 07:47 PM

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.

Winemaker2 · 10-25-2022, 07:48 PM

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