Brake Fluid Flush When?

I've been searching this forum for a while, and can't find anything on this question: When is it advisable to replace the brake fluid on the 4Runner? Official maintenance schedules make no mention of it, and I haven't seen it discussed.

 

It's time when there is too much water in the brake fluid!
Brake fluid is hydroscopic, that means it sucks water or more likely moisture out of the air.
Water isn't good since it boils and expends so your break system will fail. Within a year after purchase you new vehicle you'll gain around 2 percent of water in your system. I test from time to time (every other oil change) but after 5 years I would swap it for sure!
You can get a tester for that, they start at around 7$

 

Every single vehicle I owned or own gets about an every to bi seasonal brake fluid flush along with coolant, power steering, diffs, transmission, transfer cases, slave cylinder. Fluids are cheap and plentiful. Repairs due to lack of maintenance are costly. And BTW I also do 3000 mile oil changes.

Brake fluid flushes are easy. Just start at the wheel furthest from you master cylinder and work your way to the closest one. I also recommend to activate your antilock brakes occasionally to prevent corrosion. Another tip is to use DOT 4 or 5.1 fluid as they both have higher boiling points than DOT 3. I would not use RBF 600 or 660 as they are for race applications and absorb moisture at quicker and higher rate.

 

Never. You can drive your truck for 200K miles without ever flushing the brake fluid and you'll be fine. Ask the high mileage guys how often they've done it.

 

I think I had it done on my Sequoia around 100k?

I've done all the fluids per the maintenance schedule on the Sequoia.

I've only got 18k on my 4Runner so I'm a ways off. But keeping fresh fluids on a vehicle is a good thing.

 

Why would you do that? Your brakes will not be performing at optimal and safe parameters. Your braking distance will be lengthened and your components such as caliper pistons/bores and master cylinder will be worn and corroded.

OTOH it is up to the owner whether they take pride in keeping their vehicle mechanically sound or running it all clapped out. I prefer to do a little extra work for myself and families safety and prevent high repair bills.

I typically get 300,000 miles plus out of my vehicles. I am of the opinion it is foolish to tempt fate by trashing a vehicle by not maintaining it properly.

 

I would say the first flush should be around 3-4 years, and then do it every 2-3 years thereafter. If your brake pedal starts to feel "heavy" or difficult to fully depress it's time to flush.

 

Agree, still havent changed my break fluid for my wife's 2013 yaris with 92k miles as of today. And also back then I had my 2015 Civic SI with 220k and never changed the break fluid either but then I sold it since I got my 4Runner. I'm still alive and doing well.

 

Some sources on-line claim that these low end testers are not reliable, and you are better off getting it tested by the dealer . . . . However, that source may have been a dealer.

 

You're right, but its as always: there is unreliable crap in every price class, especially on the low end but a little research before purchasing will help. Sure thing is that a good shop will have a reliable tester and will test it during a maintenance job or on request!

 

I do not recommend a tester. Simply look at the color. Dark fluid is dirty fluid. Also over time brake fluid breaks down just like motor oil due to heat. While your brakes are a closed system the fluid still gets dirty through the plastic MC reservoir, rubber seals and hose pores.

It is only about a 15 - 20 minute job to flush. Simply tie a half hitch in the bleed hose, crack the bleeder open and slowly pump the brakes. The knot in hose will prevent bubbles from entering caliper. Just keep replenishing MC until the fluid comes out same color of new fluid added. Close nipple move to the next one and repeat. You will you will use just over a quart on your 4Runner. Short wheelbase vehicles get away with a quart.

"Please note": you are going to see an air pocket just like my picture. It is not drawing air into the caliper. As long as you see a small amount of fluid in the "saddle of the knot" you are good to go.

As you can see for 6 bucks a quart DOT 3, 10 bucks DOT 4 or 20-30 bucks DOT 5.1, and less than 30 minutes of your time it is very simple, cheap and quick maintenance.

The only reason not to do this is sheer negligence, laziness, and not caring about yours or your loved ones safety. Not to mention vehicles health.

Think about this: For the price of 2 cups of Starbucks and the line you wait in, this simple task can shorten your stopping distance and extend the life of you components.

 

First I have seen of this approach. As I am sure you are aware, the common method advised to prevent bubbles is running the tube into a plastic bottle with the end submerged in brake fluid. You pump the brakes to build pressure to push the brake fluid out, so under what conditions is a vacuum created that would suck air or fluid back into the bleeder valve? That's what is implied here, but I can't see that it is happening in any of the demos I see on YouTube.

As to your method with an overhand knot in the bleed hose, I can't see how this would prevent air from entering back in to the bleeder valve if a vacuum is applied. Either air would bubble through the fluid in the saddle, or the segment of fluid in the tube would just displace towards the vacuum, and the air in the tube would be drawn in. Help me out.

 

Generally it is recommended that you flush every 2 years.

 

I think it is important to take care of your vehicle but what you are doing is overkill. I do oil changes for the first 2-3 times at 5k miles when there is more wear on the new engine but after that every 7.5-10k is more than enough with synthetic oil.

I'm all for taking care of your car but no need to shame anyone else here or tell them that they are a danger to those around them and their families. You can be anal about your stuff without trying to talk down to other people who are doing the recommended amounts.

 

You are thinking of the pump up, loosen bleeder, tighten bleeder and repeat. My way is much simpler. You loosen bleeder and let gravity fill the hose. Keep it loose and slowly pump the brakes. Refill reservoir as needed. When the fluid comes out clear move to the next one.

Hello Christian, I'm not meaning to shame anyone here. Dirty/broken down/moisture induced fluid and not doing regular flushes is a risk. Brakes degrade slowly and are a lot of times are not noticed by the driver.

I do a lot of braking drills in not only my cars but also my motorcycles almost every time I'm behind the wheel or handlebars. Fresh fluid and/or brake components such as pads, lubed slider pins, caliper piston seals, etc always has the vehicle stopping in a shorter distance than before. It's all about stopping distance.

And yes it is an unnecessary risk to prolong brake maintenance. It's all about being pro active and negating the risk to you and others. And anyone who thinks it's ok to go 200,000 miles on brake fluid is only fooling themselves.

 

I just do it when its time to change brakes.

I'm working on it anyways.

 

I'll probably do it at 100k miles. Never had any issues with brake fluid in my vehicles.

 

I found a maintenance schedule online, either through toyota.ca (Canadian website) or through my dealership's website. It says every 48k km (30,000 miles). If you go by a schedule of changing your oil change every 8,000 km (5,000 miles) or every 6 months then this would mean a brake flush every 30k miles or every 3 years (every 6th oil change).

On a previous vehicle I decided not to perform a brake flush. Then one day I was ripping down some gravel roads as if I was some sort of rally racer, and I boiled my brakes. I hit the brakes heading into one corner and my foot just went to the floor. I went across the road and to the opposite ditch. Needless to say I believe in the importance of a brake flush since then. I had that vehicle for less than 5 years and it had less than 200k km (124k miles) on it.

 

Again doing brake checks "Everytime you are behind the wheel" speaks more to your need to be anal or OCD than anything else. The recommended amount is every 30,000 miles. Unless you are driving 120k miles a year, you don't need to do a brake flush "every season or bi seasonal" (which would be 8 flushes a year) That's absolute insanity

 

No. The pedal went to the floor because the fluid boiled (too much water had absorbed). After a minute or two the pedal stiffened back up and the brakes were functional once again. But it did feel exactly like you said, as if there was no fluid - or if someone had left air in a line and the brake is squishy.

 

Water cannot but water vapor is and will act like air in the line.

 

Hi Kevin, The words "never had an issue" is painting a broad brush. This blanket statement gets thrown around a lot on forums. Do you have stopping distance numbers? Consistent comparison from new until worn? Most drivers don't. I have certain off road and paved areas that I get consistent readings for stopping distance, brake lever/pedal feel, suspension settings, jetting, tires etc.

I am sharing my experience which is based on true numbers and not guessing just because "they worked".

Boiling fluid will cause a loss in braking and in extreme cases cause loss and lever/pedal being pulled all the way in or going to the floor due to vaporization.

Christian, it's called braking drills. I learned them from a young man in the Navy CB's. I have continued them and have worked a bunch of other drills and habits into my routine such as SMITH training. It is what separates the professional drivers from the average motoring public.

Let's face it, most people just start up there car and pull out of the driveway. That is an example of your average motoring public. Components deteriorate slowly and by the time it's noticed the repair bill is high or it fails altogether.

A professional driver, does a walk around and checks lights, fluids, lugs (for rust. a tell tell sign of loose ones), steering, brakes, tires, etc. The walk around is also good to ensure there is not a child/animal or debris under the tire or behind the car.

 

Brake checks, braking drills - whatever - you knew what I meant by it. Again no one here other than you is claiming they are professional drivers. Not only that, no one is comparing their 4Runner to a performance car that needs to be checked that often as they are driven typically between 35mph and ~80mph on a daily basis on paved roads.

Do I check things on my car? Yes. But not every day, every week or even every month. Do I check a little more after going off-road where it is a bumpier road that might shake shit loose? Yes. Doing regular scheduled maintenance is what will keep your cars running. Being anal and doing "braking **DRILLS**", walk arounds every time you get in the car is overkill and frankly like I said is OCD-like tendencies.

I do all the work I can on my car myself as I have learned to do since before I could drive with the help of my dad. This includes the basics like oil changes and have gone all the way to replacing the clutch in my first car ('99 corolla) because my older sister claims none of us taught her to not ride the clutch in between shifting.

Really all I am trying to say is stop talking like you're the god of car care/ repair on here - majority of the people on here do their own work or atleast try to do what they can. You can go ahead and waste your time and money doing things 5x more often than recommended if it makes you feel better and safer. But this is not what is required to keep your 4Runner running well and without issue.

 

Bingo

 

Just ignore this guy. He's a professional on every topic and writes a dissertation in every thread. Obviously craving recognition and attention.

 

Guys please take your trolling posts somewhere else. You don't have to agree with me. I'm sharing my experiences and sharing mechanical tasks to help other members here. If you do not have anything constructive to add or help, then at least please refrain from the personal attacks and name calling.

Take it to a PM instead.

 

Here we go again. Anytime someone calls you out, you play the victim then start bombarding them with PM's. Name calling? Lol.

 

FYI...It's easy to click on someone's user name and select "ignore".

You don't have to see their posts if you don't want to.