Brake Flush Question

[Snagglefoot]

I've only done two brake jobs and they were many years ago. What pitfalls should I be aware of?

The scariest part is you put the wrench on the bleeder and it doesn’t want to turn. You might want to spray some penetrant on the threads way ahead.
New bleeder screws are not expensive so if you sense the threads have rust on them from the caliber body, you might want to replace them. The other thing is after bleeding you want to snug the bleeders down appropriately so they don't leak but don’t go ape on them.

 

[ARCOgraphite]

Bring it to the dealer or trusted mechanic. A no fun job generating toxic and hazardous waste. Typically a two person job. You don't want to mess this up.

 

[RaymondP]

Key is NOT letting air into the system and removing any air from the system, usually at the bleed nipple. Also, important to get the correct order of bleeding at each of the four corners, usually furthest from the brake fluid reservoir first, then second furthest, and so on. It does make a difference, and each vehicle is specific on this issue.

 

[Rand]

I've only done two brake jobs and they were many years ago. What pitfalls should I be aware of?

actually breaking the bleeder(loosening or when tightening)
Air in the calipers, air entering master cylinder if it gets to low
correct sequence to bleed(which wheel to start at first)
if you get any brake fluid on paint it will dissolve the paint.

are some of the main ones.

For as much as we complain about dealer prices.. brake flushes are almost worth the $$$.
Was just quoted on the 2020 ram
$180 and they clean and lube too.

 

[The Critic]

For as much as we complain about dealer prices.. brake flushes are almost worth the $$$.

Maybe in the rust belt…

 

[Rand]

Maybe in the rust belt…

Yes. a "fuel injection service" is $160 flushing the brakes and cleaning/relubing = 180

600$ to change the diff oils and transfer case oil

you see where I'm coming from saying its a relative value.

I've had good luck using the tubing with bottle method. if done correctly there is no way to introduce air to the caliper.. and you have someone watching the master cylinder.. I rarely bleed brakes.

 

[Artem]

Sometime in the next few months, I'll be doing a brake job on the Camry. When flushing the system, is there anything more that's needed other than running clean brake fluid through the lines and calipers? Would some sort of cleaner or solvent be useful to get the lines really clean? I'm asking because the car has had questionable, and possibly poor, maintenance during the time before I purchased it.

Nothing more can be done except pushing out all old brake fluid with fresh oil.

If the brake reservoir is THAT DIRTY and contaminated with build up, the best you can do is extract the old oil and try to wipe out as much crud as you can easily reach with a clean, lint free towel.

Otherwise just leave it dirty, drain and refill with fresh brake fluid and call it a day.

Removing old moisture contaminated oil is the main point.

 

[edyvw]

It is too cheap to do it any other way:
Pressure bleeder

 

[sloinker]

Unless you plan on going 200,000 miles then I don't believe internal rust due to the hygroscopic nature of the fluid will damage anything enough to necessitate changing the fluid. If you are worried about boiling the fluid on a steep descent and losing brakes...this isn't 1962 and you don't have a single reservoir master cylinder. I have had plenty of brake systems apart and believe that once they are working well, leave the hydraulic portion alone. Granted if you are changing calipers/wheel cylinders for some reason, go ahead and use fresh fluid. I kind of think this is a another money generator for the dealership along with nitrogen and fabric conditioner, paint sealer, rust proofing, VIN etching......Keep the lid on the reservoir and use a flashlight to look through the translucent reservoir for level if you are worried about humidity infiltrating the fluid to the degree where it will cause internal rust. Another thing to keep in mind is that virtually all vehicles have ABS systems now. Not all systems control fluid in the same manner. Pressure or gravity bleeding may not expel all of the fluid without the ABS actuating. If that is the case you are leaving behind a quotient of used fluid to mix with your virgin fluid sometime in the future when the ABS comes into play.

 

[supton]

For as much as we complain about dealer prices.. brake flushes are almost worth the $$$.
Was just quoted on the 2020 ram
$180 and they clean and lube too.

Are you it is a full flush and just a D&F on the MC?

 

[Artem]

Unless you plan on going 200,000 miles then I don't believe internal rust due to the hygroscopic nature of the fluid will damage anything enough to necessitate changing the fluid. If you are worried about boiling the fluid on a steep descent and losing brakes...this isn't 1962 and you don't have a single reservoir master cylinder. I have had plenty of brake systems apart and believe that once they are working well, leave the hydraulic portion alone. Granted if you are changing calipers/wheel cylinders for some reason, go ahead and use fresh fluid. I kind of think this is a another money generator for the dealership along with nitrogen and fabric conditioner, paint sealer, rust proofing, VIN etching......Keep the lid on the reservoir and use a flashlight to look through the translucent reservoir for level if you are worried about humidity infiltrating the fluid to the degree where it will cause internal rust. Another thing to keep in mind is that virtually all vehicles have ABS systems now. Not all systems control fluid in the same manner. Pressure or gravity bleeding may not expel all of the fluid without the ABS actuating. If that is the case you are leaving behind a quotient of used fluid to mix with your virgin fluid sometime in the future when the ABS comes into play.

What are you talking about?!?! Brake fluid is literally CONTAMINATED with just a mere 3-4% water content in it.

That alone is enough to cause the brake caliper piston to slowly start seizing and result in increased brake pad wear, lower gas mileage, more engine and transmission wear, etc etc. and all of that simply due to a $10-$15 bottle of brake fluid every 3 years. WOW. Soooooo expensive.

 

[sloinker]

I literally have worked on hundreds of brake systems on all manners of makes over the years. I stand behind what I wrote. What is the boiling point of DOT3 or 4 fluid? What is its boiling point with 3-4% water contamination? How many modern calipers have you seen where the internal cylinder bore was rust pitted in a functioning vehicle where reasonable maintenance was performed minus the brake fluid flush? I have never lived in Florida, perhaps driving through hurricane flooded streets has caused for you what is a valid concern.

 

[Donald]

So what is recommend pressure brake system? Under $100. Fit my 2015 F250

 

[Artem]

I literally have worked on hundreds of brake systems on all manners of makes over the years. I stand behind what I wrote. What is the boiling point of DOT3 or 4 fluid? What is its boiling point with 3-4% water contamination? How many modern calipers have you seen where the internal cylinder bore was rust pitted in a functioning vehicle where reasonable maintenance was performed minus the brake fluid flush? I have never lived in Florida, perhaps driving through hurricane flooded streets has caused for you what is a valid concern.

I too have worked on hundreds of brake system and when I see one front caliper with pads at 5-6mill while the other side is at 2mill and then I glance at the brake fluid reservoir and see dark, green, and generally nasty brake fluid in there, I know EXACTLY why one caliper is sticking and why the owner now needs new brakes and possibly even a caliper plus a fluid flush.

Easily avoidable with a simple brake flush every few years or when new brakes are installed. Most shops don’t touch the flush and just push that nasty old fluid in the calipers BACK UP into the ABS system and call it done.

Surprisingly, that 3-4% moisture is enough to cause me to re-adjust my muscle memory on my clutch leg after flushing my brake fluid. New fluid now compresses differently and I need to relearn the clutch pedal because it now performs differently…. And I flush my brake fluid every few years on this car because it shares the brake reservoir with the clutch pedal.

 

[sloinker]

What are you talking about?!?! Brake fluid is literally CONTAMINATED with just a mere 3-4% water content in it.

That alone is enough to cause the brake caliper piston to slowly start seizing and result in increased brake pad wear, lower gas mileage, more engine and transmission wear, etc etc. and all of that simply due to a $10-$15 bottle of brake fluid every 3 years. WOW. Soooooo expensive.

I too have worked on hundreds of brake system and when I see one front caliper with pads at 5-6mill while the other side is at 2mill and then I glance at the brake fluid reservoir and see dark, green, and generally nasty brake fluid in there, I know EXACTLY why one caliper is sticking and why the owner now needs new brakes and possibly even a caliper plus a fluid flush.

Easily avoidable with a simple brake flush every few years or when new brakes are installed. Most shops don’t touch the flush and just push that nasty old fluid in the calipers BACK UP into the ABS system and call it done.

Surprisingly, that 3-4% moisture is enough to cause me to re-adjust my muscle memory on my clutch leg after flushing my brake fluid. New fluid now compresses differently and I need to relearn the clutch pedal because it now performs differently…. And I flush my brake fluid every few years on this car because it shares the brake reservoir with the clutch pedal.

You do know that fluid doesn't compress? Air bubbles do. When some person endeavors to do a flush in their driveway using a floor jack because you tell them it is vital? I disagree. There should be no air in someones brakes if the system isn't too low as it should never become. As the pads wear the distance needed to compress the pedal changes to compensate for thinner pads. Uneven wear is usually a sign of external brake hardware and lubrication issues. Asking some dude that top changes his oil and wouldn't know a triple square from a torx to flush his brakes is not something I am comfortable doing. If they do indeed manage to free the bleeder without breaking it, also manage to introduce fresh fluid all the way to the bleed without introducing air. Great! They have left a fraction of fluid behind within most ABS systems accumulator/diverter sov systems. So why bother? Keep the system closed. Replace pads when needed using new hardware and recognized lubrication techniques. Push those cylinders back in and watch your master cylinder reservoir replenish itself. If you absolutely have to, go to the dealer and give them a hundred bucks for this un-needed service. It is funny when you look online how self serving the industries are in their opinions. If you are really concerned about the hygroscopic aspects of Dot 3/4 fluid you can convert to Dot 5 which is hygrophobic. No rust, not likely to boil, found in motorcycles all over the world.

 

[supton]

I have not found that brake fluid flushes made my calipers last longer. Small sample size, but I find the calipers quit regardless if used long enough. Maybe its where I live? probably.

 

[oilboy123]

Lot of good advice.......

I would not let the reservour ever run dry. I pull fluid out of the master, then replace it with fresh. I then put a hose/container on each caliper/wheel cylinder bleed fitting. If you have ABS that is a good reason not to run master cylinder dry. Otherwise if air is introduced, you probably can't get it out of the ABS system again, without something to actuate the ABS system while bleeding. Can't comment too much on running an ABS system dry. Because I have not had the issue.

What I do is just crack the bleeder maybe a turn. Then press on the brake pedal some to get fluid moving. I don't think I'm pressing the pedal more the a few times at maybe couple of inches travel.
After that the fluid starts moving through the caliper, and it will gravity bleed. I did my daughter's Edge and had all 4 calipers flowing at the same time. This won't go through the ABS system. You can always do a pump bleed with 2 people to finish it off. I like to flush between brakes jobs. Especially with the rain where I live.

I did by a brake fluid moisture checker I'm going to start using to monitor fluid water level. My daughter bought a used 2015 Expidition, and the fluid showed 0% moisture. My 2016 focus showed a low amount. But I did flush the fluid with the newest Bosch fluid in 1 qt cans. Only because I was close to 90K and 6yrs on original brake fluid.

 

[paulo57509]

Flushing the calipers is straight forward. I wouldn't know the specifics of flushing the ABS actuator. I would assume it would depend on how it is designed.

The Lexus has instructions on how to bleed the actuator (I've never done this); the description of the bleeding procedure appears it would apply to flushing; just let more fluid flow from the bleeder screw. If I were going to attempt an actuator flush, I would use fluid pressure instead of air pressure. I'd flush the calipers first, actuator last to keep as much contaminants out of the actuator.

Salvage vehicle purchase 2005 Lexus GX 470

The Gx 470 is mechanically road worthy. Filled the coolant, and went on a ten mile drive, at speeds up to 55 MPH. No issues, steered straight, ran quiet. I likely could get her back together tomorrow if everything went flawless in reassembly. I decided to install an aftermarket trans cooler...

bobistheoilguy.com

 

[The Critic]

Flushing the calipers is straight forward. I wouldn't know the specifics of flushing the ABS actuator. I would assume it would depend on how it is designed.

The Lexus has instructions on how to bleed the actuator (I've never done this); the description of the bleeding procedure appears it would apply to flushing; just let more fluid flow from the bleeder screw. If I were going to attempt an actuator flush, I would use fluid pressure instead of air pressure. I'd flush the calipers first, actuator last to keep as much contaminants out of the actuator.

Salvage vehicle purchase 2005 Lexus GX 470

The Gx 470 is mechanically road worthy. Filled the coolant, and went on a ten mile drive, at speeds up to 55 MPH. No issues, steered straight, ran quiet. I likely could get her back together tomorrow if everything went flawless in reassembly. I decided to install an aftermarket trans cooler...

bobistheoilguy.com

There is no reason to flush the actuator as part of routine maintenance. That is a huge can of worms and is a very lengthy guided process.

 

[John105]

Confession.

When I first started bleeding brakes, I would go to the rear right, and pressure bleed it, as a first step.

One day, I watched a YouTube, and the first step a person did, was to remove some fluid from the reservoir, fill it back up, then pressure bleed the rear right.

DOH!! It dawned on me that I was bleeding old fluid out the rear right, and doing 3/4 of a brake flush!