Proper method to change your brake fluid?

[Leo99]

Originally Posted By: turtlevette
Its funny that people that think the hygroscopic nature of brake fluid is no big deal, will go nuts thinking about the e10 in their car or boat. Like lose sleep over it.



No, I think the people worrying about their brake fluid are the same ones losing sleep over e10.

 

[philipp10]

Originally Posted By: turtlevette
Its funny that people that think the hygroscopic nature of brake fluid is no big deal, will go nuts thinking about the e10 in their car or boat. Like lose sleep over it.



well I don't lose sleep over either....it's not an issue.

 

[Colt45ws]

Don't care about e10...change my fluid regularly.

 

[HTSS_TR]

Originally Posted By: Colt45ws
FI have no idea what I was doing wrong. I would use one of the little black adapters that seemed to snap firmly onto the bleeder. But I would still loose vacuum at some point in the procedure.

The black adapter is not supposed to be used like that. This was the wrong way and that why you didn't success with the fluid extractor in bleeding the brake.

You need a flexible hose that fit firmly to bleeder valve and the other end to the black adapter, the main tube from black adapter to container.

The hose that came with Motive Power Bleeder is perfect, it fits the bleeder valve tightly and fit the black adapter snugly too.

Using the Mityvac 7201 correctly you will not spill a single drop of brake fluid anywhere.

 

[Olas]

Originally Posted By: Doublehaul
I worked on cars professionally for a long long time and never heard of let alone saw people changing out brake fluid...and I am ASC certified in brakes! Its absolutely true that brake fluid does absorb moisture...but in a closed system with very little fluid movement you may be looking for a problem that doesn't exist.

I get that BITOG is the most anal-retentive forum in existence but i guarantee you that nobody outside of a very select few change their brake fluid. Where are the catastrophic brake failures and TSBs? Is this a service thats recommended by any OEMs? Im not trying to be argumentative...just curious.

EDIT...i see the gent above me had a OEM recommendation to change every 30k. Maybe this is something I've honestly just missed over the years?

As always YMMV.


In all seriousness we should have a classified section for used car sales...we have the worlds BEST maintained cars!!!


Is it possible that your customers were very stupid? Or so close to broke that they couldn't afford new brake fluid?
My owners manual states that dot4 needs changing every 24 months, and having bought old neglected cars in the past to fix up and sell on I've felt the terrifying effects of severely out of date brake fluid.

Maybe people need to feel the fear and *almost* have an unavoidable crash to believe in preventative maintenance.

 

[dlundblad]

Originally Posted By: mclasser
Honda says every 3 yrs, irrespective of mileage so that's what I go with on all my cars.

I've heard it said that bleeding the brakes via the pedal method can cause master cylinder failure, particularly on older cars since it's not good to let the pedal drop to the floor. I think there are TSB's for newer cars as well. Easiest & safest method is vacuum bleeding. Brake flushes are the only fluid change I don't DIY on my cars; it's nasty toxic stuff that eats paint. I gladly pay my indy to do it every 3 yrs.


I had never heard of bleeding the brakes like this causing master cylinder failure. This is making me look into some sort of brake bleeder.

 

[Doublehaul]

We worked on Domestics 99% of the time...perhaps explains why

 

[Carmudgeon]

Originally Posted By: HTSS_TR
Owner manual of E430 and S2000 clearly have maintenance schedule for brake fluid. MB recommends 2 years with DOT-4 and Honda recommends 3 years with DOT-3. Either one has unlimited mileage for brake fluid, just time.


All the German OEMs have specific brake fluid intervals. I think it's safe to say they want to ensure the drivers of their vehicles have optimum performance for the conditions they drive under. Brake maintenance is cheaper than bodywork.

Alfred Teves (Ate), one of the largest foundation brake OEMs that makes both components and fluids, clearly spells out the intervals for their fluids.

With the braking system as an integral part of traction and yaw control systems, not to mention brake-based torque biasing, having a properly maintained system is more important than ever.

 

[cjcride]

Originally Posted By: Colt45ws
I use a pressure bleeder. I used vacuum bleed for a long time, giant PITA. Hose always slips off the bleeder and then you have air, so rebleed time.
With the pressure bleeder, you just pressurize the master, and go around and open every cylinder until it runs clear. I typically use a quart bottle of oil to bleed into so I can monitor how much Im taking out, so I don't over do it and run out.
Simple and clean.
I try to do 2 years, but 3 years is reasonable. If you want, there are strips available that you can dip into your master. It measures the amount of copper present in the fluid and if there is a lot, its time to change.

Colt, I did the exact route you took and agree the pressure bleed is best.
At the 2 or 3 year bleed the DOT 3 always comes out a few shades darker than the new fluid.
Do you think that is rust? If not is it the copper you refer to?

 

[KrisZ]

A proper method is one that exchanges the fluid in the whole system without introducing air into it. There are many ways to accomplish this.

 

[exranger06]

I change my brake fluid once every few years. The old fluid is always black and nasty looking, while the new fluid is a nice clear amber color. Worth it to me to change it.

 

[finmile]

You need to change the brake fluid when it has 3% or more water in it because the boiling point will be reduced too much. My car has still the DOT4 factory fill in it and the water content is no more than 2%. And the car is already 11 years old. So, it can take really long time before the brake fluid must be changed.

The only bad thing in waiting so long is that the bleeder valves will get stuck so bad, that they will probably break/snap when you try to open them => You end up buying new brake calipers.

 

[Ducked]

I used to operate (in the uk) on an "if it ain't broke" basis and got away with it. Perhaps the previous owners of my old cars had been more pro-active.

My old Taiwanese car is teaching me different.

I've learned the hard way that brake fluid deteriorates, that when it does the system can fail quite suddenly, and suffers from corrosion, and once the corrosion has happened brake flushing won't necessarily remove it.

The turkey baster has the advantage that, on a neglected system, you can use it to remove accumulated sludge from the bottom of the master cylinder reservoir, though disassembly is probably indicated in that case.

For flushing I've found gravity or a syringe are both easier and safer than using the brake pedal, and don't involve the purchase of gizmos that are probably not available here anyway.

The syringe is alleged to carry a risk of reversing master cylinder seals. So far so good, touch wood.

 

[Yup]

Buy a Mity Vac. They have rubber nipples that go over the bleeder valve. Keep the reservoir filled, pump up the Mity Vac, it sucks fluid through the line. Suck til it's clear. Tighten valve, move to next tire in bleed sequence. Just make sure you don't let the reservoir go dry. Mity Vac makes it a one man, under an hour job. Before I bought mine, I'd just put the car on Jack stands, pop all four bleeders with pans under them (tubing attached), and keep the reservoir filled while drinking a beer. 15 minutes later they'd go through about a pint of fluid. I figured that was good enough.

Most manufacurers say every 2-3 years regardless of mileage. Also, with ABS the fluid usually stays inside the ABS actuator unless you cycle the ABS while bleeding. So that's something to think about, too.

 

[Yup]

Harbor Freight has them, too. I had a coupon and got mine for about $25.

http://www.northerntool.com/shop/tools/product_391590_391590?cm_mmc=Google-pla&utm_source=Google_PLA&utm_medium=Automotive%20%3E%20Brake%20Repair&utm_campaign=Mityvac&utm_content=33160&ci_src=17588969&ci_sku=33160&gclid=CNz2g-j9ucsCFUZrfgodhm0Flg

 

[Ducked]

Originally Posted By: Yup
Harbor Freight has them, too. I had a coupon and got mine for about $25.

http://www.northerntool.com/shop/tools/product_391590_391590?cm_mmc=Google-pla&utm_source=Google_PLA&utm_medium=Automotive%20%3E%20Brake%20Repair&utm_campaign=Mityvac&utm_content=33160&ci_src=17588969&ci_sku=33160&gclid=CNz2g-j9ucsCFUZrfgodhm0Flg


As far as I can tell, a syringe does the same thing for less than a dollar.

 

[Ducked]

Originally Posted By: Yup
and keep the reservoir filled while drinking a beer.


Seems risky. Drinking brake fluid wouldn't be so bad, but accidentally adding beer to your braking system would be annoying.

 

[slacktide_bitog]

Originally Posted By: Ducked
Seems risky. Drinking brake fluid wouldn't be so bad, but accidentally adding beer to your braking system would be annoying.


Yeah, DOT2 doesn't work as good as the newer stuff

 

[supton]

I use a Mityvac to empty the resevoir, and to pull fluid from the lines. BTW, due to a stuck drain diff drain bolt, same tool let me empty the diff. No fun but it's not a single use tool.

While pulling brake fluid I did have a stream of bubbles in the brake fluid coming out, due to the adapter not seating properly. As long as the air doesn't go back in, no issue. I've done this a few times and no air back into the system.

I'm not sure how much fluid to remove from the system, so as to get fluid all the way through--but IMO, if I do this once a year, the fluid will slowly be exchanged. Given how many never change it and never have a problem, I'm not going to overthink it.

*

As far as never letting the master cylinder hit the floor: I have to wonder if it's best to test it. If it's going to fail, it's best to do it in your driveway. Alternatively, if you do this every year, then that ridge that one is worried about shouldn't build up, right?

 

[andyd]

The Wheel cylinder bores are where the heavier crud ends up with the most water and rust and the lowest point. Right where the brakes are their hottest. That is the stuff you want to get rid of. The better stuff is what you sucked out of the MC using a turkey baster. You have to drain the system just like coolant. You can't let air in too. Brake fade happens with drum brakes when the fluid boils and the system lost pressure. Thats what you're trying to prevent.