# Bleeding brake fluid



## By Nature (Apr 30, 2002)

Ok I'll be doing it for my first time by myself.
Open brake reservoir cap and start with farthest from the driver caliper and work your way thru and etc as from sentra.net directions

*When bleeding brakes it is best to manually bleed them as pressure bleeders can cause cavitation and bubbles inside the system*

Is that referring to one-man bleeders? So just do it old fashion manual way?

1. I will only be doing front brakes. Is there an easy way to access/bleed rears without taking wheels off? (I have drums)

2. I will be using a whole brand new braking fluid.. Do I completely dry out MC from old fluid by pumping brakes and then fill new fluid? Or under no circumstances let MC run out of brake fluid, so just add new fluid in with the old one and watch until fresh fluid start to come out of caliper?


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## AznVirus (May 8, 2002)

1. you might be able to get to the rear drums w/o taking the wheel off. taking off the wheels only takes so long.

2. you could flush the entire system, but that will take a lot of brake fluid and a tedious repetitive process. do not let the MC run completely out of brake fluid, as that will trap air bubbles into the system.


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## spdracerUT (Jun 11, 2002)

Get speedbleeders, they're great! it took me a 32 fl oz. bottle to completely flush and bleed all the way around 3 times. Yeah, never let the MC run dry. I wasn't paying attention once and it happened. I STILL have a little air in the system from that after a year.


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## By Nature (Apr 30, 2002)

AznVirus said:


> *taking off the wheels only takes so long.
> *


Thanks. I am limited by only 2 stands and absence of nice garage.. matter of fact not even driveway.. ah.. apartments..


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## By Nature (Apr 30, 2002)

spdracerUT said:


> *Get speedbleeders, they're great! it took me a 32 fl oz. bottle to completely flush and bleed all the way around 3 times. Yeah, never let the MC run dry. I wasn't paying attention once and it happened. I STILL have a little air in the system from that after a year. *


speedbleeders? that sounds like pressure tool that sentra.net warns us about... do they sell them at local stores?


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## shmuck90 (Oct 28, 2002)

You can flush the brake fluid with the speedbleeder? But doesnt flushing mean taking out all the fluid or as much as you can or should i take out as much as i can but not let the system become completely dry? Because i think i need to bleed my brakes because the pedal feel is soft and the fluid is very dark.


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## Guest (Apr 10, 2003)

And last not not least... don't forget to use DOT5 fluid.
This fluid is worth its weight in gold (and does cost about $25 quart)! This fluid has one main advantage over DOT3 (regular brake fluid). This DOT5 silicone based fluid is not hygroscopic. That means it does not readily take up and retain moisture. This is most important to reduce the corrosion/rust that will progress in the system over time. I have used this fluid for many years in many cars with striking results. Not all auto stores carry this fluid... accept no susbstitutes, it must say DOT5 on the container.


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## By Nature (Apr 30, 2002)

*Re: Re: Bleeding brake fluid*



bgriffey said:


> *And last not not least... don't forget to use DOT5 fluid.
> This fluid is worth its weight in gold (and does cost about $25 quart)! This fluid has one main advantage over DOT3 (regular brake fluid). This DOT5 silicone based fluid is not hygroscopic. That means it does not readily take up and retain moisture. This is most important to reduce the corrosion/rust that will progress in the system over time. I have used this fluid for many years in many cars with striking results. Not all auto stores carry this fluid... accept no susbstitutes, it must say DOT5 on the container. *


No, I believe you're mistaken. Well atleast for Sentras.

from sentra.net:

*
DOT 5 is silicon based brake fluid which is a big no-no. Silicon fluid is compressible and you will be plagued with spongy brakes. I have read that DOT 5.0 fluid is thicker and more prone to cavitation produced bubbling also. The major advantage of silicon is that it has a very high boiling point, does not eat paint and does not absorb water from the atmosphere. These properties make it an excellent brake fluid for museum stored cars and such. *


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## shmuck90 (Oct 28, 2002)

so stick with DOT3?


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## Guest (Apr 11, 2003)

*Re: Re: Re: Bleeding brake fluid*

That is nonsense... don't believe everything that's on the net.
If you know anything about the science of hydraulics, then you know that the first statement is assinine... You can't compress a fluid! That is what hydraulics is based on! The rest of it is rubbish also. Aircraft have been using this fluid for many years in brakes and control surface hydraulic cylinders.



By Nature said:


> *No, I believe you're mistaken. Well atleast for Sentras.
> 
> from sentra.net:
> 
> ...


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## By Nature (Apr 30, 2002)

I don't doubt that you possibly know and have more experience more then me, but this is a typical mechanic attitude. 100% correctness.. Search the web for dot 5 brake fluid. every other page says silicone is compressable and causes soft pedal feel, which although is not too big of a deal on a street is a big disadvantage on the track...

or you can show sources that say otherwise


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## bahearn (Jul 15, 2002)

DOT 3 is fine for street use. It's cheap, readily available and won't care too much if you don't change it at the recommended intervals specified by your auto manufacturer. There are some very good DOT 3 fluids out there, including Ford brand and Valvoline.


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## By Nature (Apr 30, 2002)

bahearn said:


> * There are some very good DOT 3 fluids out there, including Ford brand and Valvoline. *


Yeah I've heard good things about Valvoline Synpower


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## shmuck90 (Oct 28, 2002)

so basically flushing it or changing the fluid is just using like a speedbleeder and take syphon 3/4 of it out?


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## Guest (Apr 12, 2003)

Start reading...
http://www.howstuffworks.com/question451.htm

and

http://www.automec.co.uk/cgi/enter.html?target=Silicone_DOT5_Brake_Fluid.html



By Nature said:


> *I don't doubt that you possibly know and have more experience more then me, but this is a typical mechanic attitude. 100% correctness.. Search the web for dot 5 brake fluid. every other page says silicone is compressable and causes soft pedal feel, which although is not too big of a deal on a street is a big disadvantage on the track...
> or you can show sources that say otherwise *


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## By Nature (Apr 30, 2002)

those links aren't conclusive.. howstuffworks talked about it in general theory, not pracitice use and the other link is just selling a product.. why should I trust some vendor... here is however a good link (totally object, searched on google under dot 5 myth, hoping to prove myself wrong). Under Myth#5
http://www.stoptech.com/whitepapers/warped_rotors_myth.htm

I think I am starting to see that DOT 5 maybe a good fluid if you don't drive your car too hard and if you just never wanna deal with braking fluid again. The negatives are that you have to completely flush dot3 or 4 fluid out of the system, which may be easier done in a shop then own driveway and I maintain pedal softness side effect, although I don't know for sure how severe or unnoticable it may be.


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## Guest (Apr 12, 2003)

Well, all I know id that I've been using it for over ten years in seven different vehicles with excellent results. The system stays virtually rust-free indefinately. This helps tremendously by keeping the iron oxide (rust) which is very abrasive, away from the numerous rubber seals in the system. You see, that is why you get wheel cyl/caliper leaks... it's because the rusty DOT3 acts like sandpaper when pistons move in the brake system and it abrades the rubber seals to the point where they loose their abaility to seal properly.

The secret to switching over is simple. You drain as much DOT3 from the master cylinder as possible. Then you refill with DOT5. Drive for maybe a week. The DOT5 is higher density that DOT3 and there for the DOT5 will sink in the system while the DOT3 rises. After a week or so open the master cylinder and if you have a see-through resivoir, you'll will notice that a stratification of layers of the two differnt fluids. Take a turkey baster (or equivalent) and suck the DOT3 from the top stratified layer. Then refill with DOT5. Do this about thrre times at one-week intervals and you will have purged all the DOT3 from the system...



By Nature said:


> *those links aren't conclusive.. howstuffworks talked about it in general theory, not pracitice use and the other link is just selling a product.. why should I trust some vendor... here is however a good link (totally object, searched on google under dot 5 myth, hoping to prove myself wrong). Under Myth#5
> http://www.stoptech.com/whitepapers/warped_rotors_myth.htm
> 
> I think I am starting to see that DOT 5 maybe a good fluid if you don't drive your car too hard and if you just never wanna deal with braking fluid again. The negatives are that you have to completely flush dot3 or 4 fluid out of the system, which may be easier done in a shop then own driveway and I maintain pedal softness side effect, although I don't know for sure how severe or unnoticable it may be. *


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