Flushing out brake fluid [Archive] - GrandAmGT.com Forum

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GAGT7386
09-26-2005, 07:53 AM
Is there any way to flush out the brake lines? I have about 75000 miles and have heard that it helps to get all that old fluid out of there. Also how much brake fluid is needed?

Thanks

atc3434
09-26-2005, 08:17 AM
I'm not sure this is really neccisary unless your experiencing some specific braking problem.

MantaGreen97
09-26-2005, 01:27 PM
I'm not sure this is really neccisary unless your experiencing some specific braking problem.

I have to say this is false. Brake fluid, ideally, should be flushed out and replaced entirely every 2-3 years. It is one of the most overlooked maintenance items on cars. Mainly because it doesn't really affect longevity of components and is therefore not required for warranty maintenance. However "wet" brake fluid (which will certainly be the case after a few years) boils much sooner than dry (new) brake fluid. This contributes to brake fade where a hard stop is made and thereafter you have no brakes. This will happen sooner with old brake fluid than new as it reaches its boiling point sooner.

Short of using a power flushing system, the way to flush brake fluid on your own is fairly simple.

It's the same as bleeding fluid, only you do it at all wheel cylinders/calipers. Raise and support the entire vehicle. Then, starting with the cylinder/caliper furthest from the master cylinder (will usually be the right rear wheel) bleed the system like normal (having an assitant maintain the level in the master cylinder as well as monitoring the tube for bubbles at the wheel being bled)--pump the brakes forcing the brake fluid into the jar until you (or your assitant) notices the fluid appearing entirely clean/new.

Then (ensuring no air bubbles as with normal bleeding) close that bleeder screw (with the pedal depressed, as normal) and proceed to the next wheel closer to the master cylinder and repeat until all 4 wheels are done. It will take probably 1 to 1.5 L of new brake fluid, depending on the master cylinder capacity and the vehicle (length of lines, etc.).

If you use something like ATE SuperBlue or TYP200 (very good brake fluid) you can recognise the new brake fluid as SuperBlue is blue and you'll see the new colour bleeding each caliper/cylinder. The next time you flush if you use ATE TYP200 you can do the same (as the only difference between the two is colour, TYP200 is gold). If you don't want to go to the trouble of finding/getting ATE fluid then I'd suggest something like Valvoline Synpower DOT4 brake fluid, which is available at any auto parts store. You'll have to monitor for fluid condition though, as you won't have a distinct colour difference to go on.

atc3434
09-26-2005, 02:02 PM
All I know is I've had 2 cars before my GA, each we're Buick Century's, a '90 and then an '89, both had over 200k on them before I got rid of them (sold one, the other one got destoryed in a couple accidents by my sister.) So, yea, both cars, over 200k, original brake fluid, no problems. I used to take them to my GrandParents in the Catskill mountains, and I really like to drive a car, so I would work the brakes pretty good, never had any fading. Maybe its important to some cars, but I hold there is money better spent as far as preventative maintenence. Certainly if you were experiencing any kind of fading or poor braking performance, I'd look into it. But if its all working good, I wouldn't worry about it.

GAGT7386
09-26-2005, 03:43 PM
Manta where would I go about getting this colored brake fluid? And how much more is it then regular?

Thanks

MantaGreen97
09-26-2005, 05:48 PM
Manta where would I go about getting this colored brake fluid? And how much more is it then regular?

Thanks

There might be other coloured brake fluids about but the one I know about is made by ATE (also known as Continental Teves, a company involved in the brakes industry since the early 1900s; pioneered hydraulic brakes as well as the first integrated ABS system).

ATE SuperBlue and TYP200 are high performance brake fluids which, as I mentioned above, are the same fluid. TYP200 is a high performance DOT4 fluid which is gold/clear in colour and the SuperBlue is the same except that it is blue coloured. Since the DOT4 specification says that the fluid must not be coloured, Superblue technically isn't DOT4 but performs identically. Personally I think the blue is good for other purposes as well--leak detection, for example.

ATE fluids are used stock in most German cars, I believe; such as BMWs and Audis.

SuperBlue and TYP200 can be found in custom/speed shops, and (more easily) online at various online retailers. It might not be easy to get locally but you can look around and perhaps try your local VW/Audi dealer and see if they have any.

There are better brake fluids, but the ATE SuperBlue Racing/TYP200 Racing fluids seem to have the best price/performance ratio for the regular road-car person. Dry boiling point is 536F and wet boiling point is 396F. This surpasses even the DOT 5.1 standard. 1L will cost you approx $10-$13 US. ATE SuperBlue is better than Motul DOT 5.1 (which costs about the same) but Motul RBF 600 is slightly better at 593F dry, 420F wet but costs over double the price, per mL. (If you're wondering about what the "best" brake fluid is, it is typically considered to be Castrol SRF which was designed strictly for racing and costs an appropriate $70 US per litre!)

You may see some fluids that have a high rated dry boiling points (notably Ford DOT3 fluid--for some reason "Ford" fluid has a higher boiling point than any other DOT3 fluid). However, note that Ford fluid isn't as good (as better fluids) once it gets "wet". In any car where you expect to use the fluid for more than a month or so (i.e. any non-race vehicle) the "wet" boiling point is a much more important and relevant number.

As I said above, if you don't want to mail-order or can't find something like the ATE stuff, I'd say go with the Valvoline Synpower which has 503F dry and 343F wet boiling points, is widely available and shouldn't cost more than $9 US per litre.

NorKoastal
09-26-2005, 06:44 PM
PFYC has that stuff... ^^^^

GAGT7386
09-26-2005, 07:20 PM
alright so i pour this new fluid in b4 i go and pump the brakes to bleed them? or pump all the old fluid out and then add new?

MantaGreen97
09-26-2005, 08:16 PM
alright so i pour this new fluid in b4 i go and pump the brakes to bleed them? or pump all the old fluid out and then add new?

No do not pump all the old fluid out! Like I said it is like a normal bleed procedure only a little longer and you do every wheel. If you're unfamiliar with bleeding brakes you may want to either read up on that and/or let a shop handle flushing the fluid for you... If you let the master cylinder empty then you've got another problem and a bit more work to do as you then have to bleed the master cylinder too!

You can pump out a good bit of fluid from the first cylinder you bleed until it is getting low in the master cylinder and then fill it up to minimise the mixing of the new and old fluid but don't let the master cylinder get too low or go empty or you'll have a lot more work on your hands! As with normal bleeding, ensure you maintain the level in the master cylinder. If you have an assistant with you, make sure he/she checks the level after every few pumps of the pedal so it doesn't go low (either keep holding the pedal down or have them close the bleeder they are monitoring so you don't pull air back in).

Again, though, brake fluid is a critical safety item--if you get/leave air in the system you can literally have no brakes while driving. If you don't know what you're doing or are unsure of a brake bleeding procedure then I would recommend you leave it to someone who does.

Lab Rat
09-27-2005, 06:09 AM
One day coming back from lunch brake I was running a little late and was hammering the old GA pretty good. I had just beat a red light and was really hard on the brakes to get around the corner. Then within a couple hundred yards I had to stop for another red light. WTF, had virtually no brake left. Got to the parking space and checked stuff out. No leak, smoke, nothing. Well after it set awile I tried the brakes again and all was good. My theory is the fluid got to boiling after the first hard braking and then went to mush for the second. So needless to say I believe my fluid needs changing and hope to get to it before winter sets in. But if I drive like an old lady I would never even think there is a problem, only when I am driving a bit more spirited. $.02

GAGT7386
09-27-2005, 06:30 AM
No I am good on the bleeding system, just wanted to know if I added the new stuff in with the old. If I do that, it won't combine with the old or what? So this is the correct way:

- add new fluid
- start with rear right wheel bleed until i see new fluid coming out
- move to next wheel and repeat process (i will see old fluid first correct?)
** this is where i was confused, after doing the first wheel, will i still see old fluid at the next wheel? **
- repeat until all wheels are done
- check fluid level when done

also if i order this from PFYC, then should one bottle cover it?

MantaGreen97
09-27-2005, 11:14 AM
No I am good on the bleeding system, just wanted to know if I added the new stuff in with the old. If I do that, it won't combine with the old or what? So this is the correct way:


Well the new fluid is going to combine with the old no matter what you do, but the goal is to essentially push all of the old and old/new mixed fluid out so it is virtually all new fluid.


- add new fluid
- start with rear right wheel bleed until i see new fluid coming out
- move to next wheel and repeat process (i will see old fluid first correct?)
** this is where i was confused, after doing the first wheel, will i still see old fluid at the next wheel? **


Yeah or you could bleed a bunch of the fluid out until the master cylinder is low first (but not empty) and then refill with new fluid and continue (this would minimise mixing). You may actually have to bleed a bit out before you can add more because depending on your brake pads condition, you might not be able to add any fluid to the cylinder otherwise.

But yes you will see old fluid again at the next wheel because that fluid is still in the line from the master cylinder to that particular brake.


- repeat until all wheels are done
- check fluid level when done

also if i order this from PFYC, then should one bottle cover it?

Yeah that sounds right. I'd buy at least 2 litres of it. You might not need all 2L but it comes in 1L cans (the ATE does at least) and I don't know if 1L would be enough (though it might be); just to be sure I'd go with 2. If you don't need the second can just leave it sealed and store it in a dry place, with some silica perhaps if you think it will be stored for a while. You can also always give or sell it to someone else, if you don't end up opening the second can.

GAGT7386
09-27-2005, 12:49 PM
Alright thanks for all the help Manta. That will be my weekend project.