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-   -   Changing brake fluid (https://www.nopistons.com/2nd-generation-specific-17/changing-brake-fluid-6850/)

pengaru 10-22-2002 04:17 PM


Originally Posted by 13BAce' date='Oct 22 2002, 08:51 PM
[quote name='Rob x-7' date='Oct 22 2002, 10:28 AM'][quote name='j9fd3s' date='Oct 22 2002, 12:49 PM'][quote name='Rob x-7' date='Oct 22 2002, 09:12 AM'][quote name='Jims5543' date='Oct 21 2002, 08:12 PM']Speedbleeders are a must. You will need a full can of brake fluid. (8oz)



Hint - go to your local Ford Dealership and ask for heavy duty dot 4 fluid. It is for ford trucks and is really good stuff. It costs $10 for 8 oz. I would buy 2. Its wet boiling point is like 365° that is over 80° more than anything you will find in your autoparts store. I use it for racing and I can get away with not bleading my brakes after every AutoX with this stuff.

Just curious, why wont any DOT 4 or even DOT 5 fluid work? They are both higher temp fluids and heavier duty.

The 'norm' fluid is DOT 3.[/quote]

i think dot 5 is silicone (dd?), its good if you have a show car, but the silicon is compressable so its kinda bad for a car you actually drive. dot 5 also wont eat you paint if you spill.

as far as the others, its all the same to me....



mike[/quote]

Right you are about the 5 being silicone.

Im with you, as long as its DOT 3,4, or 5- its all the same no matter the brands.[/quote]

DOT 3 and DOT 4 can be mixed, but I don't think they can be mixed with DOT 5.[/quote]

Dot5 cannot be mixed with the glycol based brake fluids. Best to use in a car you arent just parking is dot4 or if you have the $$ dot 5.1 which is glycol based also. It's not recommended to mix types. Also, don't use any brake fluid that has been opened and sat around for more than a week... It's designed to absorb moisture but the more moisture it absorbs the more compressable it is so you'll get a more spogy pedal. Open bottles will let moisture in. Use as much as you can immediately after opening... then discard whatever is left... For this reason I generally buy the small bottles of DOT4.... that way I don't waste much when I throw away open bottles without using all of it. (or you could go to your families cars and top them off with the remainder assuming it's the same stuff https://www.nopistons.com/forums/pub...DIR )

FCmaniac 10-22-2002 06:36 PM

Thanks for all the good info guys! I was going to get Motul 600 but thats a good tip on the Ford stuff and much cheaper too...

can't wait

:bigthumg:

Jims5543 10-22-2002 09:02 PM

That Ford heavy Duty is the ****!! Go read some cans of DOT 3 or DOT 4. I didn't believe it either until I read it myself that Forrd Heavy duty has a really high wet boiling point.



If you are Autocrossing you "should" bleed your brakes after each event. You dont have to do the resivoir thing after you do the initial one.



I never heard of brake fluid absorbing moisture from the air. I was under the impression the high heat of the brake caliper breaks it down and causes condensation in the line hence the dry and wet boiling points.

horn4858 10-22-2002 09:07 PM

you can use 5 but it must be a fresh system. new seals and no remnants of anything else. https://www.nopistons.com/forums/pub...IR#>/beer2.gif

1988RedT2 10-22-2002 09:15 PM


Originally Posted by Jims5543' date='Oct 23 2002, 02:02 AM
I never heard of brake fluid absorbing moisture from the air. I was under the impression the high heat of the brake caliper breaks it down and causes condensation in the line hence the dry and wet boiling points.



ABC's of Brake Fluid



Brake fluid does absorb water from anything, including air...DOT #3 and DOT #4 brake fluids are made from Polyalkylene Glycol Ether which, by nature, has a very strong attraction to water (brake fluid is hygroscopic). Water contaminating brake fluid makes its boiling point drop which causes bubbles to form in the brake fluid (imagine sprinkling water into a frying pan full of hot oil). Bubbles and water are more compressible than brake fluid which makes it more difficult for the master cylinder to compress the brake fluid and in turn, compress the calipers and brake drums. A sign of this may be a low, soft, or spongy brake pedal feel (caused by the the contaminating bubbles and water compressing before the brake fluid does).


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