brake fluid

[alphatarget1]

It's supposed to be a sealed system... I'm thinking of putting some good DOT 4 fluid (in a DOT 3 system) and just forget about it.

 

[Zenmervolt]

No, it's not a sealed system. Water wicks through the rubber and the plastic reservoir. The fluid is extremely hygroscopic and will actively pull water through the semi-permeable rubber and plastic. You need to change it every two years.

ZV

 

[BUTCH1]

It's a good idea to change it every 3 yrs. or so, even though the system is sealed
the fluid can get contaminated with moisture and can lead to expensive caliper and
or brake line replacement. A simple gravity bleed should do the trick or if your getting
your pads done at a shop ask them to do a complete bleeding..

 

[alphatarget1]

Originally posted by: Zenmervolt
No, it's not a sealed system. Water wicks through the rubber and the plastic reservoir. The fluid is extremely hygroscopic and will actively pull water through the semi-permeable rubber and plastic. You need to change it every two years.

ZV

I'm not entirely convinced that it needs to be changed at a rigid interval. I'd think that it'd depend on the environment in which the car is operated in (if you garage your car, and if you live in a desert area like Phoenix) you probably wouldn't have to change it so often. Maybe it'll get through the cracks in the connections, but without a really high pressure gradient it's really hard to get water through rubber.

Right now I live in TX and it's pretty humid there, so I'm just waiting for my front pads to go and then I'll change it along with the brake fluid. Thanks for all the advice guys. Do y'all think buying "racing" fluid is worth it, as in if I could extend the brake fluid changes?

 

[DonaldC]

Every expert I've read plus most auto companies recommend you flush the brake system every two years.

 

[overst33r]

Originally posted by: alphatarget1

Originally posted by: Zenmervolt
No, it's not a sealed system. Water wicks through the rubber and the plastic reservoir. The fluid is extremely hygroscopic and will actively pull water through the semi-permeable rubber and plastic. You need to change it every two years.

ZV

I'm not entirely convinced that it needs to be changed at a rigid interval. I'd think that it'd depend on the environment in which the car is operated in (if you garage your car, and if you live in a desert area like Phoenix) you probably wouldn't have to change it so often. Maybe it'll get through the cracks in the connections, but without a really high pressure gradient it's really hard to get water through rubber.

Right now I live in TX and it's pretty humid there, so I'm just waiting for my front pads to go and then I'll change it along with the brake fluid. Thanks for all the advice guys. Do y'all think buying "racing" fluid is worth it, as in if I could extend the brake fluid changes?

Do NOT use racing fluids or any other silicone based brake fluid unless you plan on doing a proper flush of the entire brake system (disassemble everything and clean) in addition to changing it every week. It's meant for high stress application, not for longevity AFAIK. Besides, after mixing with your DOT 3/4/5.1 fluid, it could leave precipitates that could mess up the whole braking system which is $$$. I'm sure someone can go into more detail if needed.

 

[DivideBYZero]

Originally posted by: Zenmervolt
No, it's not a sealed system. Water wicks through the rubber and the plastic reservoir. The fluid is extremely hygroscopic and will actively pull water through the semi-permeable rubber and plastic. You need to change it every two years.

ZV

This.

/Thread

 

[dawp]

Originally posted by: alphatarget1
It's supposed to be a sealed system... I'm thinking of putting some good DOT 4 fluid (in a DOT 3 system) and just forget about it.

don't put dot 4 in a dot 3 system, if i remember correctly, they aren't compatible and will require a complete rebuild of the brake system if mixed.if dot 4 is used, it's easier to start fresh in a new system.

 

[T2urtle]

Originally posted by: dawp

Originally posted by: alphatarget1
It's supposed to be a sealed system... I'm thinking of putting some good DOT 4 fluid (in a DOT 3 system) and just forget about it.

don't put dot 4 in a dot 3 system, if i remember correctly, they aren't compatible and will require a complete rebuild of the brake system if mixed.if dot 4 is used, it's easier to start fresh in a new system.

you can put dot4 in a dot 3, but DOT 5 is a whole diffrent type of fluid.

dot 3 has a lower boiling point then DOt 4 i think thats about all its diffrent.


i do it when i change my pads reguardless of what happens. my gf eats thru a set of pads once a year on her car where as i'm about every 2-3 years.

 

[bruceb]

I myself have never changed the brake fluids on my cars. That said, on cars with Antilock brake systems (which is now almost all of them) it is a good idea to change it every 2 - 3 years or it is possible the ABS valves may not work properly. And if they fail, it will be costly. And what was said about brake fluid retaining some moisture is true and the brakes will work better with fluid with as little moisture in it as possible.

 

[Vette73]

The only thing I would add to the 2 year thing is also every brake job if that comes beofre 2 years.



I remember the first time i changed mine. I knew little about cars other then dot4 had a better temp then 3. Seeing as my brake fluid was dark and the new stuff clear i thought lets change it. Now this was when I was 17 and did not even have any real tools. So I went to the car wash and opened the fluid lid (big on older GM cars) and just sucked it out with the vacuum. I am sure the person that had to clean it was not happy at me. Also don;t do that as I am sure they would arrest you for damaging their equipment.

 

[DivideBYZero]

Originally posted by: Marlin1975
The only thing I would add to the 2 year thing is also every brake job if that comes beofre 2 years.



I remember the first time i changed mine. I knew little about cars other then dot4 had a better temp then 3. Seeing as my brake fluid was dark and the new stuff clear i thought lets change it. Now this was when I was 17 and did not even have any real tools. So I went to the car wash and opened the fluid lid (big on older GM cars) and just sucked it out with the vacuum. I am sure the person that had to clean it was not happy at me. Also don;t do that as I am sure they would arrest you for damaging their equipment.

:laugh:

 

[AMCRambler]

From what I've heard you should replace it every so often. I don't know about every two years, but it does pull water into it and as it gets older the boiling point of the fluid drops so that undr hard braking when the brakes get hot and in turn the fluid heats up it will be more likely to boil, which is bad bad bad. Could cause your brakes to go to mush when you need them most. In the four years I've had my Contour I've changed the fluid once and that was last year. The fluid that came out of the system as we bled it was definitely darker and had a more liquid consistency to it leading me to bleieve it had broken down a bit.

 

[sjwaste]

Buy speed bleeders. When you go to bleed the brakes every few years or so, just pump a bit extra out of the caliper after it stops bubbling, top off the reservoir, and repeat for the 3 remaining corners. Then you have bled brakes and new fluid.

 

[radioouman]

I've never replaced the fluid itself on my cars. I've replaced calipers, wheel cylinders, and brake lines (both rubber and steel) that forced me to bleed the system thoroughly.

 

[SearchMaster]

Originally posted by: DivideBYZero

Originally posted by: Marlin1975
The only thing I would add to the 2 year thing is also every brake job if that comes beofre 2 years.



I remember the first time i changed mine. I knew little about cars other then dot4 had a better temp then 3. Seeing as my brake fluid was dark and the new stuff clear i thought lets change it. Now this was when I was 17 and did not even have any real tools. So I went to the car wash and opened the fluid lid (big on older GM cars) and just sucked it out with the vacuum. I am sure the person that had to clean it was not happy at me. Also don;t do that as I am sure they would arrest you for damaging their equipment.

:laugh:

Whoa - you just gave me a great idea for those pesky oil changes!