Brake fluid ?

[ian]

Hi. I recently bought a '90 kdx200 and the guy gave my a box with all the extra oil and fluids he didn't use, including a partly used DOT4 brake fluid bottle, so i assume thats whats in the bike. The manual says to only use DOT3 fluid...but from what i have read DOT4 is just a better quality fluid, so is ot ok to use this? Also, how hard is it to change the fluid? and i don't know how long the bottle i got has be opened, so is it still good to use or should i buy a new sealed bottle?

Thanks!;)

 

[spanky250]

DOT 4 is fine, as long as you flush all of the DOT 3 from the brake system. I use DOT 4. All you need to do is a thorough bleeding, something that is frequently required to keep your brakes performing properly anyway.

Congrats on the new toy, it is a great bike.:cool:

 

[canyncarvr]

OPINION ALERT!!!!!

..but I don't think 3/4 mixing is a problem. Matters not at all.

Flushing the hydraulic system is generally a great idea..but won't matter as far as the mixing part goes.

BUT...mixing DOT5 and ANY lower 'version' results in a jellied mess that will ruin your brake system.

If you don't know how the DOT4 has been taken care of, why bother with it? Brake fluid has to be kept sealed and dry. So...spend a couple bucks and buy some new stuff.

A pressure bleeder is pretty much required on larger systems, but a repeated refill/bleed sequence will do as well on a small system (like the KDX). Repeat until it comes out clear.

 

[NDRO]

And remember to keep plent of fluid in there when bleeding the system.. I hate that suck sound when you think you're just about done...:think

 

[dirt bike dave]

FWIW, Motul 600 fluid cost a couple more $ but has a higher boiling point than the other brands and is DOT3 and DOT4 compatable.

 

[ian]

Thanks for that help, i think i will change the fluid in the winter since i just bought the bike and don't know how long its been, it still looks pretty new, but i'm just that type of person ;) Anyway, what do you pros recommend for fluid?

thanks again,
ian

 

[spanky250]

Re: OPINION ALERT!!!!!

Originally posted by canyncarvr
..but I don't think 3/4 mixing is a problem. Matters not at all.

Flushing the hydraulic system is generally a great idea..but won't matter as far as the mixing part goes.

BUT...mixing DOT5 and ANY lower 'version' results in a jellied mess that will ruin your brake system.

Mixing DOT 3 and 4 doesn't cause problems, but diluting the DOT 4 with DOT 3 will lower the boiling point of the DOT 4 fluid, negating any benefits of using the DOT 4.

 

[Pathfinder4]

Take it from me, use the best - read high boiling point fluid you can.
I have boiled my fluid several times. One second you have brakes the next you dont.

If you brakes ever squeel change fluid!.

Have fun!

 

[Perk]

I've been riding for years, but for the most part I am mechanically ignorant. What does the squelling brakes have to do with the changing of the fluid? Does that signify a boiling point or something?

 

[spanky250]

Originally posted by Perk
What does the squelling brakes have to do with the changing of the fluid?

Absolutely nothing.

 

[Pathfinder4]

Originally posted by spanky250
Absolutely nothing.

If this is true why to my breaks squeel (with new rotor and pads) and then
when I change fluid they don't squeel.

 

[BRush]

Originally posted by Pathfinder4


If this is true why to my breaks squeel (with new rotor and pads) and then
when I change fluid they don't squeel.

Probably coincidence. Maybe you cleaned things up when changing the fluid? My rear brake tends to squeal after a long muddy ride when a lot of mud and crap gets in there and is baked on. Most likely causing uneven pad contact. After washing the bike and cleaning the muck out of the caliper, the brakes don't squeal till the next time. Pad compound seems to make a difference too. The full metallic pads I tried for a while were much more prone to this.

 

[Perk]

That's when mine seem to squeel the most, is during a muddy ride. I can't really think of any instinses when they would squeel otherwise. Nothing that stands out anyway. :silly: